Tag Archives: stroke

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.

Fried food can promote poor cardiovascular health, heart disease, stroke

Fried food tastes good, but it’s not very healthy for you. A new metastudy reports that consumption of such food is linked to an increased risk of major heart disease and stroke.

Most of us today make an effort to not eat only fast food and take-out, which is admirable, but that doesn’t make our diets ‘healthy’ per se. Western dietary habits are known to promote poor cardiovascular health, the authors note, but it was still unknown how much fried food specifically contributed to this. In order to get a better idea of the effect such food has on our cardiovascular health, a team of Chinese researchers has reviewed past research on this subject.

Don’t fry

The team reviewed 17 studies involving 62,445 participants and 36,727 major cardiovascular events (such as a heart attack or stroke). They also pooled in data from a further 6 which tracked their patients over a long timeframe (9.5 years on average), involving 54,873 participants and 85,906 deaths. Put together, the data was meant to help us gauge how damaging fried food is to our cardiovascular health, and how much they increase our risk of death from cardiovascular disease.

The results show that participants in the group who consumed the most fried food had a 28% higher chance of experiencing a cardiovascular (CVS) event than those who consumed the least. They also had a 22% higher risk of coronary heart disease and a 37% higher risk of heart failure.

Even when the team controlled for various factors and participant characteristics, the link between the consumption of fried food and major cardiovascular events, coronary heart disease, and heart failure remained. The risk increased with each additional 114 g weekly serving by 3%, 2%, and 12%, respectively, the authors report.

Still, the findings aren’t necessarily conclusive. Some of the studies only tracked one type of fried food, for example fried fish or potatoes, not participants’ total intake. Furthermore, every study was designed differently and all relied on information the participants were asked to remember (which is unreliable). The team explains that all these elements could mean the studies “underestimated” the association between these and cardiovascular health. They also note that such factors need to be taken into account when interpreting the results.

Exactly how fried foods can influence the development of cardiovascular disease is still unclear, but the team has some possible explanations. First off, fatty foods are very energy-dense but the vegetable oil they contain gets broken down into trans fatty acids inside our bodies, which is harmful. Frying also generates a host of byproducts involved in inflammatory processes, and fried food is often very salty (an excess of salt is also bad for you).

The paper “Fried-food consumption and risk of cardiovascular disease and all-cause mortality: a meta-analysis of observational studies” has been published in the journal BMJ.

What is a stroke?

The human body is a wonderful and complicated device. This lets us do all kinds of awesome things, like seeing, thinking about, or tasting ice cream. But its complexity also leaves it vulnerable to damage. One of the ways that damage can manifest itself is as a stroke, a leading cause of mortality and disability across the world.

Image credits Gordon Johnson.

Although its effects are significant, a stroke is actually a very small event. So let’s take a look at exactly what they are, why they happen, and why they’re so bad for us.

Bad blockage

In essence, a stroke takes place when blood can’t properly reach part of the brain. One example would be blood vessels becoming clogged — typically due to a blood clot, but not necessarily. This cuts off the blood supply to a part of the brain, meaning neurons there don’t receive nutrients or, much worse, oxygen. Affected areas of the brain will thus quickly stop functioning, leading to a loss of control over the body parts or processes the area governs. Unless addressed quickly, strokes can lead to permanent damage in the affected areas, including tissue death.

Both internal and external factors can help cause a stroke. Sustained high acceleration rates (typically measured in “g”-s, the “acceleration of gravity”) can lead to a stroke, as can high blood pressure. They are also known as cerebrovascular accidents (‘CVA’) or less commonly as ‘brain attacks’.

In very broad lines, there are two types of strokes: ischemic, where blood flow is cut to a part of the brain by a clot, for example, and hemorrhagic, where blood doesn’t reach the areas it’s supposed to due to bleeding within the brain. Either way, it’s not good news.

What to look out for

Please keep in mind that strokes are not a harmless event. They are a medical emergency in the full sense of the phrase, and a fast reaction can help save the patient’s life. After symptoms set in, there’s a window of around 3 to 4-and-a-half hours for doctors to resolve the issue. Even so, brain tissue degrades very rapidly when deprived of oxygen, and a quick response is meant to prevent extensive damage but can’t avoid all damage. Typically, strokes lead to long-lasting brain damage that can seriously impair a person’s ability to function. The effects of such an event can range from (relatively) mild, such as general numbness in an area, to quite serious, such as losing the ability to speak or walk.

Image credits New York Department of Health.

But, as I mentioned, a FAST response can help you spot the early warning signs of a stroke and help protect your loved ones. The National Stroke Association (NSA) defines FAST as:

  • Face: watch for irregularities in the movements of facial muscles. A droopy face or sagging smile can be an important clue that something is not quite right in the brain.
  • Arms: ask the person in question to raise both arms. Strokes affect brain activity, which can cascade into effects on muscle groups. If one or both of the individual’s arms move or drift downwards against their wishes, a stroke might be the cause.
  • Speech: impaired muscle control can also reveal itself in slurry, messy speech. Ask the person in question to repeat a simple phrase and determine if they are able to do so.
  • Time: as we’ve said before, the secret of success here is moving FAST. If a person has any, several, or all of these symptoms, call emergency services (i.e. 911 in the U.S.) immediately. It is quite literally a matter of life or death.

Treatment generally consists of anti-clotting medication (thrombolytics), but will obviously differ based on the cause of the stroke. Giving anti-clotting medication to someone with a hemorrhagic CVA is a surefire way to kill them. For such strokes, blood transfusions are used to stabilize the patient and, if needed, doctors will intervene to remove some of the fluid build-up and thus lower pressure on the rest of the brain. In severe cases, doctors can also attempt a mechanical thrombectomy — a direct intervention to remove the blood clot from the vessel it lodged in. This procedure isn’t available in all hospitals and care units as it requires specialized equipment; it’s usually employed up to 24 hours after symptoms onset at most.

The 3 to 4 and a half-hour time frame is used as a kind of gold standard for saving a CVA patient’s life. But the harsh truth is that once a stroke happens, some type of permanent damage to the brain (and thus, permanent symptoms) is usually unavoidable. However, it’s not a guarantee, and doing nothing will almost always be fatal. If you notice any of these signs in others or yourself, drop everything and call emergency services for help.

Exactly what happens after the stroke, how quick the recovery is, and what long-term effects it has are highly dependent upon where in the brain this stroke happened. The symptoms are caused by a lack of oxygen for neurons to feed and not the actual clot or hemorrhage that leads to it, and thus typically arise suddenly and affect one side of the body. Typical signs one is happening to you include numbness, weakness, tingling sensations, and loss of or changes in vision. Other common symptoms include difficulty speaking or understanding speech, vertigo, issues with maintaining balance or consciousness.

Strokes are sometimes accompanied by headaches, nausea, vomiting, especially for hemorrhagic strokes.

What causes them?

As a rule of thumb, keeping your circulatory system healthy should help ward off strokes — in other words, an active lifestyle and cardio help here. Keep tabs on your weight, follow a healthy diet as far as you can, exercise regularly, don’t smoke, and monitor your blood pressure to be as safe as possible. People who have high blood pressure or cholesterol levels, those suffering from diabetes, and smokers are particularly at risk of developing a stroke. Individuals who have underlying heart rhythm disturbances are also at risk, especially those with atrial fibrillation.

But no matter why it happens, you now know how to spot the signs of a stroke and how to act fast to keep everyone safe.

Different types of foods are associated with different types of stroke

A large European study reports intriguing associations between diet and heart health.

Fruits and vegetables are your best ally against strokes. Credits: Unsplash.

Stroke is the second leading cause of death worldwide. A stroke occurs when the blood supply to the brain is interrupted or reduced, preventing brain tissues from oxygenating properly.

There are two main causes of stroke: ischemic strokes (caused by a blocked artery) and hemorrhagic strokes, caused by leaking or bursting of a blood vessel.

About 85% of strokes are ischaemic and 15% are hemorrhagic, and both are associated with lifestyle choices (high blood pressure, smoking, and unhealthy dieting).

Most studies look at total stroke risk, and don’t analyze the separate effects of hemorrhagic and ischemic strokes (or just focus on the latter, which is more common). In a new study, however, the dietary habits of more than 418,000 people in nine European countries were correlated to the separate types of stroke risk.

Fruits, vegetables, and fibers

Unsurprisingly, people with higher consumption of fruit, vegetables, fiber were less likely to suffer from strokes — but only when it comes to ischaemic strokes; there was no significant association with a lower risk of hemorrhagic stroke.

Dr. Tammy Tong, the first author of the paper and a nutritional epidemiologist at the Nuffield Department of Population Health, University of Oxford (UK), said:

“The most important finding is that higher consumption of both dietary fiber and fruit and vegetables was strongly associated with lower risks of ischaemic stroke, which supports current European guidelines. The general public should be recommended to increase their fiber and fruit and vegetable consumption if they are not already meeting these guidelines.

According to the study, every 10 grams of fiber a day was associated with a 23% lower risk of ischemic stroke — equivalent to 2 fewer cases per 1,000 people over 10 years. For fruits and vegetables, there was a 13% lower risk for every 200g.

Cereal is an excellent source of fiber. Image credits: Daria Nepriakhina.

So you can get an idea how much that means, three slices of wholemeal toast provide around 10 grams of fibers, a portion of broccoli provides around 3 grams, and an apple has under 2 grams. According to the European Society of Cardiology (ESC) and the World Health Organization, you should consume at least 400g of fruit and vegetables a day, and 30-40 grams of fiber.

Eggs and cheese

Surprisingly, cheese and yogurt were also linked to a lower risk of ischaemic stroke and had no significant association with hemorrhagic stroke. While unsweetened yogurt is generally considered to be healthy, the connection between cheese and heart health is still controversial.

In moderation, eggs might even be good for you. Image credits: Elle May.

Speaking of controversial, the study also looked at the correlation between eggs and stroke risk. Eggs have long been a controversial topic when it comes to heart health. Traditionally, they were considered to be bad, as they raise the level of cholesterol. But recent studies have found conflicting evidence, with some even suggesting that in moderation, eggs can improve heart health. This latest study suggests that while a greater consumption of eggs is associated with a higher risk of hemorrhagic stroke, it does not affect the risk of the much more common ischemic stroke.

Strengths and limitations

Isolating the impact of diet alone remains an extremely challenging matter. This study only analyzed correlation and did not look at the causation, which would require a completely different type of study altogether.

The study also assessed people’s food consumption at only one point in time, when they joined the study — so no information can be drawn about diet changes that would cause an increase or decrease in stroke risk.

However, the study’s strengths lie in its large sample size and follow-up period. Over 400,000 men and women from nine countries (Denmark, Germany, Greece, Italy, The Netherlands, Norway, Spain, Sweden and the United Kingdom) were recruited to the European Prospective Investigation into Cancer and Nutrition (EPIC) study between 1992 and 2000, filling out questionnaires about their diet, lifestyle, and medical history. They were followed up for an average of 12.7 years, during which there were 4,281 cases of ischaemic stroke and 1,430 cases of hemorrhagic stroke.

“Our study also highlights the importance of examining stroke subtypes separately, as the dietary associations differ for ischaemic and hemorrhagic stroke, and is consistent with other evidence, which shows that other risk factors, such as cholesterol levels or obesity, also influence the two stroke subtypes differently,” concludes Tong.

Journal Reference: “The associations of major foods and fibre with risks of ischaemic and haemorrhagic stroke: a prospective study of 418,329 participants in the EPIC cohort across nine European countries”, by Tammy Tong et al. European Heart Journal. doi:10.1093/eurheartj/ehaa007.

Is that bowl of ramen giving you a stroke? A study says ‘maybe’

Ramen could be bad for you, according to a new study.

Image via Pixabay.

Researchers at the Jichi Medical University report that the high level of sodium (salt) in ramen could increase your chances of having a stroke. The team tracked various types of restaurants and health data among different regions of Japan and found that areas with a high number of ramen shops record more deaths by stroke than other Japanese prefectures, but not more heart attacks. Do note that the study established a correlation between the two (i.e. there are more stroke victims in areas with more ramen shops), but not a causative one.

Noodles to die for

“The prevalence of ramen restaurants in Japanese prefectures has a significant correlation with the stroke mortality rate,” the study concluded.

Ramen is, in short, delicious. This broth-and-noodle mix served in a bowl is a Japanese take on a traditional Chinese dish, and is enjoyed by people around the world.

However, not all may be right amidst the flavors. The team aimed to examine the relationship between diet and certain health concerns, chiefly that of the risk of stroke, in Japan. They compared various types of cuisine and different regions of the country to health data and restaurant prevalence.

Four categories of restaurants were considered: ramen, fast food, French or Italian, and udon or soba (two other types of noodle dishes). For health data, the team obtained age- and sex-adjusted stroke and heart attack mortality rates for each Japanese prefecture from a 2017 national study.

All in all, prefectures with a high number of ramen shops tend to see more stroke deaths than other Japanese prefectures, but not more heart attacks. Tohoku (in the northern Kanto region) and the southern regions of the Kyushu island have higher stroke mortality than other areas in Japan, the team reports. The Kinki region and southern Kanto region have low stroke mortality rates, they add. This distribution correlates very well to the prevalence of ramen restaurants, the team explains. They believe the high sodium content of the dish helps promote stroke.

Take the findings with a pinch of salt (pun intended). The team couldn’t obtain detailed information on the diets of the stroke victims used in the study, so they can’t tell whether ramen is the culprit. What the team found here is a correlation, meaning they can tell that areas with more ramen shops experience more deaths by stroke, but not that they cause those deaths.

The authors highlight that ramen is a popular, traditional dish, and as such is enjoyed in homes, not just restaurants — which they could not factor into this study. Furthermore, instant ramen is a popular snack all over the world but was also not part of the study as it’s virtually impossible to track its sales. On the other hand, ramen has many components such as soy, tonkotsu (a broth made from simmered pork marrow or bone), miso, and salt; more research is needed to establish which of these components (if any) have a strong bearing on stroke risk. Side dishes usually served with ramen, such as dumplings and rice, further compound the issue.

“These side dishes may include confounding nutritional factors,” the scientists write.

The paper “Ramen restaurant prevalence is associated with stroke mortality in Japan: an ecological study” has been published in the Nutrition Journal.

Cow pats.

Why do pets like pats?

Why do we, too, like pats for that matter?

Pig.

Think it’ll turn into a handsome prince?
Image credits Juda / Pixabay.

If you happen to have your own little, warm ball of fur back home, you know how much they love to be pet. But why do they like it, exactly? And do we humans like it, too? Let’s find out.

Skin-deep

Dogs love belly rubs. Cats break into a purr when you scratch that one special place between their ears. Hugs give us comfort and pleasure. If you hit your hand on something, a quick rub will reduce the pain.

All of these are fundamented on the sense of touch and show what a massive role it plays on our emotional state. While not all touches are pleasurable, all mammals seem to agree that a longer, slighter stroking motion feels good.

This particular type of motion stimulates a set of neurons known as MRGPRB4+, reported this study published in Nature Neuroscience in 2007. The authors worked with genetically-engineered mice, whose MRGPRB4+ neurons were modified to light up when activated (optogenetics). Pet-like stroking patterns of touch — and only this pattern of touch — at temperatures around that of human skin activated the neurons, the team found, inducing a pleasant sensation in the animal.

These neurons are connected to hair follicles in the skin and are relatively widely-spaced. Their layout is what makes them only respond to long stroking motions, and not more localized ones like pinching or poking.

Orange cat pet.

Image credits Linnaea Mallette.

We also have these neurons built into the follicles of hair-covered portions of our skin. This suggests that MRGPRB4+ neurons respond to touch on the skin itself, not to motions transmitted through strands of hair. This is also supported by the fact that an individual can experience a pleasant sensation from petting, hugging, or stroking even after experiencing hair loss or shaving; if the MRGPRB4+ neurons were tied to hair strands, instead of follicles, this wouldn’t have been the case.

“The researchers suspect similar sensory neurons with comparable properties exist in humans and most furry mammals,” explained David Anderson, one of the study’s co-authors.

“Since the sensation is connected to hair follicles, animals with many of them, such as cats and dogs, likely feel waves of pleasure when being petted. The neurons that detect stroking are probably wired into higher brain circuits that produce a reward or pleasure.”

To validate these findings, the team further modified some mice so that the same neurons could be activated biochemically, via a drug injection. When given the choice between two chambers, a control one where nothing happened and one where the drug-induced touch sensation occurred, the mice opted for the latter. This implied that the animals actually found the sensations caused by MRGPRB4+ neuron activation to be pleasurable. The mice also showed fewer signs of stress after receiving their chemical pat.

So, to recap, furry, hairy animals (i.e. mammals) enjoy the sensation of being pet. It is mediated by neurons connected to hair follicles in the skin and only caused by deliberate, slow, gentle, and relatively long strokes on the skin or fur. But we’re still missing a why — why did mammals evolve to experience pleasure from these patterns of touch?

Making buddies

Grooming.

“So how are you how’s the kids?”
Image credits Anthony / Pixabay.

For mammals, especially social ones, touch is a great way to make friends and strengthen bonds. Our wild cousins groom each other to remove harmful parasites from their fur since they can’t do it by themselves. But past research has shown that they engage in this behavior far more than than necessary from a purely hygienic standpoint. So, while grooming might have a very practical, even critical purpose, primates also seem to simply get a kick out of it and do it for fun or to socialize. It’s how they hang out.

Us humans aren’t typically big on public displays of grooming, but we also employ touch socially. Hugs, handshakes, a tap on the shoulder, they’re small gestures that can go a long way in strengthening familial or social bonds.

The mammal enjoyment of pats probably started out as a practical ritual — for example, as grooming — and our physiology later evolved to encourage the activity with positive sensations. Such behavior likely represented an evolutionary advantage as it promotes health, hygiene, bonding, and trust among the group, thereby increasing the survival chances of all its members. Alternatively, it is possible that this enjoyment of pats helps baby mammals keep warm by balling up together with their parents and siblings, thus conferring a selective advantage at a young age.

Regardless of why it happens, the end result is extremely effective at promoting bonding, social interaction, and good moods. Activation of the MRGPRB4+ neurons releases endorphins and oxytocin into the brain (these help with pain relief, relaxation, and bonding) and may lead to temporarily-reduced cortisol (a stress hormone) levels. This chemical cocktail puts us, or our pets, at ease, nips aggression in the bud, and induces a state of pleasure.

In your brain

One paper published in NeuroImage in 2016 looked into the patterns of “brain activation during 40min of pleasant touch” — which sounds quite enjoyable. The authors worked with 25 participants who “were stroked for 40min with a soft brush while they were scanned with functional Magnetic Resonance Imaging [fMRI], and rated the perceived pleasantness of the brush stroking.”

What they found was that stroking heavily activates neurons in the somatosensory cortex initially, although this dwindles in intensity over time — likely due to stimulus habituation. Stimulus habituation is the thing that makes you less sensitive to a particular smell after being exposed to it for a while, why you eventually stop feeling the chair under you or the smartphone in your right pocket.

At the same time, activity levels in the orbitofrontal gyrus (OFC, also known as the orbitofrontal cortex) and the putamen increase, stabilizing at about 20-minute mark. Certain structures of the insular cortex (the posterior insula) also see greater activity during this time. The team believes this increase in cerebral activity comes down to the subjective pleasure each participant was feeling — pleasure is how your brain rewards you for doing something.

The workings of the orbitofrontal cortex have been linked to depression in humans. In particular, reports one study published in Brain in 2016, subjects with depression showed weaker neural connections between the medial (middle) OFC and the hippocampus, which is associated with memory. They also showed stronger neural connections between the lateral OFC and other areas of the brain. The study worked with 421 patients with major depressive disorder and 488 control subjects.

The study’s authors explain that the medial OFC activates when processing or ‘administering’ rewards in the form of pleasure. It’s not yet understood exactly what those weaker connections mean, but it does suggest that people with depression may find it more difficult to access and recall happy or positive memories. At the same time, the lateral OFC — which enjoys stronger connections with other brain areas — is involved in processing or administering the non-rewards: science-speak for ‘punishments’.

To tie it all into a neat little bow, one paper published in Current Biology last year reported that the “lateral OFC is a promising new stimulation target for treatment of mood disorders” such as depression. The team worked with 25 subjects, using electrodes to stimulate various areas of their brains while monitoring and recording their (self-reported) mood via a daily questionnaire.

Patting, stroking, massages — they activate the neurons in the OFC, which is exactly what the team achieved using their direct stimulation techniques. A literal gentle touch, then, may be just what you need when you’re struggling with depression.

And hey, if nobody’s around to pet you, grab a brush, clear out 20 minutes of your schedule, and go hack your OFC.

Two or more diet sodas a day may increase risk of stroke

A comprehensive study of women over 50 shows that dieting done wrong can lead to unwanted healthy outcomes. Drinking two or more Diet Cokes a day was associated with a 16% increase in the risk of early death, researchers reported.

Although many well-intended people use low-calorie sweetened drinks to lose weight, this may put their health at risk. According to the researchers, such beverages are associated with a higher risk for stroke and heart disease.

The research team, led by Dr. Yasmin Mossavar-Rahmani from the Albert Einstein College of Medicine in the Bronx, New York, analyzed data on 81,714 post-menopausal women, whose average age was 50 to 79 at the start of the study. The participants were tracked for an average of 12 years.

Women who consumed two or more artificially sweetened diet beverages were 31% more likely to have a clot-based stroke and 29% more likely to have heart disease. Among the participants, African-American women formed the most vulnerable group.

“Many well-meaning people, especially those who are overweight or obese, drink low-calorie sweetened drinks to cut calories in their diet. Our research and other observational studies have shown that artificially sweetened beverages may not be harmless and high consumption is associated with a higher risk of stroke and heart disease,” said Mossavar-Rahmani.

The study, performed by the American Heart Association and American Stroke Association, was observational, meaning that the researchers could not directly prove that sweetened drinks cause stroke and heart problems through a causal link. We also don’t yet know which artificial sweeteners may be harmful and which may be harmless. Previously, studies established a link between diet beverages and stroke, dementia, Type 2 diabetes, obesity, and metabolic syndrome, suggesting that zero-calorie drink may be just as bad as sugary ones. A 2017 study found that diet soda might even hurt the brain.

“Unfortunately, current research simply does not provide enough evidence to distinguish between the effects of different low-calorie sweeteners on heart and brain health. This study adds to the evidence that limiting use of diet beverages is the most prudent thing to do for your health,” said Rachel K. Johnson, Ph.D., R.D., professor of nutrition emeritus

There is still much research to be done in order to investigate the effects of low-calorie sweetened beverages on our health. In the meantime, evidence so far suggests that the most prudent thing to do is to avoid them. Perhaps the best choice for a non-calorie drink is water.

The findings were reported in the journal Stroke

Lifting weights may be better for the heart than cardio

Strength training may protect people from heart attacks and stroke better than running or cycling, a new study suggests.

Credit: Pixabay.

Researchers at St. George’s University in Grenada analyzed data from the 2005-2006 National Health and Nutrition Examination Survey in the U.S. The data included information on the types of physical activity performed by  4,086 adult participants, but also the presence of cardiovascular risks, such as high blood pressure, high cholesterol, overweightedness, or diabetes.

The research team looked for an association between cardiovascular risk facts and the type of physical activity, which could be either static (i.e. push-ups, static rowing, lifting weights, dips, arm and leg raises, and hand grips) or dynamic (i.e. walking, jogging, cycling, swimming, and all sorts of sports from tennis to volleyball).

The results suggest that strength training offers more benefits for cardiovascular health than dynamic exercises, also known as ‘cardio’. Static exercises, the authors reported, led to better weight outcomes and blood pressure, and fewer incidences of diabetes. But that’s not to say cardio isn’t good for the heart — far from it! The researchers say that both types of workouts offer protection against cardiovascular problems. What’s more, individuals who did both strength training and cardio fared better than those who only practiced a single type of exercise.

“Both strength training and aerobic activity appeared to be heart healthy, even in small amounts, at the population level,” said Maia P. Smith, statistical epidemiologist and assistant professor in the Department of Public Health and Preventive Medicine at St. George’s University. “Clinicians should counsel patients to exercise regardless — both activity types were beneficial. However, static activity appeared more beneficial than dynamic, and patients who did both types of physical activity fared better than patients who simply increased the level of one type of activity.”

According to the new study, 36% of the participants aged 21 to 44 engaged in static exercises and 28% in dynamic exercises. For those aged 45 and older, the figures were 25% and 21%, respectively.

“One interesting takeaway was that both static and dynamic activity were almost as popular in older people as younger,” Smith said. “I believe this gives clinicians the opportunity to counsel their older patients that they will fit into the gym or the road race just fine. The important thing is to make sure they are engaging in physical activity.”

The findings were presented at the 2018 American College of Cardiology Latin America Conference that took place last week in Lima, Peru.

Tissue regrown brain.

Bioengineered gel heals the brains of stroke-injured mice, paves way for human treatment

Researchers from the University of California – Los Angeles (UCLA) have developed a gel that helped stroke-damaged brains of rats heal.

Tissue regrown brain.

Tissue regrown in cavities injected with the gel. Red tubes are blood vessels. They are growing into the site of the stroke in the center of the image. Green filaments are axons. The blue ovoids are cell nuclei in the tissue.
Image credits UCLA Health.

Brains have a limited capacity for recovery after damage or disease. They don’t regrow blood vessels, can’t construct synapses or larger tissue structures anew. Which is bad news because we use our brains for a lot of things. In recognition of this fact, a team of UCLA researchers has been hard at work developing a way to coax our brains into regenerating, just like your skin would after a scratch.

The gel they developed has proven itself on stroke-damaged brains of mice models — a world first — potentially paving the way for human medical applications.

“We tested this in laboratory mice to determine if it would repair the brain in a model of stroke, and lead to recovery,” said Dr. Thomas Carmichael, paper co-author.

“This study indicated that new brain tissue can be regenerated in what was previously just an inactive brain scar after stroke.”

When the brain’s tissues are damaged, such as what happens in the case of a stroke, they don’t heal back. Instead, they go through a process reminiscent of scar formation: the dead tissue is gobbled up, absorbed by the brain. This results in a cavity without any blood vessels or neurons.

The team, led by Dr. Tatiana Segura, a former Professor of Chemical and Biomolecular Engineering at UCLA, developed the gel to coax the surrounding, healthy brain tissue into healing the injured area. The material contains molecules that stimulate blood vessel growth and anti-inflammatory compounds (inflammation results in actual scars and impedes regrowth of functional tissue). The gel hardens to about the same degree as brain tissue and is meant to provide a scaffolding for the brain to regenerate on.

To test the compound, Segura and her team injected the gel into stroke cavities in the brains of mice. After 16 days, the cavities contained regenerated brain tissue, including neural networks the team reports. The mice with new neurons showed improved motor behavior, though exactly why this happened isn’t yet clear.

“The new axons could actually be working,” said Segura. “Or the new tissue could be improving the performance of the surrounding, unharmed brain tissue.”

The gel was ultimately broken down and absorbed by the body, leaving behind only bran-new brain tissue.

The team hopes their work will pave the way for recovery in cases of acute stroke, or the period immediately after such an event — that period, they add, is five days for mice and two months for humans. In the future, the team also plans to explore whether their gel can be used to treat mice long after the stroke injury.

The paper “Dual-function injectable angiogenic biomaterial for the repair of brain tissue following stroke” has been published in the journal Nature Materials.

More than just relaxation: Frequent sauna bathing reduces risk of stroke

A new study will bring a smile to regular sauna goers: aside from being relaxing and making you feel good, saunas are actually healthy for you.

This story originates in Finland, where modern saunas were likely invented, and where most houses include one. No one loves saunas quite like the Finns, so it’s the perfect place to study their effect on the human body. Here, researchers recruited 1,628 men and women aged 53 to 74 years living in the eastern part of the country, tracking their sauna-taking habits and risk of stroke.

Participants were divided into three groups — those taking about one sauna per week, those taking a sauna two to three times a week, and those taking a sauna four to seven times a week. Results showed that the more participants took saunas, the less of a stroke risk they had.

People who took the most saunas were 60% less likely to have a stroke than people who took only one sauna per week — even after researchers compensated for other factors such as high cholesterol, smoking, diabetes, age, sex, and physical activity. For those who took 2-3 saunas per week, stroke risk decreased by 14% compared to the first group. Even people who took about one sauna per week had a decreased stroke risk.

“These results are exciting because they suggest that this activity that people use for relaxation and pleasure may also have beneficial effects on your vascular health,” said study author Setor K. Kunutsor, of the University of Bristol in the UK. “Sauna bathing is a safe activity for most healthy people and even people with stable heart problems. More research is needed to confirm this finding and to understand the ways that saunas affect stroke risk.”

This is not the first study to highlight the health benefits of sauna taking. However, it is the first to show that saunas also help to fend off strokes.

“Previous studies have shown that sauna bathing may be associated with a reduced risk of high blood pressure, dementia and death from cardiovascular disease, but this is the first study on sauna use and the risk of stroke,” Kunutsor said. “Saunas appear to have a blood pressure lowering effect, which may underlie the beneficial effect on stroke risk.”

It’s important to note that this is an observational study — researchers did not show a cause-effect relationship between saunas and strokes. Another limitation is that all participants were Finnish, and findings might not carry over other populations. Lastly, this only showed the results of traditional Finnish saunas, not infrared chambers or other heating rooms.

In a recent study, the same team also showed that sauna bathing has acute effects on the stiffness of the arterial wall, reducing blood pressure and improving cardiac function parameters.

Journal Reference: ‘Sauna bathing reduces the risk of stroke in Finnish men and women: A prospective cohort study’ by Kunutsor, Setor; Khan, Hassan; Zaccardi, Francesco ; Laukkanen, Tanjaniina; Willeit, Peter; Laukkanen, Jari A. in Neurology

Hip hop music teaches children to recognize stroke and act quickly, study finds

Researchers have discovered that a musical movement that uses hip-hop music to educate economically-disadvantaged minority children and their parents about strokes has shown promising results in helping the increase of stroke awareness.

Via YouTube

“The lack of stroke recognition, especially among blacks, results in dangerous delays in treatment,” said Olajide Williams, M.D., M.S., study author and associate professor of neurology at Columbia University Medical Center, New York Presbyterian Hospital. “Because of those delays, only a quarter of all stroke patients arrive at the hospital within the ideal time for clot-busting treatment.”

A simple 9-1-1 call can save someone’s life. Calling an ambulance immediately when stroke symptoms start could increase the rate of optimal stroke treatment by 24%. It is very important for people to start recognizing the symptoms and know what to do in this kind of situation. Strokes kill four times more 35- to 54-year-old black Americans than white Americans.

Sadly, a lot of stroke awareness campaigns have been limited by the high costs of advertising, lack of cultural tailoring and low penetration into ethnic minority populations. But not all of them — “Hip Hop Stroke”, a three-hour multimedia stroke awareness intervention that teaches children rap songs about strokes, has shown great success in stroke education.

Scientists studying more than 3,000 4th through 6th graders from 22 public schools in New York City and a group of 1,144 of their parents have discovered that this campaign increased optimal stroke knowledge from 2% of children before the intervention to 57% right after. Another encouraging finding was that three months after the campaign had ended, 24% of children remembered all they had learned.

“Hip Hop Stroke” uses original hip-hop songs, comic books, and cartoon-style videos to make the kids remember facts about strokes. One of the invented acronyms of the project was F-A-S-T, which refers to stroke warning signs: Face dropping, Arm weakness, Speech difficulty, Time to call 9-1-1. Famous rapper Doug E. Fresh lent a hand in the artistic process and composed music and lyrics for the campaign.

“Rhymes have been shown to have quantifiable educational value,” said Dr. Williams.

Parents also learned new things. Pre-intervention, only 3% of the adults could identify stroke symptoms. That figure rose to 20% after they watched the educational videos. Three months later, 17% retained the information.

Dr. Williams, also known as the Hip Hop Doc, said that time is of the essence when it comes to stroke and clot-busting treatment.

“Every minute a stroke continues 1.9 million brain cells die. The earlier the treatment, the better the outcome,” he declared.

Williams has been conducting this study for over the past five years. He is delighted by the results and hopes that the free program will soon be used around the country.

“The program’s culturally-tailored multimedia presentation is particularly effective among minority youth or other groups among whom Hip Hop music is popular,” Williams said. “One unique aspect of the program is that the children who receive the program in school are used as ‘transmission vectors’ of stroke information to their parents and grandparents at home. Our trial showed that this is an effective strategy.”

https://www.youtube.com/watch?v=OlxWsWu9Y-Q

The paper was published in the American Heart Association Journal Stroke.

Google AI can now look at your retina and predict the risk of heart disease

Google researchers are extremely intuitive: just by looking into people’s eyes they can see their problems — cardiovascular problems, to be precise. The scientists trained artificial intelligence (AI) to predict cardiovascular hazards, such as strokes, based on the analysis of retina shots.

The way the human eye sees the retina vs the way the AI sees it. The green traces are the pixels used to predict the risk factors. Photo Credit: UK Biobank/Google

After analyzing data from over a quarter million patients, the neural network can predict the patient’s age (within a 4-year range), gender, smoking status, blood pressure, body mass index, and risk of cardiovascular disease.

“Cardiovascular disease is the leading cause of death globally. There’s a strong body of research that helps us understand what puts people at risk: Daily behaviors including exercise and diet in combination with genetic factors, age, ethnicity, and biological sex all contribute. However, we don’t precisely know in a particular individual how these factors add up, so in some patients, we may perform sophisticated tests … to help better stratify an individual’s risk for having a cardiovascular event such as a heart attack or stroke”, declared study co-author Dr. Michael McConnell, a medical researcher at Verily.

Even though you might think that the number of patients the AI was trained on is large, AI networks typically work with much larger sample sizes. In order for neural networks to be more accurate in their predictions, they must analyze as much data as possible. The results of this study show that, until now, the predictions made by AI cannot outperform specialized medical diagnostic methods, such as blood tests.

“The caveat to this is that it’s early, (and) we trained this on a small data set,” says Google’s Lily Peng, a doctor and lead researcher on the project. “We think that the accuracy of this prediction will go up a little bit more as we kind of get more comprehensive data. Discovering that we could do this is a good first step. But we need to validate.”

The deep learning applied to photos of the retina and medical data works like this: the network is presented with the patient’s retinal shot, and then with some medical data, such as age, and blood pressure. After seeing hundreds of thousands of these kinds of images, the machine will start to see patterns correlated with the medical data inserted. So, for example, if most patients that have high blood pressure have more enlarged retinal vessels, the pattern will be learned and then applied when presented just the retinal shot of a prospective patient. The algorithms correctly discovered patients who had great cardiovascular risks within a 5-year window 70 percent of the time.

“In summary, we have provided evidence that deep learning may uncover additional signals in retinal images that will allow for better cardiovascular risk stratification. In particular, they could enable cardiovascular assessment at the population level by leveraging the existing infrastructure used to screen for diabetic eye disease. Our work also suggests avenues of future research into the source of these associations, and whether they can be used to better understand and prevent cardiovascular disease,” conclude the authors of the study.

The paper, published in the journal Nature Biomedical Engineering, is truly remarkable. In the future, doctors will be able to screen for the number one killer worldwide much more easily, and they will be doing it without causing us any physical discomfort. Imagine that!

Light-moderate drinking is good for your heart

Beer, liquor and wine lovers – rejoice! According to researchers from the Norwegian University of Science and Technology (NTNU) people who drink alcoholic drinks regularly, but in small quantities  are less prone to heart failure and heart attacks than those who rarely or never drink. In other words, 3-5 drinks a week can be good for your heart.

A few beers a week can be good for your heart. Image via Pixabay.

Imre Janszky, a professor of social medicine at the Norwegian University of Science and Technology (NTNU) confirmed what we all hoped was real: when consumed with moderation, alcohol helps the heart (he means physically, not metaphorically). Also, it doesn’t matter what you drink, it’s more about how much you drink.

“It’s primarily the alcohol that leads to more good cholesterol, among other things. But alcohol can also cause higher blood pressure. So it’s best to drink moderate amounts relatively often,” he says.

He conducted two studies, the first of which came out in September, and the second in January. The studies showed that those who drank three to five drinks per week were 33 per cent less prone to heart failure than those who abstained or drank infrequently. In the case of heart attacks, the risk appears to be reduced by 28 percent with each additional one-drink increment. To some, this may come as a surprise – but to researchers, it was no surprise at all.

In fact, there seems to be a consensus that 3-5 small drinks a week are good for you, and not just against strokes.

“The relationship between alcohol and heart health has been studied in many countries, including the USA and southern European nations. The conclusions have been the same, but the drinking patterns in these countries are very different than in Norway. In countries like France and Italy, very few people don’t drink,” says Janszky. “It raises the question as to whether earlier findings can be fully trusted, if other factors related to non-drinkers might have influenced research results. It may be that these are people who previously had alcohol problems, and who have stopped drinking completely,” he says.

However, drinking alcohol isn’t necessary for a good heart and people shouldn’t pick up drinking just to be healthy – that’s a pathway to disaster.

“I’m not encouraging people to drink alcohol all the time. We’ve only been studying the heart, and it’s important to emphasize that a little alcohol every day can be healthy for the heart. But that doesn’t mean it’s necessary to drink alcohol every day to have a healthy heart,” says Janszky.

 

Wearable FES-robot hybrid eases stroke recovery

Hong Kong PolyU has designed a new FES (functional electrical stimulation) –  robot hybrid that promises to ease recovery of mobility in stroke victims.

Credit: Hong Kong PolyU

Cerebrovascular accidents (more commonly known as strokes) take place when poor blood flow in a certain area of the brain causes cell death. It is the third leading cause of death in the United States, with approximately 795,000 recorded cases each year, claiming the lives of more than 140.000 people each year in the U.S alone, according to the U.S. Center for Disease Control and Prevention. Common symptoms of stroke include hemiparesis (in more than 80% of stroke survivors) or a total inability to move or feel on one side of the body. After such an event, regular exercise is needed for the patient to recover motor function in the affected areas of the body.

Dubbed the “Rehab Sleeve”, the device was designed by Dr Hu Xiaoling at the Hong Kong based PolyU’s Interdisciplinary Division of Biomedical Engineering. The team was supported by the Institute of Textiles and Clothing, Industrial Center and other organizations. It combines pressure and moisture management to allow for comfortable long-term use in patients with functional electric stimulation, a technique that uses electrical currents to activate nerve endings controlling extremities affected by paralysis. It interprets the user’s motions as electrical signals that can be used to control a computer, allowing  for a combination of training tasks with interactive applications and games.

With a modular design and equipped with a bracing system, the Rehab Sleeve is comfortable to wear and allows for a lot of flexibility in usage: the various modules can be used at once or separately to maximize training efficiency. The device’s effectiveness in training has been evaluated in over 30 patients for three to six months, with preliminary results showing that compared to conventional training it can better accelerate the recovery of patients’ upper-limb functionality. Patients usually require 20 sessions of training using the Rehab Sleeve.

Your hand shake is an indicator of your heart’s health

You can find out a lot about a man by his handshake – about his personality, his feelings towards you, or… his heart health. According to a new Canadian study, a firm handshake is a reliable indicator of good health; they actually want to use handshake tests as initial ways to gauge the risk of heart attack and stroke.

Image via MorgueFile.

 

The study analyzed 140,000 patients aged between 35 and 70 in 17 countries, monitoring their health over 4 years. The first thing they noticed was a national variation in grip strength – Swedes have the firmest handshakes, while Pakistanis have the limpest. They then established a baseline; the average grip strength was 300 newtons, the force it takes to lift 30.6 kgs off the ground. Every 50­-newton drop below this was associated with a 16 per cent rise in the mortality risk, and in particular, a 17 percent risk of mortality risk associated with heart disease. In other words, the limper your hand shake tends to be, the more likely you are to suffer heart issues.

Does that mean that Swedes for example have much better hearts than Pakistanis? Well, I couldn’t find any data to directly back up that idea, but overall stroke rates have declined sharply in Sweden over the past 25 years, as have the dangers associated with strokes. Meanwhile, the Pakistani population has one of the highest risks of coronary heart disease (CHD) in the world. So for those two extremes, statistical data seems to back up this study.

Scientists actually believe that handshakes can be used as inexpensive methods of identifying someone’s risk of a heart disease. Of course, this is nowhere near as accurate as an actual test, but it seems to be a very good indicator.

“Doctors or other healthcare professionals can measure grip strength to identify patients with major illnesses such as heart failure who are at particularly high risk of dying from their illness,” said Darryl Leong, an assistant professor of medicine at McMaster University in Hamilton, Ontario, who led the investigation.

But the handshakes have to be corrected for several factors, including size, weight, muscular mass and ethnicity. More research is also needed to understand exactly why this correlation happens – it’s clearly connected to the blood supply to the hand muscles, but the exact mechanism is still somewhat a mystery.

(A, B) Echoplanar axial diffusion-weighted MRI (DWI) shows left posterior cerebral artery territory diffusion restriction including the left visual cortex (large arrow) and the splenium of the corpus callosum (small arrow). (C) Catheter angiogram, left vertebral artery injection, anterior posterior projection shows occlusion of the left posterior cerebral artery (large arrow) and constrictions and dilations of the right posterior cerebral artery consistent with probable primary angiitis of the CNS. (c) Neurology

Peculiar medical cases: The woman who can write, but can’t read

M.P., a kindergarten teacher and expert reader, was hit by a stroke and, in the aftermath, her brain underwent some irreversible transformations. It’s hard to imagine the confusion and fright the 40-year-old woman must have felt when shortly after her stroke, while in the classroom trying to read to children – her biggest source of fulfillment – she realized that the paper she was holding in her hands was filled with undecipherable symbols.

M.P. can understand and speak English perfectly as before, she can even write words, but oddly enough she can’t read. The rare condition, first described in 1892, is called alexia without agraphia. A paradox of chance, M.P. had distinguished herself during her career for the various reading techniques she had employed in her classes while working with children. The emotional strain was almost too much to bear.

“One day my mom was with the kids in the family, and they were all curled up next to each other, and they were reading. And I started to cry, because that was something I couldn’t do. I could be there, but I couldn’t pick up the book and read it. That’s something that I’d always done, and it’s something I had a lot of pleasure from. And I couldn’t do it.”

This unique pattern of deficits is caused by subcortical lesions that functionally isolate the left angular gyrus, or “language zone,” from the visual cortex. The paper in the journal Neurology describing her case lists a number of patterns of lesions that may have been responsible.

  • a single lesion to the splenium of the corpus callosum that stretches posterolaterally so as to interrupt white matter tracts running from the visual cortices of both hemispheres to the left angular gyrus,
  • lesions to both the splenium and the left primary visual cortex, or
  • lesions involving both the splenium and the lateral geniculate nucleus. In each case, the language zone is robbed of its visual inputs but remains intact. Etiologies of these lesions include posterior cerebral artery territory infarct, tumor, or demyelinating disorders such as multiple sclerosis or acute disseminated encephalomyelitis.

(A, B) Echoplanar axial diffusion-weighted MRI (DWI) shows left posterior cerebral artery territory diffusion restriction including the left visual cortex (large arrow) and the splenium of the corpus callosum (small arrow). (C) Catheter angiogram, left vertebral artery injection, anterior posterior projection shows occlusion of the left posterior cerebral artery (large arrow) and constrictions and dilations of the right posterior cerebral artery consistent with probable primary angiitis of the CNS. (c) Neurology

(A, B) Echoplanar axial diffusion-weighted MRI (DWI) shows left posterior cerebral artery territory diffusion restriction including the left visual cortex (large arrow) and the splenium of the corpus callosum (small arrow). (C) Catheter angiogram, left vertebral artery injection, anterior posterior projection shows occlusion of the left posterior cerebral artery (large arrow) and constrictions and dilations of the right posterior cerebral artery consistent with probable primary angiitis of the CNS. (c) Neurology

Blind to words

Her word blindness didn’t rend her oblivious to emotional responses when gazing upon certain words, though, suggesting that somewhere she could still read, but not consciously decipher text.

For instance, when shown the word ‘dessert’ in writing, M.P. exclaimed, ‘Oooh, I like that!’ When shown the word ‘asparagus’ moments later, however, her response was rather different. ‘I’m not doing this word! Something’s upsetting me about this word!’ she exclaims.

Nor have these intuitions been without utility. S.P. [M.P.’s mother] relates a recent anecdote in which, during an afternoon therapy session, her daughter was shown 2 letters from the mailbox at home. Nonplussed, M.P. quickly handed one letter back to her mother and tucked the other into her purse, saying, ‘This is my friend, and this is your friend.’ When asked who these friends were, she could not say, but their names nevertheless provoked an emotional response that served as a powerful contextual clue.

 

M.P.’s stroke took place in December 2012. Obviously she couldn’t hold her old job at the kindergarten anymore, but the women eventually recovered in spirit and is currently engaged actively in her community. She has a job at a local fitness center, where she works at the front desk and sells membership and sometimes volunteer in the park district.

[ALSO READ] Woman can literally feel sound after stroke

While unfortunate, M.P.’s story is also a hopeful one, since despite all the adversities she found the strength to go on and adapt. A more poetic fellow than myself would say she’s a hallmark for human ingenuity, and it’s easy to understand after you learn how M.P. managed to find a way to read.

Given a word, M.P. will direct her attention to the first letter, which she is unable to recognize. She will then place her finger on the letter and begin to trace each letter of the alphabet over it in order until she recognizes that she has traced the letter she is looking at. ‘That is the letter M,’ she declares, after tracing the previous 12 letters of the alphabet with her finger while deciphering a word in front of her. Three letters later, she is able to shorten this exercise with a guess: ‘This word is ‘mother,” she announces proudly.

Slow walker? You might just get dementia

The speed at which someone walks and the likelihood of dementia don’t have absolutely anything in common at a first glance, but according to a study published in the British Medical Journal in 2009 there is a ‘strong association’ between the two.

They also said at a conference that grip strength in middle-aged men was linked to the likelihood of a stroke. Dr Erica Camargo, who conducted the study, explains:

“While frailty and lower physical performance in elderly people have been associated with an increased risk of dementia, we weren’t sure until now how it impacted people of middle age.”

In order to prove this, she conducted brain scans on 2,410 people who were, on average, 62 years old, comparing them with walking speed and grip strength. Analysis revealed that as years passed, those who walked slower had an increased risk of dementia, and those with a weaker grip had an increased stroke risk.

“These are basic office tests which can provide insight into risk of dementia and stroke and can be easily performed by a neurologist or general practitioner. “Further research is needed to understand why this is happening and whether preclinical disease could cause slow walking and decreased strength.”

Although the reason and mechanics behind these issues are not yet fully understood, it is another perfect example of how common issues can severely affect your health, like bad sleep is linked with Alzheimer’s, for example.

Dr Anne Corbett, research manager at the Alzheimer’s Society, said: “Before people take stock in the strength of a handshake or the speed you cross the road, more research is needed to understand why and what other factors are involved.

“The good news is that there are many things you can do to reduce your risk of developing dementia. “We recommend you eat a healthy balanced diet, don’t smoke, maintain a healthy weight, take regular exercise; and get your blood pressure and cholesterol checked regularly.”

However, many are skeptical about the validity of this study, so one thing’s for sure: more tests have to be conducted before we can surely state that there is a connection between walking and dementia.

Via BBC

Woman can literally feel sound after stroke

After she suffered a stroke, a 36-year-old professor started to feel sounds. In the beginning she didn’t know what was happening when a radio announcer’s voice made her tingle, or when during a flight she became physically uncomfortable.

Neuroscientist at the City College of New York and the Graduate Center of the City University of New York believe they understand what happened in this particular case of synesthesia, after enhanced brain scans showed that new links had grown between its auditory part, which processes sound, and the somatosensory region, which handles touch.

“The auditory area of her brain started taking over the somatosensory area,” says Tony Ro, one of the researchers.

Based on this peculiar case, the scientists who have researched the woman’s case have presented a paper at the recent at a meeting of the Acoustical Society of America, where they stated that a deep connection between hearing and touch is nested inside each of us. Their theory was formulated around vibrations and how they trigger certain nerves in both touch and hearing sensory parts of the human body. A phone vibrating will be felt by the skin, while a phone on a ring tone will create sound waves which vibrate the eardrum.

Bearing this in mind, researchers have shown that hearing a sound can boost touch sensitivity, which Ro calls the mosquito effect. The name comes from an obvious example in which the bug’s buzz makes our skin prickle, meaning that you’ll actually be able to sense the mosquito touching your skin better, according to a 2009 paper he published in Experimental Brain Research.

Further MRI scans of people’s brains have shown that the auditory region can activate during a touch, and some speculate that chunks of brain specialized to understand frequency may play a role in crossing the wires. How the two senses come together in the end is still confussing for scientists.

Still, image being able to feel all sorts of stuff based on the vibrations the various kind of music you’d like to listen. How would listening to Lady Gaga would differ from Led Zeppelin or Nat King Cole or classical music?