Tag Archives: coffee

Climate change is after our coffee (and other key food crops too)

The world is warming up fast, and areas that are currently being used to grow important food crops such as coffee beans, cashews, and avocados will no longer be suitable in a few years. According to new research, we’d be wise to come up with urgent adaptation measures to cope with the impact climate change will have on food security. 

A coffee farm in Peru. Image credit: Flickr / Orientalizing.

A global warming of 1.2°C up to 3°C is expected by the end of the century, depending on how much real action we take to reduce our greenhouse gas emissions. Such changes in temperatures will affect the climate suitability of crop regions around the world, causing big shifts and forcing countries to rethink agricultural practices.

The food we eat depends on a variety of soil and climate conditions to grow, and any changes to these, from temperature to rainfall, can mean bad news for crops. Adapting to climate change is not straightforward. When temperatures rise and become unsuitable for a crop, it’s not like you can simply take that crop and move it somewhere colder, because this colder area may not have the same soil or humidity conditions. Many previous studies have explored how agriculture would be affected by climate change, and the findings anticipate trouble for many staplec crops, including maize, wheat, soy and corn. 

Now, a group of researchers led by environmental systems scientist Roman Grüter focused on three popular foods, coffee, cashers and avocados, and how will they change in the next 30 years. The researchers found a dynamic of winners and losers, with large areas that won’t be suitable for crops anymore and some that will benefit but overall, the effects will be negative.

“This study presents the first global evaluation of coffee arabica, cashew and avocado suitability combining both climate and soil factors”, the researchers wrote in the journal PLOS ONE. “High annual temperatures, low minimum temperatures, long dry seasons and low or high precipitation were the most relevant climate criteria.”

A changing climate

The researchers combined information about the climate conditions the crops prefer with maps of climate data and soil and land types. Then, they predicted where conditions would decline or improve based on climate models. The maps they produced are so precise that they can zoom in to one square kilometer in resolution.

Of the three crops studied, coffee was found to be the most affected by climate change. By 2050, in all realistic climate scenarios, the number of regions most suited to grow Arabica, the main coffee variety, will decrease by at least 50%. This is mainly due to a higher annual temperature in coffee-producing countries such as Brazil, Vietnam and Colombia.

Avocados had varied results. The region’s best suited areas for avocados (in countries such as Indonesia) would decline between 14% to 41% around the world but the regions moderately suited for growing the fruit increased by 12% to 20%. For cashew, land suitable for crops is expected to increase 17% thanks to warm winters in high and low latitudes. 

The researchers highlighted that while changes in rainfall patterns and the rise in temperature might make some areas more suitable for crops, this could also mean more forests converted to farmland. Avocado, for example, has already led to a spike in deforestation in Indonesia and Mexico in order to meet a growing demand of the fruit. 

The crops in the study represent an important source of income for farmers around the world, especially smallholders. Many could see their farms and livelihoods affected by climate change. That’s why policy makers and farmers should start working on how they are going to adapt to this new reality, which could get worse on the years to come. 

“Adaptation measures can include site-specific management options, plant breeding efforts for varieties that are better adapted to higher temperatures or drought and in the case of coffee, replacement of arabica with robusta coffee in certain regions. New production locations at higher altitudes and latitudes might create new market opportunities,” the researchers wrote.

The study was published in the journal PLOS ONE. 

Finnish researchers aim to bring lab-grown coffee to the markets in around four years’ time

Researchers working at Finland’s VTT technical research institute are working hard to find new ways for us to get our morning cup of joe. Their efforts recently paid off, as the team successfully developed lab-grown coffee.

Coffee cell cultures (right) and roasted coffee produced at the VTT. Image credits VTT Research.

Most of us rely heavily on coffee to get us going in the morning, every morning. But the sheer demand for coffee has caused its share of environmental issues. The plant is quite picky in regards to soil and climate, which has led to wide areas of unique ecosystems being leveled to clear the way for plantations, for example.

The research at VTT, however, is paving the way towards a more sustainable and eco-friendly method of growing coffee. In the long term, the team hopes that such an approach will allow us to conserve vital ecosystems while still getting to enjoy a high-quality roast.

Better latte than never

“It’s really coffee, because there is nothing other than coffee material in the product,” said Dr Heiko Rischer from VTT, who led the research effort.

This coffee is the real deal, although it doesn’t come in bean form. It’s actually grown from a cluster of coffee cells in a bioreactor, under the ideal temperature, light, and oxygen conditions to allow them to thrive. As an approach, it’s not that different from the way lab-grown meat is being produced.

All of this yields a powder that, after roasting, tastes, smells, and behaves just like conventional coffee. It can also be brewed into coffee that’s indistinguishable from the regular drink.

Apart from the damage caused to the environment as plantations expand, rising average temperatures are also making coffee plantations around the world less productive. This, in turn, means that farmers are forced to clear away ever-larger areas of the rainforest to keep up with demand. This new approach could help offset some of that demand while also helping restore ecosystems and combating climate change.

“Coffee is of course a problematic product,” Rischer said. “There is the transport issue, the fossil fuel use… so it totally makes sense to look for alternatives.”

For now, the team is still hard at work analyzing the lab-grown coffee and assessing how sustainable and practical it would be to manufacture it on a large scale. The data so far points to it requiring less labour and resources to grow than conventional coffee, however. Water use, in particular, seems to be an area where lab-grown coffee has a definite edge over its conventional alternative.

Naturally, what matters most for consumers will be how coffee brewed from this powder tastes in comparison to the regular brew. So far, a panel of specialists is taste-testing the product, although they’re only allowed “to taste and spit, but not swallow it,” as the lab-grown coffee is classified as a “novel food”. However, they report that this coffee is less bitter compared to regular coffee — which could come down to a slightly lower caffeine content — and tastes a tad less fruity.

“But that being said, we really have to admit that we are not professional coffee roasters and a lot of the flavour generation actually happens in the roasting process,” Rischer said.

The team estimates that we could see their lab-grown coffee commercially available in a minimum of four years, during which time they’ll work to perfect the product, gain regulatory approval, and commercial backing.

Six cups of coffee a day is enough to start damaging your brain

A coffee each morning can work as a quick pick-me-up. But don’t go overboard, researchers from the University of South Australia warn, as it could negatively impact your brain’s health.

Image credits Karolina Grabowska.

One of the largest studies of its kind reports that high coffee consumption is associated with an increased risk of dementia and smaller total brain volumes. The study included data from 17,702 UK Biobank participants aged 37-73, finding that those who drank six or more cups of coffee per day had a 53% increased risk of dementia, and showed reduced volumes in their overall brains, white matter, gray matter, and their hippocampus.

Brain drain

“Coffee is among the most popular drinks in the world. Yet with global consumption being more than nine billion kilograms a year, it’s critical that we understand any potential health implications,” says Kitty Pham, lead researcher on the paper and a Ph.D. candidate at the University of South Australia (UniSA). “This is the most extensive investigation into the connections between coffee, brain volume measurements, the risks of dementia, and the risks of stroke—it’s also the largest study to consider volumetric brain imaging data and a wide range of confounding factors.

“Accounting for all possible permutations, we consistently found that higher coffee consumption was significantly associated with reduced brain volume—essentially, drinking more than six cups of coffee a day may be putting you at risk of brain diseases such as dementia and stroke.”

Although I personally know nobody who actually drinks six or more cups of coffee a day, there are certainly a few out there. As such, the findings could be quite important for public health, pointing to a source of preventable brain damage, including stroke and dementia.

Dementia affects about 50 million people worldwide, affecting an individual’s ability to think, their memory, impacting their behavior, and their ability to perform even everyday tasks. It’s a degenerative brain condition and a sizeable cause of death worldwide.

Strokes involve the disruption of blood flow to the brain, usually through blood clots or the rupturing of blood vessels, and end up starving areas of the brain of oxygen. This, in turn, leads to (usually significant) brain damage and loss of function. They’re surprisingly common, affecting one in four adults over the age of 25 worldwide.

The team explains that the exact mechanism through which excessive caffeine can impact brain health is not yet known but these results — along with previous research on the topic — make a strong argument that it does have such an effect. Still, this doesn’t mean you have to put your cup down for good. Moderation is the name of the game, the team explains.

“This research provides vital insights about heavy coffee consumption and brain health, but as with many things in life, moderation is the key,” says Professor Elina Hyppönen, senior investigator and Director of UniSA’s Australian Centre for Precision Health.

“Together with other genetic evidence and a randomized controlled trial, these data strongly suggest that high coffee consumption can adversely affect brain health. While the exact mechanisms are not known, one simple thing we can do is to keep hydrated and remember to drink a bit of water alongside that cup of coffee.

People typically consume between one and two cups of coffee per day, the team adds, which is not a very accurate measure, as cups are quite variable. Still, such low levels of intake should be fine. As long as you’re not closing in on five of six cups a day, they conclude, you should be safe.

The paper “High coffee consumption, brain volume and risk of dementia and stroke” has been published in the journal Nutritional Neuroscience.

That morning cup of coffee? It’s not enough to tackle sleep deprivation

If you stayed up all night catching up on Netflix or if your neighbor’s dog was too noisy and you couldn’t sleep, a big coffee in the morning is usually the way to power through the rest of the day. As it turns out, caffeine can only get you so far. 

Image credit: Flickr / Jen.

Caffeine is a fast-acting stimulant that works on the central nervous system. It can increase blood pressure and heart rate, boost energy levels, and improve overall mood. Coffee accounts for 54% of caffeine consumption in the world, while tea accounts for another 43%. A normal dose is about 50 mg to 200 milligrams. 

We can experience the effects of caffeine right after consuming it, and the effects will continue to last for as long as the caffeine remains in your body. According to the US Academy of Sleep Medicine, caffeine’s half-life is up to 5 hours. However, many people see it as a magical cure against sleep deprivation — and that it is not.

Now, researchers from Michigan State University’s Sleep and Learning Lab looked at how effective caffeine was in counteracting the negative effects of sleep deprivation on cognition. They assessed the impact of caffeine after a night of sleep deprivation, asking 275 participants to complete a set of tasks, from simple to difficult ones. 

Participants were randomly assigned to either stay awake overnight in the lab or sleep at home. In the morning, those who slept returned to the lab, and all participants consumed a capsule that contained either 200 mg of caffeine or a placebo. After an absorption period, all participants completed simple and complex attention tasks. 

The researchers found that sleep deprivation impaired performance on both types of tasks and that having caffeine helped people successfully achieve the easier task. However, caffeine had a limited effect on performance on the complex tasks, which he participants had to be do in a specific order without skipping or repeating steps. 

“Caffeine may improve the ability to stay awake and attend to a task, but it doesn’t do much to prevent the sort of procedural errors that can cause things like medical mistakes and car accidents,” Kimberly Fenn, lead author, explained the findings in a statement. “Caffeine increases energy and reduces sleepiness but it absolutely does not replace a full night of sleep.”

Fenn and her team highlighted that while people may fell that they can tackle sleep deprivation with caffeine, their performance on higher-level tasks will likely be affected – as seen in the study. This is why sleep deprivation can be dangerous. Lacking adequate sleep affects cognition, alters mood and can take a toll on immunity, they added. 

That’s why it’s important to consider other ways to naturally increase your energy levels without caffeine. Some of the following options can help: drinking more water, eating lots of plant-based food, which may provide energy, exercising daily, but not too close to bedtime, avoiding long daytime naps and getting at least 7 hours of sleep — preferably 8 or more.

“If we had found that caffeine significantly reduced procedural errors under conditions of sleep deprivation, this would have broad implications for individuals who must perform high stakes procedures with insufficient sleep, like surgeons, pilots and police officers. Instead, our findings underscore the importance of prioritizing sleep,” Fenn said. 

The study was published in the Journal of Experimental Psychology: Learning, Memory, and Cognition.

The ground coffee you buy at the shops could soon get much better

Soon, coffee lovers around the world might find a new exciting option in supermarkets, one that researchers promise will significantly improve their drinking experience. It’s cryo-ground coffee: produced with beans cooled at -100ºC and then ground. It’s healthier, tastes better, and has a better aroma, proponents say. 

Image credit: Flickr / Joe King

Most coffee buyers prefer ground coffee to whole beans, but preferences can vary across the world. Ground coffee accounts for 60% and 45% of the retail coffee markets in Russia and Germany, respectively. The main argument against ground coffee is that it doesn’t usually have the same high-quality features that whole beans have. This could soon change thanks to a new cryogenic grinding technology.

A team of Russian researchers from the Skotelch came across a paper in the journal Nature last year that described how roasted coffee beans were cooled to ultra-low temperature and then grounded in a mill. The study showed that grinding at those temperatures increased the uniformity of the particles by 15-20%. 

“Cryogrinding is a complex process that needs to achieve three independent objectives at the same time: maximize coffee oil preservation for improved aroma and healthiness, maximize particle homogeneity for taste clarity, and minimize ownership cost of equipment (including energy) and as a result the price for consumers,” Smirnov told ZME Science. 

The finding inspired Smirnov and a group of researchers to do their own experiments. Comparing coffee ground from beans cooled to -100 °C to the beans ground at room temperature, they discovered that the latter looked damper and stickier than the dry and powdery cryoground coffee, which hints at desirable coffee properties.

Regular (left) and cryogenic (right) grinding. Credit: Coffeehouse Seneca.

In regular grinding, the researchers explained, aromatic coffee oils are squeezed out through micropores in the coffee particles, react with oxygen, and volatilize. This means that the brewed coffee has far fewer aromatic and healthy components. But in the cryogenic ground, frozen oils can’t escape through the micropores – retaining the freshness, aroma, and health benefits for longer. 

“Uniformity means that there are fewer particles that are too small or too large. Smaller particles add a bitter taste, while large ones make the coffee watery. When off-size particles are few, the brewed coffee has a more vivid taste without a trace of bitterness,” Dima Smirnov, Skoltech graduate, explains in a statement.

While it sounds much better than the regular kind, the technology to introduce cryogenic grinding in the retail sector isn’t truly available. In 2014, Russian researchers created a cryogenic cooling system that reduced costs significantly. Now, they improved the system’s performance even further and launched a pilot production facility under the brand Coffeehouse Ground

The researchers believe that this way of producing coffee will be cost-efficient and sustainable in the short term, allowing people to buy it in stores. Later on, the equipment could be optimized even further in order to be used in coffee shops and restaurants. The equipment can be scaled up to produce 50 kilograms of coffee per day but with more research, it could be scaled even further. 

Climate change really ruins everything — now, it’s coming for our coffee

Just like it’s affecting other sectors of agriculture, climate change is starting to pose problems to coffee production. Colombia, the third-largest coffee producer in the world, is going through some serious trouble keeping up production, a new study showed.

Image credit: Flickr / CIFOR

Coffee is one of the biggest crops in Colombia. Up to 550,000 families depend directly on coffee production for their livelihoods and many more depend on it indirectly. Due to changing climate conditions, there have been increasing concerns about the future quantity and quality of the coffee yield in Colombia in the decades to come. A new study shows that people are right to be concerned.

Coffee is very sensitive to unpredictable weather. Studies estimated that a 2ºC increase in temperature would lead to losses in productivity of up to 34% for Mexico and 20% for Brazil, respectively. When it comes to Colombia, the findings forecasted a 4–24% increase in yields in the scenario where temperatures increase not more than 2 ◦C. However, this is highly dependent on the region.

Previous studies have also shown that the mountain region, where coffee is grown in Colombia, is warming by 0.3 degrees Celsius (0.5 degrees Fahrenheit) per decade. Plus the number of hours of sunlight also has declined by 19% since the middle of the last century due to increasing cloud cover – with not enough sun to sustain a high level of production in some areas.

“The Andes Mountains cross Colombia from its southwest to the northeast corner. Colombian coffee is currently growing in areas with different altitude levels, and climate impacts will likely be very different for low altitude and high-altitude regions,” Sandy Dall’Erba, co-author of the new study and agricultural researcher, said in a statement.

Dall’Erba and a group of researchers looked at climate and coffee production for the entire territory of Colombia. They worked with a data set of 521 coffee-producing municipalities that continuously registered at least one hectare of Arabica coffee production from 2007 to 2013. This high level of detail allowed researchers to identify significant regional variations.

Working with climate models, the researchers anticipated weather conditions from 2042 to 2061 and future coffee production for each municipal area. They found that low-altitude municipalities will be negatively affected by climate change over the coming years – with thousands of families seeing their livelihood affected in consequence.

“Colombia is not going to experience reduced productivity overall. But when we look into the impact across municipalities, we see many differences that get lost in the national average. That has important implications for coffee growers who live in one municipality versus another,” lead-author Federico Ceballos-Sierra said in a statement.

At the national level, productivity of coffee production will increase 7.6% by 2061, the study showed. But the forecasts change when zooming in specific regions. High-altitude regions in Colombia (1,500 meters or 5,000 feet above sea level) are expected to have a 16% increase in productivity, while low-altitude regions would have an 8.1% decrease.

This means that a higher temperature because of climate change will affect the current prime coffee growing locations, turning them into areas too hot and dry for production, while benefiting areas that now are considered marginal for coffee production. Smallholder coffee growers will have to find ways to adapt, using strategies such as more frequency irrigation. Although the study focused on Colombia, many other coffee-growing areas likely face similar pressures.

“Our research presents what we anticipate will happen 20 to 40 years from now, given current conditions and practices. Future studies can look into different adaptation strategies and their costs, and evaluate which options are best. Beyond the 40-year horizon we focus on, the prospects might be grimmer without adaptation. Production cannot keep moving to higher levels,” Dall’Erba said in a statement.

The study was published in the journal Agricultural Systems.

Coffee waste can help restore degraded land and forests

That caffeine boost that kickstarts your day may also help restore degraded land and forests, according to a new study.

Researchers dumped 30 dump truck loads of coffee pulp (a waste product of coffee production) on a piece of degraded land in Costa Rica, bringing it back to life with impressive results.

The land in Costa Rica with the coffee pulp on top. Credit: The researchers

Degraded land is an umbrella term that refers to plots of land with low carbon stocks — in other words, with low productivity. Often, the term is used for areas degraded by human activity. These soils typically have minimal tree cover and an absence of peat, so they do not contain or sequester as much carbon as natural forests do.

Around 12% (two billion hectares) of the earth’s terrestrial surface is degraded, with a 2007 study noting that annual costs of land degradation due to land use and land cover change are about $231 billion per year.

Land restoration is critical to tackling some of the world’s biggest challenges, such as global food security, access to clean water, soil erosion, climate change, loss of biodiversity, and desertification. Politicians are also starting to take notice of this issue, and through initiatives such as the Bonn Challenge and the Initiative 20×20, they’ve have set ambitious targets on soil restoration.

But solutions are challenging.

Nutrient-rich agricultural by-products, including fruit peels, pulp, and other non-market vegetable material, have been proposed to help tropical forest recovery on degraded land. Nevertheless, trials in a restoration context have been limited so far. The most well-known study was done in Costa Rica in 1988 with orange waste in a degraded pasture.

Now, researchers are looking at coffee pulp as a potential cost-effective way to address degraded land.

“Adding a nutrient-rich layer, like orange peels or coffee pulp, can overcome some major barrier to natural forest recovery. Unlike planting trees, this approach creates conditions in which forests can establish in a more natural way and be much more cost-effective. So, the potential for using organic waste for restoration is very high,” Rebecca Cole, lead author of the new study, told ZME Science.

Cole and her team of researchers focused on the use of coffee fruit pulp. The processing of coffee beans involves the separation of the seed from the components of the fruit, including the skin, the pulp, and the mucilage. The pulp, which comprises more than 50% by weight of the coffee harvest, is treated as a waste product and heaped into storage lots where it is left to decompose.

But there’s actually much more than could be done with the pulp. Coffee is rich in carbohydrates and crude protein and when processed, forms a valuable compost. With this in mind, the researchers decided to spread the pulp on degraded land in Costa Rica, marking out a similar-sized area without coffee pulp as a control. The results were impressive.

“Adding a 1/2-meter-deep layer of coffee pulp killed the aggressive pasture grass that prevents tree seedlings from establishing. Native herbaceous vegetation and tree seeds that arrived by wind or were dispersed by animals like birds and bats quickly established on the surface of the layer. In only two years, these naturally establishing trees grew and formed a new forest.,” Cole added.

The researchers started the experiment in 2018, selecting two areas of the same size in Costa Rica but leaving one as a control. They analyzed the soil samples for nutrients before applying the coffee pulp and again two years later. They also kept a record of the species present in the land, the percentage of forest ground cover, and the size of woody stems – even using drones to record the canopy cover.

While excited about the results, Cole argued further research will be necessary to test the use of coffee pulp to aid forest restoration. The study was done only at one large site, so further testing will be needed to see if this strategy works at a broader range of conditions. A limitation of using coffee pulp is that its use its limited to relatively flat and accessible areas where the material can be delivered.

“Understanding where coffee pulp is most likely to help forest grow back will enable it to be used more efficiently. Understanding the effects that adding coffee pulp has on soils over time will also help us understand how the new forests will develop. We hope that this will lead to more testing of other agricultural by-products for restoration,” Cole told ZME News

The study was published in the journal Ecological Solutions and Evidence.

It’s time to ditch the disposable cup. But many barriers still stand in the way

They’re lightweight, easy to handle, and basically free — we don’t think about them too much, but single-use coffee cups almost sound too good to be true. Alas, in a way, they really are too good to be true. Takeaway coffee cups are filling the world’s landfills with needless plastic.

Drinkers may be willing to switch to a reusable cup, but a study found that the absence of waste infrastructure and the world’s “throwaway” culture is limiting sustainable change.

Image credit: Flickr / John Beans

Despite being largely made of paper, the interior of disposable coffee cups have is layered with plastic polyethylene that is bonded to the paper – making the cups waterproof and able to contain hot liquid. This makes them much more difficult to be recycled. They still are technically recyclable (something that companies like to promote on the packaging, but in practice, this rarely happens in most countries.

The cups can’t be recycled at standard recycling plants and have to be taken instead to special facilities, which are lacking in most parts of the world. That’s why your coffee cups usually end up in landfills with the rest of the trash, taking hundreds of years to break down and polluting the environment. Gradual breakdown results in microplastics that can be ingested by animals and potentially toxic chemicals.

But that’s not the only problem. Many paper cups that are disposed of are made from virgin paper pulp, which means trees are taken down to produce a product that will last for a very limited period of time. Add to this the carbon footprint of manufacturing the cup and the distribution, concluding in a major impact on the global environment.

Reusable cups are the way to go

Seeking to better understand the problem, researchers from the University of South Australia explored the enablers and barriers that impact the adoption of environment-friendly takeaway coffee cups. To do so, they carried out in-depth interviews and non-participant observations with consumers and stakeholders.

For Sukhbir Sandhu, lead researcher, change is required at all levels, from individuals to retailers.

“There’s no doubt we live in a disposable society – so much of our lives is about convenient, on-the-run transactions. But such a speedy pace encourages the ‘takeaway and throwaway’ culture that we so desperately need to change,” Sandhu said in a statement.

“With the popularity of arty, patterned paper cups on the rise, you may think you’re buying a recyclable option. But no – most takeaway coffee cups are in fact lined with a waterproof plastic, which is not only non-recyclable, but also a contaminant.

The study showed consumers continue to buy coffee no matter the lack of recyclable or compostable cup in coffee shops, and factors such as packaging that look similar to reusable cups is limiting effective changes. This adds up to the lack of suitable waste disposal infrastructure in shops, such as having organic bins for consumers to throw away their compostable cups.

“Educating and informing people about the issues of single-use coffee cups is effective – people generally want to do the right thing – but knowing what’s right and acting upon it are two different things, and at the moment, there are several barriers that are impeding potential progress,” Sandhu said. “For example, if your favorite coffee shop doesn’t offer recyclable or compostable cups, it’s unlikely to stop you.”

The researchers argued that environmental messaging and pro-environmental behavior are necessary to change consumers’ preferences regarding takeaway coffee cups. This has to be accompanied by broader institutional changes, such as providing waste disposal infrastructure and altering monetary incentives for disposing takeaway cups.

The key aspect is that consumers are aware and try to make environmentally conscious decisions. This, in turn, can drive change in sellers.

“It’s important to drive home clear, strong messages about single-use plastics and their impact on the environment,” Dr. Sandhu says. “The more we can drive people to choose reusable cups, the more uptake we’ll see. People like to mimic what their colleagues, friends and peers do, especially when it is the right thing.”

The study was published in the Journal of Cleaner Production.

Drinking coffee daily is associated with less gray matter in the brain

Credit: Pixabay.

A surprising new study found daily caffeine consumption alters the brain’s structure. Specifically, those who regularly used caffeine had less gray matter volume in their brains compared to those that didn’t use the drug at all. The researchers caution that this doesn’t mean that caffeine causes negative cognitive effects. So, don’t throw out your coffee from the cupboard just yet.

It seems like every day there’s a new scientific study on coffee’s effects on our health. Some report that caffeine has positive effects while others report on its downsides. It’s not rare to find two different studies reaching two seemingly opposite conclusions. If you’re confused, you’re not alone.

Luckily, despite some occasional confusing conclusions, the net effect of caffeine seems to be positive. Moderate caffeine intake increases the metabolism promoting weight loss, reduces the risk of type 2 diabetes significantly, lowers the risk for cardiovascular diseases, and represents an important source of antioxidants.

Caffeine also seems to offer protective effects for the brain. Besides stimulating dopamine and glutamate, which makes you start feeling alert and awake, caffeine has been associated with slowing cognitive decline due to Alzheimer’s and Parkinson’s.

But that’s not all it does. While caffeine makes us more alert during the day, it can also disrupt sleep if consumed in the evening or close to bedtime. Previous research showed that sleep deprivation is associated with changes in the gray matter of the brain.

Gray matter, named for its pinkish-gray color, is home to neuronal cell bodies, axon terminals, and dendrites, as well as all nerve synapses. White matter areas of the brain mainly consist of myelinated axons, which form connections between brain cells.

In a new study, researchers from the University of Basel wanted to investigate more closely whether caffeine consumption can affect brain structure.

The researchers recruited 20 healthy individuals, all of whom drink coffee on a daily basis. Each participant was given tablets over two 10-day periods, during which they had to abstain from consuming any caffeine products.

During one 10-day window, the tablets that they were given contained caffeine, while in the other period the tablets had no active ingredient, acting as the placebo or control group.

At the end of each 10-day period, the subjects’ gray matter volume was measured by scanning the brain. Sleep quality was also assessed by recording the electrical activity of the brain with EEG.

The results were rather surprising. The data comparison between the two groups showed no significant differences in the depth and quality of sleep. In other words, those who ingested the caffeine tablets didn’t show signs of sleep deprivation.

However, the group that ingested the caffeine tablets saw a significant decrease in gray matter volume. The difference was particularly striking in the right medial temporal lobe, including the hippocampus, a region of the brain that is essential to memory consolidation, the researchers wrote. They add that these results are not actually concerning.

“Our results do not necessarily mean that caffeine consumption has a negative impact on the brain,” Dr. Carolin Reichert of the University of Basel said in a statement . “But daily caffeine consumption evidently affects our cognitive hardware, which in itself should give rise to further studies.” 

Previous studies that have analyzed gray matter in association with caffeine intake have tended to focus on older patients, rather than young healthy subjects as in the present study. This may explain why the kind of temporary neural plasticity reported by the study has not been observed before.

“The changes in brain morphology seem to be temporary, but systematic comparisons between coffee drinkers and those who usually consume little or no caffeine have so far been lacking,” says Reichert.

The findings appeared in the journal Cerebral Cortex.

Your daily coffee has a big climate cost — here’s how to reduce it by 77%

Coffee, our essential ally for many rough mornings, has a hidden environmental cost that is contributing to the world’s climate crisis, a new study showed. Still, there are plenty of ways to address this challenge that could bring coffee’s emissions down up to 77%, from shipping the beans with cargo ships to using more renewable energy in the process.

Image credit: Flickr / McKay Savage

Grown in tropical regions with fragile ecosystems, coffee is one of the most traded products in the world. Over 9.5 billion kilograms are produced every year, with a trade value of more than $30 billion. Demand is expected to triple by 2050, which has accelerated sustainability initiatives among coffee producers.

Conventional coffee production uses substantial amounts of energy, water, and land, which can have potentially significant impacts on biodiversity. This is mainly due to the long supply chain required to produce and transport the coffee bean to the market. The EU and the US import two-third of the coffee produced worldwide.

Although there has been substantial research into the environmental impacts of coffee production, it has primarily focused on the production phase. Significantly less consideration has been given to the environmental cost of coffee processing, including transportation from the production to consumption countries.

In a recent effort, UK researchers Carmen Nab and Mark Maslin calculated and compared the carbon footprints of conventional and sustainable Arabica coffee, the beans baristas use to make a high-quality brew, from leading producers Brazil and Vietnam. Together, both countries produce over 50% of the world’s Arabica coffee.

Conventional coffee from Vietnam was calculated to have the highest carbon footprint, with 16.04 kilogram of carbon dioxide (CO2) emissions per kilogram of coffee, closely followed by the one produced in Brazil (14.61 kilograms of CO2). Meanwhile, emissions from sustainable coffee were much lower in both cases, averaging 3.40 kilogram.

The exportation and transport process produced over 70% of total CO2 emissions in conventional coffee from both countries. The processing phase was the second-largest source of emissions (19%–21%) followed by the growing (7%) and milling (1%) phases. In the case of sustainable coffee, the processing phase was the largest source of emissions.

The researchers also calculated that just one espresso has an average carbon footprint of about 0.28 kilogram of CO2 emissions. And the figure grows significantly if the coffee has milk. Lattes have a carbon footprint of about 0.55 kg, followed by cappuccinos on 0.41 kg and flat whites on 0.34 kg, they estimated.

“Weight for weight, the coffee produced by the least sustainable means generates as much carbon dioxide as cheese and has a carbon footprint only half that of one of the worst offenders—beef. And that’s all before adding milk, which carries its own hefty environmental baggage,” Nab and Masling wrote in a blog post.

The sustainable case studies quantified in this study had an estimated 77% lower carbon footprint than the conventional case studies. The use of cargo ships for the transportation of coffee beans reduced emissions significatively, as it can export larger shipments at once. The replacement of chemical fertilizers with organic waste also played a big role.

But there are many other things that coffee producers could incorporate and reduce their emissions even further, the researchers argued:

  • Use of recycled materials and reduction of packaging amount. This reduces the demand for primary materials, thus reducing energy, water, and material consumption, air and water emissions in the production of packaging materials, and impacts on biodiversity from forestry and mining
  • Increasing efficiency in water heating. In the processing phase, an estimated 70% of CO2 emissions were attributed to consumption, largely due to the significant energy use of automatic coffee machines. This energy use could be reduced by using more efficient water-using technologies.
  • Use of renewable energy sources. The use of fossil fuels for electricity and energy production releases significant air emissions during each phase of the coffee life cycle. The use of renewable energy sources can reduce the carbon footprint of crop production by up to 70%.
  • Roasting the coffee beans in the producing country. Currently, coffee is usually exported to the country of consumption before it is roasted, allowing retailers to market their coffee as “freshly roasted.” Whilst green coffee beans have a longer shelf life than roasted ones, roasted coffee beans can retain their fresh taste for up to six months if stored at a cool temperature.

The study was published in the journal Royal Geographical Society.

How Are The Best Coffee Beans In The World Grown?

They get you up in the morning, and they keep you running till late evening — but how is coffee grown?

Image via Pixabay.

Boiled down (pun intended), coffee is produced from the seeds of the coffee tree. These seeds develop inside fruits known as coffee berries and are usually found in pairs inside each berry. When tomato-red, the fruits are ready to be harvested, the pits collected, dried, and shipped to a grocery store near you.

That, however, is only the short version. Let’s take a look at the coffee plant, its main varieties, and how to spot a good bean for your morning brew.

Types of coffee

Coffee plants (genus Coffea) are small trees or shrubs native to the tropical areas of Africa and Asia, as well as southern Africa. They can grow up to 3–3.5 m (9.8–11.5 ft) in height at the tropics.

While there are many different types of coffee out there (over 120 known species, here’s a list of some well-known ones), the two most of us have ever tasted are Coffea arabica (commonly known simply as “Arabica”) and Coffea canephora (known as “Robusta”). Arabica plants account for 60-80% of the world’s coffee production, while Robusta accounts for about 20-40%.

Most types of coffee plants grow better at higher altitude but will be killed by freezing temperatures. A bush of Arabica coffee takes 3-5 years to mature into growing fruits and can keep producing for an average of between 50 to 60 years.

Ripening coffee fruits.
Image credits Miloslav Hamřík.

Around 5-10% of all coffee fruits bear a single bean rather than a pair of them. The pits from these fruits, known as peaberries, are handled and sold separately from the regular, flat-faced coffee beans we know and love. Common wisdom holds that these peaberries are more flavorful than regular beans as they’re believed to roast more uniformly.

On average, it takes 5-8 pounds of harvested coffee cherries to eventually yield 1 pound of high-quality coffee beans.

Types of coffees

Between the two varieties, Robusta tends to have a more bitter taste. It’s a bit easier (and thus cheaper) to grow so all in all, it’s considered to be the lower quality variety. It’s much more disease resistant and has a higher yield than Arabica and is more tolerant of environmental conditions (which gave it its name).

Image via Pixabay.

Because of its more bitter taste, Robusta is generally not used for espresso blends, although some producers do mix it in as it helps better accentuate the product’s taste and aroma. More run-of-the-mill products like regular and instant coffee, however, make heavy use of this variety, which is good news for morning-you: Robusta has a higher caffeine content.

Arabica is more difficult to grow as this variety is more sensitive to location (it needs high-altitude, tropical climates) and soil (ideally, volcanic). Subtropical regions in the 16-24 degree latitude range, and equatorial regions with latitudes less than 10 degrees make for ideal growing spots for Arabica. Arabica grown at higher elevations takes more to grow but produces a more flavorful bean.

Coffee is acidic — this gives it its particular flavor and taste. Different varieties of coffee have different levels of acidity, which is why we differentiate between them commercially. Acidity is mostly impacted by growing altitude and soil: as a rule of thumb, beans produced in Africa tend to have higher acidity and fruity or floral undertones, while coffee from Brazil or Sumatra tends to have a much lower acidity with cocoa and nutty notes.

Image via Pixabay.

Higher-quality coffee tends to come from a single crop, which helps preserve its taste and flavor (somewhat like a single malt whiskey), while cheaper options tend to use blends (giving it a more ‘regular’ but balanced taste). Single-origin coffee tends to be more expensive but also more varied in regards to aroma, taste, and caffeine content. Blends are used to make the most of different types of coffee beans and counteract their individual weaknesses: a roaster might blend a coffee with a full body with another coffee that has a striking taste to support each other for example.

Bitterness in coffee is the result of the brewing process. If the beans are ground too finely, or they’re over-brewed, the drink will have a bitter and harsh aroma. This happens because too many flavorful compounds are extracted from the beans thanks to more contact between the water and the grounds (if the particles are too small) or over-brewing.

So, if you wake up to bitter coffee tomorrow, try brewing it less.


Heavy coffee drinkers can smell its aroma much easier than other people — and it seems tied to craving

Regular coffee drinkers can perceive the smell of coffee with surprising alacrity, a new study reports. Compared to non-coffee drinkers, they’re also faster at recognizing the aroma, it adds.


Image credits Karolina Grabowska.

Those who make a habit out of drinking coffee are more sensitive to its odor and are faster to identify its aroma. Additionally, their ability to sniff out the bean also increases the more they crave coffee. This study, its authors write, provides the first evidence that coffee addicts are more sensitive to the smell of coffee than the rest of us. While the team worked with coffee, their findings should be broadly applicable to other substances with a distinct smell — for example, the findings could help design new aversion therapies for people addicted to tobacco or cannabis in addition to coffee.

Brewed to perfection

“We found the higher the caffeine use, the quicker a person recognised the odour of coffee,” says Dr. Lorenzo Stafford, an olfactory expert in the Department of Psychology at the University of Portsmouth, and lead author of the paper.

“We also found that those higher caffeine users were able to detect the odour of a heavily diluted coffee chemical at much lower concentrations, and this ability increased with their level of craving. So, the more they desired caffeine, the better their sense of smell for coffee.”

The team explains that drug cues (such as the smell of an alcoholic beverage) can trigger cravings in users. However, the team wanted to check if the relationship works the other way around: whether or not people who are big coffee drinkers can more readily perceive and respond to the smell of coffee. Their study is the first to show that this is true, at least with mildly-addictive drugs such as coffee. The more we want that cup of warm goodness, the better we are at sniffing it out wherever it may hide. The results suggest heavy coffee drinkers were more sensitive to the smell of coffee, and that the smell is linked to their cravings.

“Caffeine is the most widely consumed psychoactive drug and these findings suggest that changes in the ability to detect smells could be a useful index of drug dependency,” Stafford says.

The study was based on two experiments. In the first one, 62 men and women were divided into three groups: those who never drank anything with caffeine, and those who consumed some (70-250mg, equivalent to 1-3.5 cups of instant coffee a day), and those who consumed a high amount (300mg, equivalent to 4 or more cups of instant coffee a day).

Each participant was blindfolded and asked to pick out traces of coffee odor from odor blanks (a substrate with no smell). For this test, participants were asked to identify the scent of real coffee as quickly as possible. As a control test, participants were also asked to perform the same task with essential lavender oil.

Those in the heavy coffee drinker group were able to correctly identify the smell of coffee at weaker concentrations than their peers and were faster to do so.

“More interestingly, higher craving, specifically that which measured the ability of caffeine to reverse withdrawal symptoms such as fatigue, was related to greater sensitivity in the odour detection test,” Dr. Stafford said.

In the second test, 32 people (not involved in the first experiment) were divided into two — one coffee-drinker, one non-coffee-drinker — groups. They were put through the same odor detection test for coffee, this time with the control involving non-food odors. Here, too, coffee consumers were more sensitive to the coffee smell, but not to the non-food odors.

Overall, the findings suggest that our sensitivity to particular smells is linked to cravings and that this could be used to break some drug use behaviors. Previous research has shown that training people to associate an odor with something unpleasant showed greater discrimination to that odor, which could be used to help them steer clear of certain substances.

The paper “Higher olfactory sensitivity to coffee odour in habitual caffeine users” has been published in the journal Experimental and Clinical Psychopharmacology.

espresso coffee

How to brew the perfect espresso with chemistry

espresso coffee

Credit: Pixabay.

Scientists at the University of Oregon have studied every single variable they could think of in order to achieve the ultimate, reproducibly delicious espresso. Based on physical measurements and experimental extraction kinetics, the researchers applied a numerical approach that helped them figure out what it takes to brew the perfect shot of espresso. This is the so-called ‘God Shot’ — the espresso that extracts the most flavor and wastes the least amount of coffee.

The team of researchers was led by Dr. Christopher Hendon, a computational chemist at the University of Oregon, whose previous work earned him the title “Dr. Coffee.” Unlike other researchers, Hendon doesn’t actually work with chemicals directly (apart from water and ground coffee). Instead, he and colleagues use powerful computers to solve quantum mechanical problems, enabling them to learn new insights that otherwise wouldn’t have been attainable.

The God Shot

You might have brewed yourself a delicious cup of espresso yesterday only to find that today’s cup had a different flavor. You did everything exactly the same, so why does this happen? This is something even the world’s best baristas struggle with, a puzzle that inspired Hendon to delve really deeply into all the variables that impact an espresso’s reproducibility. Basically, what he found out is that in order to make an espresso taste the same each time, you need to pay attention to the kind of water you use, the storage of the coffee, the particle size of the ground coffee, and the coffee itself.

Dr. Christopher Hendon. Credit: University of Oregon.

Dr. Christopher Hendon. Credit: University of Oregon.

Depending on where you live, water will always differ in terms of hardness, and this will have an effect on flavor. For instance, harder water, which has a higher concentration of magnesium and calcium, will cause the coffee to have a stronger flavor than a softer kind of water. That’s because the magnesium in the water binds to coffee’s flavor compounds, then releases them into your brew. Meanwhile, other compounds found in water, like bicarbonate, can give the coffee a more bitter flavor.

Another important variable is the freshness of the coffee beans. Freshly roasted coffee can fill the whole room with dazzling flavors — but that doesn’t last long. That’s because the roasted coffee contains compounds that easily evaporate and escape. You can delay the escape of the volatile compounds by storing the coffee at a lower temperature. Many baristas store their coffee in a fridge, and for good reason.

“The main challenge with my work is that any studies performed on coffee are extremely time sensitive.  The coffee itself “ages” or stales, which means that the extractions are affected and the sample reproducibility is minimized. We overcame this by cooling the coffee to liquid nitrogen temperatures,” Hendon told ZME Science.

Grinding coffee to the right particle size is another important step worth considering. Smaller coffee particles offer a greater surface area for the water to interact with chemically, improving the extraction process and, consequently, the flavor of the espresso — but only to a point, Hendon warns. Past a critical point, smaller isn’t better. When the coffee particles and hot water interact, they ideally should do so uniformly.

“The true ‘aha!’ moment came when we developed a mathematical model to demonstrate that you can theoretically extract all of the “tasty” coffee in an espresso type extractors in less than 10 seconds.  This was in contrast to the belief in that espresso needs 25-35 second shot time,” Hendon said.

Working closely with baristas, Hendon has worked out an optimized process that systematically maximizes the extraction of the coffee — and such work could save the industry billions.

“By predetermining the coffee-to-water ratio, as well as the water pressure, the maximum extraction can be systematically determined,” he said in a statement. “The barista can then iteratively improve their espresso reproducibility, while reducing waste coffee mass.”

By his calculations, Hendon claims that due to inhomogeneous extraction, about 40% of the espresso puck is wasted, not to mention the negative impact to the flavor. In the U.S. alone, the coffee industry amounts to a $40 billion business.

So, what can you do to brew a better espresso consistently at home? In short: buy fresh beans, preferably locally, use 15 grams of freshly ground coffee for every cup of water, and heat water to 93°C (200°F).

“Given coffee is amorphous, there is no single coffee grinder that can produce a perfectly uniform particle size distribution. The best thing a home user can do without investing a lot of money into equipment is two-fold: 1) buy higher quality coffee (it has fewer defects and in principle has more reproducible flavor), 2) use a scale to measure the mass of coffee and water used in the brewing.  If the ratios are maintained, then you are already a lot closer to reproducibility,” Hendon told ZME Science.

Next, Hendon and colleagues “plan on tackling the production of energy compounds from coffee waste.”

“The most important thing in coffee is that you, the consumer, identifies what you like to taste and then are able to reproduce it consistently,” Hendon said.

The researchers presented their findings on Wednesday at the 255th National Meeting & Exposition of the American Chemical Society (ACS). 

Caffeine solar cell.

Researchers figure out how coffee can boost (some) solar cells

Researchers at the University of California, Los Angeles (UCLA) and Solargiga Energy in China have tried to perk up solar panels with coffee. It worked.

Caffeine solar cell.

One of the solar cells the team made using the new method.
Image credits Rui Wang and Jingjing Xue.

The team reports that caffeine can help improve the efficiency with which perovskite solar panels convert light to electricity. The finding could help them a more competitive and cost-effective alternative to silicon solar cells.

Wakey, wakey

“One day, as we were discussing perovskite solar cells, our colleague Rui Wang said, ‘If we need coffee to boost our energy then what about perovskites? Would they need coffee to perform better?'” recalls Jingjing Xue, a Ph.D. candidate at the Department of Materials Science and Engineering at UCLA and co-lead author of the study.

After, presumably, a few rounds of hearty laughs, the team set their cups down and set to work on trying to see if the idea has any value.

The authors have previously worked on improving the thermal stability of perovskite materials — the blue compounds with a particular crystal structure that forms the light-harvesting layer certain solar cells — to make them more efficient at harvesting sunlight. Part of that work involved trying to strengthen the material with additives such as dimethyl sulfoxide, an approach which showed some success in the short term, but wasn’t stable over longer spans of time. Caffeine, however, is an alkaloid compound whose molecular structures could, the team suspected based on their previous experience, interact with the precursors used to make perovskite materials.

So, they set out to add caffeine to the perovskite layer of forty solar cells and used infrared spectroscopy, an approach that uses infrared radiation to identify a sample’s chemical components, to determine if the materials bonded. They had.

Further infrared spectroscopy tests showed that carbonyl groups (a carbon atom double bonded to an oxygen) in caffeine tied to lead ions in the perovskite layer to form a “molecular lock”. This lock increases the minimum amount of energy needed for the perovskite layer to react to sunlight, boosting the solar cell efficiency from 17% to over 20%. This lock stood firm when the material was heated, which suggests that caffeine could also help to make the solar cells more thermally-stable.

“We were surprised by the results,” says Wang, who is also a Ph.D. candidate in Yang’s research group at UCLA. “During our first try incorporating caffeine, our perovskite solar cells already reached almost the highest efficiency we achieved in the paper.”

The caveat, or caffeat if you so prefer, is that this approach likely won’t work with other types of solar cells. It only works here because it can tie into the unique molecular structure of perovskite precursors. However, it may be enough to give this type of solar cell variety an edge on the market.

Currently, perovskite solar cells are the cheaper and more flexible option available on the market. They’re also easier to manufacture, as they can be fabricated from liquid precursors — their silicon counterparts are cast from solid crystal ingots. Wang believes that caffeine might make them even easier to fabricate on a large scale, in addition to making them more efficient.

“Caffeine can help the perovskite achieve high crystallinity, low defects, and good stability,” he says. “This means it can potentially play a role in the scalable production of perovskite solar cells.”

The team plans to continue their efforts by investigating the chemical structure of the caffeine-infused perovskite crystals and identify what materials would best serve as a protective layer for the solar cells.

The paper “Caffeine Improves the Performance and Thermal Stability of Perovskite Solar Cells” has been published in the journal Joule.

Coffee not essential for life, Switzerland decides

Switzerland has just made a jaw-dropping announcement: it no longer considers coffee essential for life. For the first time since WWII, it will stop stockpiling it.

The decision was made as part of a periodic reassessment of which vital goods to stockpile for emergency situations such as wars and national disaster — and must have generated quite a few nervous twitches.

“The National Economic Supply has checked the maintenance of today’s compulsory storage of coffee,” a statement explains.

“Coffee is not vital according to the criteria that apply today. That is, coffee contains almost no calories and therefore does not make any contribution to food security from a nutritional point of view.”

Switzerland takes its national emergencies very seriously. Military conscription is mandatory for all able-bodied male citizens, and the country has a continuous stockpile of emergency foods — a club into which, it seems, coffee is not invited anymore.

There are currently 15,300 tonnes of stockpiled coffee in Switzerland, with the stock being maintained by 15 companies, including Nestle. Switzerland’s 8.5 million residents consume around 9kg (20lb) of coffee per person annually —  doubling the average US consumption of 4.5 kg per capita. This means that at current consumption rates, the stock would last for about six months.

It’s a significant cost to purchase and maintain the coffee stock and, indeed, while research suggests some benefits to drinking coffee, it’s hardly an essential substance for life — despite what your caffeine-oholic friends might claim. In that sense, the decision makes perfect sense.

“The department notes that coffee contains virtually no energy,” an explanatory report on the decision states, indicating that there are no macronutrients such as proteins, fats, and digestible carbohydrates in coffee.

However, it still made a lot of people angry, including officials from Réservesuisse, the Bern-based organisation that oversees Switzerland’s food stockpiles.

Réservesuisse asked the Federal Office to reconsider its recommendation, and an official decision will be made in November.

Even if the coffee stockpiling is stopped, there’s still good news for Swiss coffee drinkers. The country finances its coffee stockpile through a coffee tax — which would be eliminated if the stockpiling is stopped. In other words, coffee will get cheaper if it stops being stockpiled.


Tired? Try looking at a cup of coffee — new research says that’s enough to perk you up

Even hints of coffee can change the pace of our minds, making us more alert and attentive.


Image via Pixabay.

We’ve come to associate coffee with productivity to such an extent — at least in Western cultures — that even hints of it have an effect on how our minds work. The findings are part of a new study published by researchers from the University of Toronto (U of T).

Hints of productivity

“Coffee is one of the most popular beverages and a lot is known about its physical effects,” said Sam Maglio, an associate professor in the department of management at U of T Scarborough and the study’s co-author.

“Much less is known about its psychological meaning — in other words, how even seeing reminders of it can influence how we think.”

Together with Eugene Chan, a former PhD student at Rotman, Maglio looked at a psychological effect called priming. Through priming, they explain, exposure to even subtle cues or stimuli can alter how we perceive the world around us, our thoughts, and our behavior.

As we tend to encounter coffee-related cues pretty often in our daily lives, or think about the brew ourselves, we tend to undergo this priming process regarding coffee quite a lot. The authors wanted to see if this actually has a noticeable effect on people — specifically, they wanted to see if “there was an association between coffee and arousal such that if we simply exposed people to coffee-related cues, their physiological arousal would increase, as it would if they had actually drank coffee,” according to Maglio.

Arousal refers to the state of being alert, awake, and attentive. In the brain, arousal is mediated by specific brain areas increasing and then maintaining their levels of activity. Psychological arousal can be triggered by many things, the authors explain, including emotions, neurotransmitters in the brain, or the caffeine we consume (that’s why coffee wakes you up). But does looking at a caffeinated drink, or thinking about one, have the same effect on us?

In order to find out, the team carried out four separate studies, working with a mix of participants from western and eastern cultures alike. The wide cultural range of the participants was needed so that the team could compare the effects of both coffee- and tea-related cues. They found that participants exposed to coffee-related cues perceived time as shorter and thought in more concrete, precise terms.

“People who experience physiological arousal — again, in this case as the result of priming and not drinking coffee itself — see the world in more specific, detailed terms,” says Maglio. “This has a number of implications for how people process information and make judgments and decisions.”

This effect was relatively strong in western participants, but not so pronounced in participants who grew up in eastern cultures. The team believes this is due to differences in how coffee is perceived among the two cultural groups.

“In North America we have this image of a prototypical executive rushing off to an important meeting with a triple espresso in their hand,” Maglio explains, adding that “there’s this connection between drinking caffeine and arousal that may not exist in other cultures.”

In the future, the authors plan to continue this line of research and look at the associations people have for different foods and beverages — and how that influences their psychological priming effects.

The paper “Coffee cues elevate arousal and reduce level of construal” has been published in the journal Consciousness and Cognition.


Is Coffee good or bad? A critical view on the science behind it


Credit: Pixabay.

Coffee is a beloved drink (or fuel) for millions of people around the world. It’s also one of the most well-studied beverages in the world — so much so that it can be extremely confusing to navigate its scientific literature. It seems like every day there’s a new study on coffee’s health benefits but also, conversely, its downsides. Which begs the question: is coffee good or bad?

The black fuel that sends your metabolism into overdrive

Caffeine (1,3,7-trimethylxanthine), the main stimulant found in coffee — but also in tea, soft drinks, chocolate, and some nuts — has many metabolic effects. Besides caffeine, coffee contains other substances with important metabolic effects such as theobromine (main stimulant found in cocoas), theophylline (may be good for treating asthma), and chlorogenic acid (may slow down carbohydrate absorption).

One of the most familiar feelings people associate with coffee is “awakeness” — after all, so many people use coffee on a daily basis in their morning routines. Within 15 minutes of the first sip, caffeine is known to boost mental alertness and cognitive functioning, as well as enhancing physical performance by improving endurance and reaction time.

It does so by latching onto and blocking receptors in the brain for adenosine, a chemical which is produced by neurons throughout the day. When adenosine levels are high, the body’s metabolism slows down, priming you for sleep. With adenosine out of the way, the neurotransmitters dopamine and glutamate, which are natural stimulants generated in the brain, are free to do their magic. You start feeling more alert and awake, as a consequence.

But, as every coffee ‘addict’ knows, this effect lessens over time because of an annoying thing called tolerance. So you’ll need to do intake more and more caffeine to achieve the same level of stimulation from dopamine and glutamate.

What caffeine does to the body

While stimulating the nervous system, caffeine also signals fat cells to break down, releasing fatty acids in the bloodstream. This also means that the body has more glycogen available in the muscles to burn during a workout, enhancing endurance. In the same vein, caffeine has been found to influence the energy balance by increasing energy expenditure and decreasing energy intake, hence it can be a weight regulator for some people. It’s no surprise that caffeine is often found in weight loss products. Counter-intuitively, the increase in metabolism is less pronounced for obese individuals. One study, for instance, found that caffeine increased lipid oxidation by as much as 29% in lean women, while the increase was only about 10% in obese women. Again, the effects may be less pronounced in regular coffee consumers and decline with age. If the main reason you’re using coffee is for weight loss, you might want to alternate your patterns of consumption — for instance, use coffee for two weeks, stop for the next two weeks to prevent tolerance, and then reset.

Some studies show that drinking three or four cups of coffee a day could reduce your risk of developing type 2 diabetes by 25% compared to consuming no coffee or less than two cups daily. Caffeinated coffee may improve glycaemic metabolism by reducing the glucose curve and increasing the insulin response. But before you hurry to the supermarket to buy all the coffee on the shelves, bear in mind that there is a lot of conflicting information about coffee.

A 2017 study found five out the seven studies it analyzed concluded that caffeine intake increases blood glucose levels, and prolongs the period of high blood glucose levels in individuals with diabetes. Another study found that acute caffeine consumption in healthy individuals significantly decreased insulin sensitivity, potentially leading to high blood sugar. So drinking a lot of coffee (more than seven cups/day) may actually cause you to put on more weight and increase the risk of developing diabetes.

An old idea is that you shouldn’t drink coffee if you have heart problems, but the opposite may be true. Drinking around four cups of coffee every day promotes the movement of a regulatory protein into mitochondria, which may prevent cardiovascular and cellular damage. An earlier report, published in 2017 in the journal Annual Review of Nutrition, analyzed the results of more than 100 coffee and caffeine studies, finding that coffee was associated with a probable decreased risk of cardiovascular disease.

What’s less ambiguous is that coffee is the most widely used dietary source of antioxidants in the world. Antioxidants are important because they pair with so-called “free radicals”, which are molecules with unpaired electrons that can damage cells and DNA. Among the many antioxidants found in coffee, the most effective are hydrocinnamic acids and polyphenols. This antioxidation effect is thought to protect the body against aging and many diseases that are partly caused by oxidative stress, including liver disease, Parkinson’s, various types of inflammation, and even cancer.

Effects can vary from person to person, hence the conflicting information

Credit: Pixabay.

Credit: Pixabay.

Conflicting information about the effects of coffee abound. Until not too long ago, the World Health Organization classified coffee as “possibly” carcinogenic, but later reversed the statement stating that evidence for the association between coffee and cancer is inadequate. As mentioned earlier, the same conflicting evidence can be seen for cardiovascular disease. Perhaps the reason so many studies come up with so many different conclusions is that every person is different to a degree, especially in the way they metabolize substances.

According to researchers at the University of Toronto, one particular gene may have an important say in the matter. The gene identified by the researchers, called YP1A2, controls an enzyme that determines how quickly our bodies break down caffeine. Individuals who have a certain variant of the gene can metabolize caffeine four times faster than people who inherit one or more copies of the slow variant of the gene. Previously, the same team of researchers led by Ahmed El-Sohemy, a professor in the department of nutritional sciences at the University of Toronto, had studied 4,000 adults, including about 2,000 who had previously had a heart attack. The results suggested that ingesting four or more cups of coffee per day was associated with a 36% increased risk of a heart attack. However, when the participants were split into groups (fast metabolizers and slow metabolizers), the authors found that acute coffee intake was associated with increased heart attack risk only in the slow metabolizer group.

Slow metabolizers keep caffeine in their system for longer, offering it more time to trigger harmful effects such as heart attacks. On the other hand, fast metabolizers may allow antioxidants, polyphenols and coffee’s other healthful compounds to kick in without the side effects of caffeine because the stimulant is flushed out of the system fast.

And in all likelihood, there may be many other genetic and environmental factors contributing to differences in caffeine metabolism.

Coffee seems to do more good than harm

Many studies that investigate the health outcomes of caffeine can use different methodologies, demographics, or can simply be flawed. Overall, however, studies seem to point to net benefits of drinking coffee — although how fast you metabolize the stimulant seems to play a key role. An umbrella review published in the prestigious British Medical Journal — which included more than 200 meta-analyses of observational and interventional studies of coffee consumption and any health outcome — found that “coffee consumption was more often associated with benefit than harm.” Three to four cups of coffee reduced the risk of type 2 diabetes, metabolic syndrome, kidney stones, gout, and several types of cancer, including endometrial, skin, prostate and liver cancer. The only vulnerable group which the authors identified was pregnant women, who are at an increased risk of bone fracture.

“Coffee consumption seems generally safe within usual levels of intake, with summary estimates indicating largest risk reduction for various health outcomes at three to four cups a day, and more likely to benefit health than harm,” the researchers concluded.

Some die-hard fans might consider what I’m about to say next as heresy, but there is such a thing as too much coffee. In fact, you can even overdose (and risk dying) from too much caffeine — although that would be quite challenging to do on coffee alone. If you weigh 60 kg, you’d need to drink around 55 cups of coffee to overdose — but be aware that energy drinks have a high concentration of caffeine which makes it easy to overdose if you use them in quick succession. According to one study, there have been only 45 deaths related to caffeine reported between 1959 and 2010.

You don’t have to overdose to feel unpleasant side effects. Going above 400 mg daily, the recommended dose for adults, can cause jitteriness, insomnia, and irritability. So, moderation is key — just like with everything else in life. And if you actually decide to take a break, be prepared to face withdrawal symptoms such as feeling anxious, irritable, and drowsy. Luckily, these side effects are temporary and fade within 3 to 10 days.

Bottom line: evidence points to the fact that coffee does more good than harm, indicating that it can be part of a healthful diet.

[NOW READ] How to brew the perfect espresso with chemistry


Coffee beans.

Over half of the world’s wild coffee faces extinction, new research finds

Climate change, disease, and deforestation are pushing wild coffee species to the brink of extinction.

Coffee beans.

Image credits: Michal Jarmoluk.

Researchers from the Royal Botanical Gardens, Kew, in the UK, say that nearly 60% of the 124 known species of wild coffee are at risk of extinction. Some areas of the world are particularly disheartening for the beloved beans — over 71% of wild coffee species found in Madagascar and the Indian Ocean, for instance, are threatened.

It’s bean a pleasure

“As a coffee drinker you don’t need to worry in the short term,” lead author Aaron Davis, head of coffee research and plant resources at Kew, told AFP.

“What we are saying is that in the long term if we don’t act now to preserve those key resources we don’t have a very bright future for coffee farming.”

Davis and his team focused their research on Ethiopia. People in this country, along with South Sudan, have been harvesting arabica (Coffea arabica) for millennia, and have also been cultivating it for centuries. Today, arabica makes up around 60% to 70% of all coffee sales worldwide, with robusta (C. canephora) filling up the rest.

The team used computer modeling techniques to analyze climate data for Ethiopia over the last four decades. Working with these models, they were able to measure how quickly deforestation, drought, and disease are eroding coffee’s natural habitat. All in all, they report, 75 coffee species are threatened with extinction. Of that number, 13 species have been classed as critically endangered, 40 as endangered, and 22 as vulnerable.

“Overall, the fact that the extinction risk across all coffee species was so high – nearly 60 percent – that’s way above normal extinction risk figures for plants,” Davis explains.

“It’s up there with the most endangered plant groups.”

While those 75 species don’t make it into your cup every morning, they are an important buffer. Genetic diversity is a crucial ingredient for a species’ survival in nature. Furthermore, wild plant variations act as a vital repository of genes that farmers can draw on to buttress their crops. This practice can be traced back several centuries in the case of Ethiopian arabica coffee, the team explains.

Given the sensitivity of this plant to climate change, disease, and pests, we will probably need to draw on this technique once again.

Still, not all is lost. The team says that if we act quickly enough to expand and protect the plant’s natural habitat, we should be able to keep these wild species of coffee around.

“Many protected areas fail to conserve the diversity encompassed within their borders, and workable management plans would be required to ensure that target species are effectively conserved,” the authors write.

We’re not facing a shortage of coffee right now, but scarcity is quite possible in the near future. A report commissioned by Fairtrade Australia & New Zealand in 2016 predicted that in the near future, coffee production could fall by as much as 50% due to climatic changes.

The paper “High extinction risk for wild coffee species and implications for coffee sector sustainability” has been published in the journal Science Advances.

Coffee or tea? The answer might lie in your genes

It’s a heated debate, with passionate people on both sides, but scientists might bring an unexpected player to the argument table: genetics.

Over 2.25 billion cups of coffee are consumed in the world every day, and tea is no slouch either, with 1.42 million pounds of tea consumed by Americans every single day — and Americans lag strongly behind other countries, particularly India and China. Yet, while both beverages seem very popular among their consumer groups (which sometimes overlap), there’s often a strong disagreement between the two camps. While there’s obviously a strong cultural component to personal preference, genetics might also play a role. Essentially, whether someone is a coffee drinker or a tea drinker might be linked with the presence or absence of key genes that shape how bitter flavors taste.

If you think about it, enjoying bitter things (like coffee) seems a bit illogical. After all, the main function of the bitter flavor is to send out a signal that there might be some harmful substances involved — so why do we like it?

According to the new study, people who like coffee are more sensitive to the bitter taste, which seems counterintuitive, but researchers say this happens because coffee-drinkers associate the bitter taste with the follow-up reward of stimulation that coffee brings.

“You’d expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee,” said Marilyn Cornelis, assistant professor of preventive medicine at Northwestern University Feinberg School of Medicine. “The opposite results of our study suggest coffee consumers acquire a taste or an ability to detect caffeine due to the learned positive reinforcement (i.e. stimulation) elicited by caffeine.”

Both coffee and tea (at least some types of tea) contain bitter-tasting caffeine, but coffee contains another bitter molecule: quinine, commonly found in tonic water. Different bitter molecules are linked to different taste receptor genes, and Cornelis and colleagues at the University of Queensland in Australia wanted to study the connection between these taste genes and coffee consumption.

They analyzed data on 430,000 men and women aged 37-73 in the UK, finding that people with gene variants that make them taste caffeine more strongly were 20% more likely to be heavy coffee drinkers (drinking more than 4 cups per day).

A similar correlation was reported for heavy tea drinkers.

“As caffeine contributes to not only the bitterness of coffee but also its perceived strength and texture, people who are better at detecting caffeine may find coffee more enjoyable and flavourful,” says Daniel Liang-Dar Hwang, one of the study authors. “In contrast, people who carried the bitter taste receptors for quinine or PROP drank less coffee and more tea. Compared to the average person, every extra copy of the quinine or PROP receptor gene was linked with a 9% or 4% higher chance of being a heavy tea drinker (>5 cups of tea a day).”

So, which one do you like — coffee or tea?

The study was published in Scientific Reports. DOI: 10.1038/s41598-018-34713-z

Severe symptoms of leaf rust. Credit: Wikimedia Commons.

‘Rust’ fungi threaten to wipe out Latin America’s coffee crops

Severe symptoms of leaf rust. Credit: Wikimedia Commons.

Severe symptoms of leaf rust. Credit: Wikimedia Commons.

As the third most consumed beverage in the world, after water and tea, coffee beans are in high demand everywhere. Second only to oil, coffee is among the world’s most traded commodities, with about half a trillion cups consumed per year. However, a pestilent fungus for which there is no cure is threatening to decimate coffee crops throughout South and Central America, which accounts for most of the world’s production of tasty Arabica beans.

The biggest coffee crisis in 150 years

The disease, known as coffee leaf rust, is caused by the fungus Hemileia vastatrix. When its spores — which can survive for months and travel airborne — come into contact with the coffee plant’s leaves, they germinate and penetrate that leaf within hours.

The first observable symptoms are small, pale yellow spots on the upper surfaces of the leaves. As these spots gradually increase in diameter, masses of orange urediniospores appear on the undersurfaces.

Eventually, the leaves start falling off, reducing the amount of essential nutrients that the plant receives. The disease does not outright kill the plant but it drops its yield to feeble levels, essentially choking the coffee plant.

It’s the same disease that was responsible for the famous coffee crash in Sri Lanka (formerly known as Ceylon) in the mid-1800s. Sri Lanka was once the leading coffee producer in the world, responsible for exporting over 100 million pounds annually of the commodity. Within a decade after the first signs of the diseases hit the island, exports fell by 80%. Two decades later, exports were down 90% relative to levels recorded before the outbreak.

The fungus later appeared in coffee farms across Africa, decimating plantations, but somehow wasn’t able to infect Latin America which, today, produces seven-eights of the world’s Arabica coffee — until the 1970s, when it first appeared in Brazil, sowing panic among coffee farmers and trade organizations. As NPR reports, coffee leaf rust steadily spread throughout the continent, despite farmers’ best efforts to stave off the diseases through measures like replanting or the use of genetically-modified breeds that have more resistance to the fungus. 

The last decade has been particularly merciless. In Central America, 70% of Arabica farms have been hit by the disease, resulting in $3.2 billion in damage and 1.7 million lost jobs.

Although scientists have been aware of H. vastatrix for more than a century, the fungus is still poorly understood, so there is no cure or meaningful way to help farmers prevent the rust. The challenge lies in the fact that rust fungi are obligate parasites — which must also infect a host in order to survive, spread, and fulfill their lifecycle — so it is difficult to get ahold of pure DNA. This also means that you can’t grow the fungi in culture or manipulate them in the lab. What’s more, these are microfungi — small organisms embedded in their hosts, which are challenging to study.

But that doesn’t mean that scientists aren’t tackling the challenge. Work is now underway in order to understand the rust fungi’s reproductive processes and to sequence its full genome. In the meantime, coffee farmers will have to brave the situation with whatever little resources they have left. And, as if rust fungi weren’t enough, farmers have another huge threat looming over their livelihoods — climate change. According to a 2017 study, “coffee-suitable areas will be reduced by 73–88% by 2050 across warming scenarios, a decline 46–76% greater than estimated by global assessments.”