Tag Archives: mortality

Air pollution could be responsible for 1 in 5 adult deaths worldwide

New research from the Harvard T.H. Chan School of Public Health explains that fossil fuel pollution could be responsible for 1 in 5 adult deaths worldwide.

Image credits Alexander Droeger.

Discussions around the use of fossil fuels today mostly revolve around their environmental impact, as well they should. But the life around us isn’t the only one that has to bear the costs of our reliance on such substances — their use, a new paper reports, has a human cost as well.

According to the authors, pollution generated by the burning of fossil fuels was responsible for around 8 million premature deaths in 2018, roughly 20% of all adult deaths worldwide in that year. The most heavily polluted areas saw the lion’s share of these deaths.

Burn hard die young

Half of those premature deaths were recorded in China and India, with Bangladesh, Indonesia, Japan, and the United States making up the rest. The deadly effects of fossil fuel pollution come down to the tiny particles (PM, particulate matter) generated by the burning of oil, gas, and especially coal. In around six Asian nations, such pollution accounts for over one-quarter of all mortality, the team adds.

However, that also means that lowering our use of fossil fuels, or at least finding ways to keep air quality in check, can prevent all those excess deaths.

All in all, air pollution is responsible for reducing the average lifespan by 4.1 years in China, 3.9 years in India, 3.8 years in Pakistan, and around 8 months on average in Europe. This goes to show how hard air pollution impacts Asia compared to both more developed and less developed areas. The figures reported in this paper are almost double those of previous estimates.

Previous estimates of deaths related to fossil fuel pollution were based on satellite data and surface-level observations to determine concentrations of PM2.5, the most deadly kind of particulate matter. These estimates, most recently provided by World Health Organization through the Global Burden of Disease, puts this number at around 7 million, with around 4 million of those being caused by outdoor pollution.

One limitation of these previous studies, however, is that they cannot determine the origin of the particles in question — these could come from burning fossil fuel as well as dust or wildfires. To get a better idea of their origin (and thus, how much of the problem is caused by fossil fuels) the team used GEOS-Chem, a 3-D atmospheric chemistry model, to look at the Earth’s surface in 50-by-60-kilometer (30-by-36-mile) blocks.

“Rather than rely on averages spread across large regions, we wanted to map where the pollution is and where people live,” said lead author Karn Vohra, a graduate student at the University of Birmingham.

Next, they fed in data regarding carbon emissions from several key fields, as well as NASA simulations of air circulation. After they calculated PM2.5 levels for each block, they used a novel risk assessment model to estimate how much damage these would cause public health, leading to the reported figures. Among the most common effects of air pollution, the team lists coronary heart disease and stroke (around half), followed by lung diseases and non-communicable conditions such as diabetes and high blood pressure for most of the rest.

The paper is awaiting publication in the journal Environmental Letters and is currently available on Harvard’s page.

Fermented soy products may reduce mortality risk

A new study reports finding a link between higher intake of fermented soy products such as miso and nato and a lower risk of all-cause mortality. However, at this point, the findings aren’t conclusive; further research is needed to establish a cause-and-effect relationship between the two.

A bowl of gochujang miso.
Image credits Jinwoo Lee.

Fermented soy products are quite widely consumed in Asian countries, particularly Japan. These include natto (soybeans fermented with Bacillus subtilis), miso (soybeans fermented with Aspergillus oryzae), and tofu (soybean curd). A new study aimed at studying the potential health benefits associated with these products reports that they may help reduce mortality from any cause, although the link is not yet properly established.

Spilling the beans

“In this study a higher intake of fermented soy was associated with a lower risk of mortality,” the authors write. “A significant association between intake of total soy products and all cause mortality was not, however, observed.”

“The findings should be interpreted with caution because the significant association of fermented soy products might be attenuated by unadjusted residual confounding.”

The team set out to investigate the association between several types of fermented soy products and death from any cause (“all-cause mortality”), from cancer, total cardiovascular disease (heart disease and cerebrovascular disease), respiratory disease, and injury.

The findings were drawn from a pool of 42,750 men and 50,165 women aged 45-74 who were taking part in the Public Health Centre-based Prospective Study, which includes 11 public health center areas in Japan. As part of the study, participants were asked to fill in detailed questionnaires regarding their dietary habits, lifestyle, and personal health. Residential registries and death certificates were used to track the evolution of these participants over a 15-year-period after filling in the questionnaires. Roughly 13,300 deaths were identified during this time.

All in all, the team reports, a higher intake of fermented soy was associated with a 10% lower risk of all-cause mortality. Participants who ate natto also had a “significantly” lower risk of cardiovascular mortality than those who did not eat natto, the team adds. Total (unfermented) soy and soy product intake, however, had no observable link to all-cause mortality, they add, or to cancer-related mortality.

The association stood firm even after the team adjusted for vegetable intake — higher rates of which are associated with better overall health and reduced mortality. Participants who consumed higher portions of natto were, on average, also chowing down on more vegetables than their peers, the team explains. Fermented soy products are higher in fiber, potassium, and other beneficial compounds than non-fermented soy products, the team explains. They believe this might underpin the association observed in this study.

However, they also strongly stress that this is an observational study. The team simply found that people who eat more of these products are less likely to die from certain causes, but that doesn’t mean the products themselves lead to decreased mortality. The authors controlled for several factors, including overall diet, body-mass index (BMI), smoking status, alcohol intake, and engagement in sports among many others. Still, unaccounted for factors (these are the ‘confounders’ they mention) could be causing the observed link.

Further research is needed “to refine our understanding of the health effects of fermented soy,” they add, noting that there is some evidence linking fermented soy products with various health benefits — so it’s a promising line of study.

“These efforts should be collaborative, including not only researchers but also policymakers and the food industry,” they conclude.

The paper “Association of soy and fermented soy product intake with total and cause specific mortality: prospective cohort study” has been published in the journal BMJ.

Pregnancy related deaths down by half in the last 25 years

Between reports of melting icecaps, starving polar bears and reports of food shortages, it’s easy to become pessimistic about life. But it’s not all bad, as a recently released report by the UN, published in The Lancet, shows how pregnancy-related deaths have fallen almost by half in the past 25 years.

Maternal mortality rates are down by half since 1990.
Image via flikr

Around 303,000 women died of complications during pregnancy or up to six weeks after giving birth in 2015 – down from 532,000 in 1990. While only nine countries hit the target set by the UN, WHO (World Health Organization) officials consider the results indicative of “huge progress” overall, with 39 countries dramatically lowering the number of pregnancy-related deaths.

“This report will show that by the end of 2015 maternal mortality will have dropped by 44% from its levels from 1990,” said Dr Lale Say, coordinator for reproductive health and research at the WHO.

But she warned that the progress was “uneven” – with 99% of deaths happening in developing countries.

“Many countries with high maternal death rates will make little progress, or will fall behind, over the next 15 years if we don’t improve the current number of available midwives and other health workers with midwifery skills,” said Dr Babatunde Osotimehin, executive director of the UN Population Fund.

Eastern Asia saw the greatest improvement, with maternal mortality falling from approximately 95 to 27 per 100,000 live births. The UN now aims to reduce the global ratio to less than 70 per 100,000 by 2030.

Tea vs coffee. A new study suggests coffee increases risk of non-cardiovascular mortality, while tea reduces these risks. Image: life-cafe.co.za

Drinking tea reduces risk of non-CV mortality. The opposite occurs for coffee

Tea vs coffee. A new study suggests coffee increases risk of non-cardiovascular mortality, while tea reduces these risks. Image: life-cafe.co.za

Tea vs coffee. A new study suggests coffee increases risk of cardiovascular mortality, while tea reduces these risks. Image: life-cafe.co.za

A recent study that assessed coffee and tea consumption habits of a whooping 131 000 people from France found that tea reduces non-cardiovascular mortality (non-CV) by 24%. Far from it, the same can’t be said about drinking coffee: consumers  had a higher CV risk profile than non-drinkers, particularly for smoking. Overall there’s a tendancy to have a higher risk profile for coffee drinkers and a lower risk profile for tea drinkers

The study involved 131 401 people aged 18 to 95 years who had a health check up at the Paris IPC Preventive Medicine Center between January 2001 and December 2008. Correspondents were followed-up over a mean period of 3.5 years, during which there were 95 deaths from CV and 632 deaths from non-CV causes. Coffee and tea consumption was self-assessed via a series of questionnaires. Consumers were grouped into three classes: none, 1 to 4, or more than 4 cups per day.

Non-coffee drinkers were more physically active, with 45% having a good level of physical activity compared to 41% of the heavy coffee drinkers. Professor Danchin said: “This is highly significant in our large population.” On the other end, physical activity increased with the number of cups of tea per day from 43% in the moderate tea drinkers to 46% in the heavy drinkers.

Heavy coffee drinkers (more than 4 cups a day) were significantly older than non-drinkers, with a mean age of 44 years, compared to 40 years.

Coffee drinkers were also found to be smokers in larger proportions than tea-drinkers. One-third (34%) of the non-drinkers of tea were current smokers compared to 24% of those who drank 1-4 cups per day and 29% of those who drank more than 4 cups.

Tea was associated with lower blood pressure than coffee, with a 4–5 mmHg decrease in SBP and 3 mmHg decrease in DBP in the heavy tea drinkers, compared to non-drinkers, when adjusted for age. The findings were presented at the European Society of Cardiology (ESC) Congress  by  by Professor Nicolas Danchin from France.

Here are some of the documented harmful effects of caffeine consumption: