'Spring forward' to daylight saving time brings surge in fatal car crashes

Deadly accidents spike 6% in week after time change

January 30, 2020

Science Daily/University of Colorado at Boulder

A study of 732,000 accidents over two decades has found that the annual switch to daylight saving time is associated with a 6% increase in fatal car crashes that week.

Fatal car accidents in the United States spike by 6% during the workweek following the "spring forward" to daylight saving time, resulting in about 28 additional deaths each year, according to new University of Colorado Boulder research.

The study, published January 30 in the journal Current Biology, also found that the farther west a person lives in his or her time zone, the higher their risk of a deadly crash that week.

"Our study provides additional, rigorous evidence that the switch to daylight saving time in spring leads to negative health and safety impacts," said senior author Celine Vetter, assistant professor of integrative physiology. "These effects on fatal traffic accidents are real, and these deaths can be prevented."

The findings come at a time when numerous states, including Oregon, Washington, California and Florida, are considering doing away with the switch entirely, and mounting research is showing spikes in heart attacks, strokes, workplace injuries and other problems in the days following the time change.

For the study -- the largest and most detailed to date to assess the relationship between the time change and fatal motor vehicle accidents -- the researchers analyzed 732,835 accidents recorded through the U.S. Fatality Analysis Reporting System from 1996 to 2017. They excluded Arizona and Indiana, where Daylight Savings Time was not consistently observed.

After controlling for factors like year, season and day of the week, they found a consistent rise in fatal accidents in the week following the spring time change. Notably, that spike moved in 2007, when the Energy Policy Act extended daylight saving time to begin on the second Sunday of March instead of the first Sunday in April.

"Prior to 2007, we saw the risk increase in April, and when daylight saving time moved to March, so did the risk increase," said Vetter. "That gave us even more confidence that the risk increase we observe is indeed attributable to the daylight saving time switch, and not something else."

With the arrival March 9 of daylight saving time, clocks shift forward by one hour, and many people will miss out on sleep and drive to work in darkness -- both factors that can contribute to crashes.

Those on the western edge of their time zone, in places like Amarillo, Texas, and St. George, Utah, already get less sleep on average than their counterparts in the east -- about 19 minutes less per day, research shows -- because the sun rises and sets later but they still have to be at work when everyone else does.

"They already tend to be more misaligned and sleep-deprived, and when you transition to daylight saving time it makes things worse," said first author Josef Fritz, a postdoctoral researcher in the Department of Integrative Physiology. In such western regions, the spike in fatal accidents was more than 8%, the study found.

The increase kicks in right away, on the Sunday when the clocks spring forward, and the bulk of the additional fatal accidents that week occur in the morning.

Changes in accident patterns also occur after the "fall back" time change, the study showed, with a decline in morning accidents and a spike in the evening, when darkness comes sooner.

Because they balance each other out, there is no overall change in accidents during the "fall back" week.

In all, over the course of the 22 years of data analyzed, about 627 people died in fatal car accidents associated with the spring shift to Daylight Savings Time, the study estimated.

Because the data only include the most severe of car accidents, the authors believe the results underestimate the true risk increase to drivers when time springs forward.

"Our results support the theory that abolishing time changes completely would improve public health," said Vetter. "But where do we head from here? Do we go to permanent standard time or permanent daylight saving time?"

Generally speaking, research has shown, it's better for sleep, the body clock, and overall health to have more morning light and less evening light, as is the case under standard time. Under permanent daylight saving time, mornings would stay dark later in winter all over the country, with the western parts of each time zone seeing the sun the latest, Vetter noted.

"As a circadian biologist, my clear preference is toward standard time."

https://www.sciencedaily.com/releases/2020/01/200130144410.htm

Algae shown to improve gastrointestinal health

Project is the first to test green algae on symptoms related to human digestion

January 27, 2020

Science Daily/University of California - San Diego

A green, single-celled organism called Chlamydomonas reinhardtii has served as a model species for topics spanning algae-based biofuels to plant evolution. While algae have been used as dietary nutraceuticals that provide beneficial oils, vitamins, proteins, carbohydrates and antioxidants, the benefits of consuming C. reinhardtii were previously unexplored. Researchers have now completed the first study in humans demonstrating that C. reinhardtii helps improve human gastrointestinal problems related to irritable bowel syndrome, including diarrhea, gas and bloating.

A widespread, fast-growing plant called Chlamydomonas reinhardtii is famous in scientific laboratories due to its position as the world's most exhaustively studied algae.

For decades, the green, single-celled organism, which primarily grows in wet soil, has served as a model species for research topics spanning from algae-based biofuels to plant evolution. While other species of algae have been used as dietary nutraceuticals that provide beneficial oils, vitamins, proteins, carbohydrates, antioxidants and fiber, the benefits of consuming C. reinhardtii were previously unexplored.

Researchers at the University of California San Diego recently completed the first study examining the effects of consuming C. reinhardtii and demonstrated that the algae improves human gastrointestinal issues associated with irritable bowel syndrome (IBS) such as diarrhea, gas and bloating. Results of the project are published in the Journal of Functional Foods.

"People have been looking at this algae for decades, but this is the first study to show what many of us have suspected -- it's good for you," said principal investigator and algae expert Stephen Mayfield, a distinguished professor in UC San Diego's Division of Biological Sciences and co-director of the Food and Fuel for the 21st Century Program (FF21). "This is exciting because it demonstrates a clear benefit: If you have IBS-like symptoms, this is good for you."

For years researchers in Mayfield's laboratory have been exploring C. reinhardtii as a cost-competitive and sustainable source of valuable plant-based products, specifically pharmaceuticals and biofuels. Now, working with several collaborators, including UC San Diego's John Chang (School of Medicine), Rob Knight (School of Medicine, Jacobs School of Engineering and Center for Microbiome Innovation) and the San Diego-based startup Triton Algae Innovations, they turned their attention towards investigating the algae as a nutritious food additive for improving human health.

The C. reinhardtii biomass used in the study, which was grown by Triton Algae Innovations, was subject to rigorous safety testing and designated as "Generally Recognized As Safe" by the U.S. Food and Drug Administration, green-lighting the use of the organism in a human study.

Preliminary data in mouse studies demonstrated that consuming C. reinhardtii significantly reduced the rate of weight loss in mice with acute colitis, which is generally linked to inflammation of the digestive tract. Building off these results, the researchers set out to test for a similar effect when the algae was consumed by human volunteers, including those with and without symptoms associated with IBS. Volunteers consumed daily spoonfuls of powdered C. reinhardtii biomass and reported their gastrointestinal health for one month. Of the hundreds of interested participants in the project, data from 51 volunteers met the study's requirements for inclusion in the final data analyses.

Results showed that participants who suffered from a history of frequent gastrointestinal symptoms reported significantly less bowel discomfort and diarrhea, significantly less gas or bloating and more regular bowel movements.

"The benefits of consuming this species of algae were immediately obvious when examining the data from both mice and humans who suffered from gastrointestinal symptoms," said Frank Fields, a research scientist in Mayfield's lab and lead author of the paper. "I hope that this study helps destigmatize the thought of incorporating algae and algae-based products into your diet -- it is a fantastic source of nutrition and we have now shown that this species of algae has additional benefits to animal and human health."

Volunteers also were provided with stool sampling kits and sent samples to the American Gut Project, a citizen science effort led by Knight and his lab, to assess any changes in their microbiomes. The results indicated that the gut microbiome composition remained diverse, which is typical of healthier individuals, and that no significant changes to the composition of their gut microbiome occurred during the study as a result of consuming the algae.

The researchers say much more testing with larger groups of participants across longer time periods is needed. At this point, they are unclear about how the algae works to improve gastrointestinal health. The scientists believe the benefits could be traced to a bioactive molecule in algae or perhaps a change in gene expression of gut bacteria caused by algae consumption.

Still, the observed results in human volunteers led them to conclude in the paper that "the addition of C. reinhardtii into the diet will not only add nutritional value but may also function to relieve some gastrointestinal symptoms of certain individuals."

https://www.sciencedaily.com/releases/2020/01/200127134813.htm

An egg a day not tied to risk of heart disease

 

January 27, 2020

Science Daily/McMaster University

The controversy about whether eggs are good or bad for your heart health may be solved, and about one a day is fine. A team of researchers found the answer by analyzing data from three large, long-term multinational studies.

A team of researchers from the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences found the answer by analyzing data from three large, long-term multinational studies.

The results suggest there is no harm from consuming eggs. Given that the majority of individuals in the study consumed one or fewer eggs per day, it would be safe to consume this level, says Mahshid Dehghan, first author and a PHRI investigator.

"Moderate egg intake, which is about one egg per day in most people, does not increase the risk of cardiovascular disease or mortality even if people have a history of cardiovascular disease or diabetes," she said.

"Also, no association was found between egg intake and blood cholesterol, its components or other risk factors. These results are robust and widely applicable to both healthy individuals and those with vascular disease."

The details are published in The American Journal of Clinical Nutrition.

Although eggs are an inexpensive source of essential nutrients, some guidelines have recommended limiting consumption to fewer than three eggs a week due to concerns they increase the risk of cardiovascular disease.

Previous studies on egg consumption and diseases have been contradictory, said Salim Yusuf, principal investigator of the study and director of PHRI.

"This is because most of these studies were relatively small or moderate in size and did not include individuals from a large number of countries," he said.

The researchers analyzed three international studies conducted by the PHRI. Egg consumption of 146,011 individuals from 21 countries was recorded in the PURE study and in 31,544 patients with vascular disease from the ONTARGET and the TRANSEND studies.

The data from these three studies involved populations from 50 countries spanning six continents at different income levels, so the results are widely applicable, said Yusuf.

https://www.sciencedaily.com/releases/2020/01/200127134727.htm

Research leads to life changing improvement for some people living with depression

Deep brain stimulation study targets people with treatment-resistant depression

January 27, 2020

Science Daily/University of Calgary

Researchers have completed a study investigating the effects of two different methods of deep brain stimulation (DBS), short pulse and long pulse, for treatment-resistant depression. The findings showed that both methods of stimulation were equally safe and effective in reducing depressive symptoms. Some study participants have experienced a massive positive change in their lives.

Beth MacKay knew at a young age that she saw the world differently than many of her friends and family. She thought her pessimism and cynicism were rooted in realism, a proud reminder of her Scottish roots, and not a sign of an underlying medical condition. But, that understanding of herself changed when at the age of 17, she attempted suicide.

"I was diagnosed with depression, but looking back, it started much earlier," says MacKay, now 31. "Doctors believe it may have started when I was 10 or 11-years-old. As a child I would go through periods where I couldn't sleep, I didn't want to go to school, and I was constantly sick."

MacKay's parents tried to find help and support for her. They thought her symptoms may have been related to a learning disorder, but no one suspected depression could be the cause.

Prescribed anti-depressants and therapy, MacKay went on to university. She noticed everyone around her seemed to be functioning, but she couldn't get out of bed. She spent the next several years pretending to be okay. She would sleep most of the day, and get up-and-out only long enough to put on a front to show people she was fine. It seemed that no matter what treatment options she tried nothing made life manageable.

"Everyday felt like climbing up a mountain. Something as simple as showering, doing dishes or throwing in a load of a laundry felt too difficult at times," recalls MacKay.

Always open to trying something else to improve her life, MacKay volunteered for a research study at the University of Calgary. Dr. Rajamannar Ramasubbu, MD, was investigating the effects of two different methods of deep brain stimulation (DBS), short pulse and long pulse, for treatment-resistant depression.

"It can be very difficult to find study participants for research like this," says Ramasubbu, a professor in the departments of Psychiatry and Clinical Neurosciences, and member of The Mathison Centre for Mental Health Research & Education and the Hotchkiss Brain Institute at the Cumming School of Medicine (CSM). "The procedure is invasive, so many clinicians are reluctant to recommend it. It requires implanting an electrode into the brain that is connected to a pulse generator that is implanted under the clavicle into the chest."

Just as pacemakers deliver electrical impulses to help control abnormal heart rhythms, DBS devices deliver electrical impulses to help neurons (brain cells) within the brain communicate more efficiently with each other.

"Depression is caused by abnormalities in the neural circuit responsible for emotional regulation," says Ramasubbu. "The region of the brain we target (subcallosal cingulate) is the junction of the limbic and frontal regions. Stimulating this area helps to keep a balance between these two unique systems."

Multi-disciplinary team collaborates on DBS study

Participants are awake when the device is implanted. Dr. Zelma Kiss, MD/PhD, a neurosurgeon and co- principal investigator of the study performed the procedure at the Foothills Medical Centre (FMC).

Participants were randomized into two groups, one group received short pulse stimulation, the other long pulse width stimulation. After six months, treatment switched for those who did not respond in the first six months. Researchers used the Hamilton Depression Rating Scale to measure change in symptoms.

"Both methods of stimulation were equally safe and effective in reducing depressive symptoms," says Ramasubbu. "50 per cent of the participants responded to the stimulation with 50 per cent reduction in symptoms. Of which 30 per cent experienced complete improvement in their symptoms, especially those who received long pulse width stimulation."

MacKay says she's experienced a massive change. "Basically I was nearly dead and now I'm mostly alive. I'm still figuring out what life feels like, because it feels so different and so much better than before the implant."

Ramasubbu adds more research is needed to determine which patients with treatment resistant depression will benefit from DBS. Study participants ranged in age from 20 to 70, with younger participants showing better improvement than older participants.

https://www.sciencedaily.com/releases/2020/01/200127164325.htm

Treatment for depression must also restore proper functioning of the blood-brain barrier

January 21, 2020

Science Daily/Université Laval

To better treat people with depression, not only must we treat the neurons affected by the disease, but we must also restore the integrity of the barrier that regulates exchanges between blood circulation and the brain. This is the conclusion of a study published today in PNAS by Université Laval researchers and their international collaborators.

"Between 30% and 50% of those suffering from depression respond either poorly or not at all to antidepressants," says main author Caroline Ménard, professor at Université Laval's Faculty of Medicine and researcher at the Cervo Brain Research Centre. "This suggests that biological mechanisms other than those directly affecting neurons are at play," adds professor Ménard, who also holds the Sentinel North Research Chair on the Neurobiology of Stress and Resiliency.

Caroline Ménard and her colleagues showed in 2017 that the appearance of depressive symptoms in mice subjected to social stress was linked to increased permeability of the blood-brain barrier. They also discovered that this permeability is due to a decrease in a protein called claudin-5.

"In the study published today, we wanted to find out what causes the decrease in claudin-5 in mice under social stress and why some mice are resilient to social stress while others exhibit depressive symptoms," explains Professor Ménard.

The researchers examined blood-brain barrier cells in depressed stressed mice, resilient stressed mice, and control mice. Their observations show that the epigenetic processes that allow the expression of the claudin-5 gene are more readily activated in resilient mice. They also observed that the resilient mice produce less of one of the proteins that inhibit expression of the claudin-5 gene.

Conversely, depressed stressed mice express more of an enzyme called HDAC1 that triggers a loss of claudin-5. "When a chemical compound is used to block HDAC1, the depressive mice produce more claudin-5 and their social interactions spontaneously increase," says Professor Ménard.

Thanks to the Douglas Bell Canada Brain Bank, the researchers were able to verify whether the same mechanisms were present in humans. "We found that expression of HDAC1 was greater in depressed people without treatment at the time of death than in subjects who were taking antidepressants or in the control group. This increase correlated with a decrease in claudin-5."

These results suggest that efforts to develop better treatments for depression should not be limited to finding new molecules that target affected neurons. Researchers must also find a way to close the gaps in the blood-brain barrier to ensure its proper functioning. "For now, we don't know of any molecules that increase the expression of claudin-5 and would allow us to directly restore the barrier's impermeability," adds Professor Ménard. "Our future work will focus on evaluating the effect of different pharmacological approaches and lifestyle habits on the integrity of this barrier in order to promote resilience."

https://www.sciencedaily.com/releases/2020/01/200121113033.htm

Beauty sleep could be real, say body clock biologists

January 15, 2020

Science Daily/University of Manchester

Biologists from The University of Manchester have explained for the first time why having a good night's sleep really could prepare us for the rigours of the day ahead.

The study in mice and published in Nature Cell Biology, shows how the body clock mechanism boosts our ability to maintain our bodies when we are most active.

And because we know the body clock is less precise as we age, the discovery, argues lead author Professor Karl Kadler, may one day help unlock some of the mysteries of aging.

The discovery throws fascinating light on the body's extracellular matrix -which provides structural and biochemical support to cells in the form of connective tissue such as bone, skin, tendon and cartilage.

Over half our body weight is matrix, and half of this is collagen -- and scientists have long understood it is fully formed by the time we reach the age of 17.

But now the researchers have discovered there are two types of fibrils -- the rope-like structures of collagen that are woven by the cells to form tissues.

Thicker fibrils measuring about 200 nanometres in diameter -- a million million times smaller than a pinhead -- are permanent and stay with us throughout our lives, unchanged from the age of 17.

But thinner fibrils measuring 50 nanometres, they find, are sacrificial, breaking as we subject the body to the rigours of the day but replenishing when we rest at night.

The collagen was observed by mass spectrometry and the mouse fibrils were observed using state of the art volumetric electron microscopy -- funded by the Wellcome Trust -- every 4 hours over 2 days.

When the body clock genes where knocked out in mice, the thin and thick fibrils were amalgamated randomly.

"Collagen provides the body with structure and is our most abundant protein, ensuring the integrity, elasticity and strength of the body's connective tissue," said Professor Kadler

"It's intuitive to think our matrix should be worn down by wear and tear, but it isn't and now we know why: our body clock makes an element which is sacrificial and can be replenished, protecting the permanent parts of the matrix.

He added: "So if you imagine the bricks in the walls of a room as the permanent part, the paint on the walls could be seen as the sacrificial part which needs to be replenished every so often.

"And just like you need to oil a car and keep its radiator topped up with water, these thin fibrils help maintain the body's matrix."

"Knowing this could have implications on understanding our biology at its most fundamental level. It might, for example, give us some deeper insight into how wounds heal, or how we age.

https://www.sciencedaily.com/releases/2020/01/200115120626.htm

Tea drinkers live longer

January 9, 2020

European Society of Cardiology

Drinking tea at least three times a week is linked with a longer and healthier life, according to a study published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).

"Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death," said first author Dr. Xinyan Wang, Chinese Academy of Medical Sciences, Beijing, China. "The favourable health effects are the most robust for green tea and for long-term habitual tea drinkers."

The analysis included 100,902 participants of the China-PAR project2 with no history of heart attack, stroke, or cancer. Participants were classified into two groups: habitual tea drinkers (three or more times a week) and never or non-habitual tea drinkers (less than three times a week) and followed-up for a median of 7.3 years.

Habitual tea consumption was associated with more healthy years of life and longer life expectancy.

For example, the analyses estimated that 50-year-old habitual tea drinkers would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than those who never or seldom drank tea.

Compared with never or non-habitual tea drinkers, habitual tea consumers had a 20% lower risk of incident heart disease and stroke, 22% lower risk of fatal heart disease and stroke, and 15% decreased risk of all-cause death.

The potential influence of changes in tea drinking behaviour were analysed in a subset of 14,081 participants with assessments at two time points. The average duration between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years.

Habitual tea drinkers who maintained their habit in both surveys had a 39% lower risk of incident heart disease and stroke, 56% lower risk of fatal heart disease and stroke, and 29% decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.

Senior author Dr. Dongfeng Gu, Chinese Academy of Medical Sciences, said: "The protective effects of tea were most pronounced among the consistent habitual tea drinking group. Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect."

In a subanalysis by type of tea, drinking green tea was linked with approximately 25% lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. However, no significant associations were observed for black tea.

Dr. Gu noted that a preference for green tea is unique to East Asia. "In our study population, 49% of habitual tea drinkers consumed green tea most frequently, while only 8% preferred black tea. The small proportion of habitual black tea drinkers might make it more difficult to observe robust associations, but our findings hint at a differential effect between tea types."

Two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors including high blood pressure and dyslipidaemia. Black tea is fully fermented and during this process polyphenols are oxidised into pigments and may lose their antioxidant effects. Second, black tea is often served with milk, which previous research has shown may counteract the favourable health effects of tea on vascular function.

Gender-specific analyses showed that the protective effects of habitual tea consumption were pronounced and robust across different outcomes for men, but only modest for women. Dr. Wang said: "One reason might be that 48% of men were habitual tea consumers compared to just 20% of women. Secondly, women had much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men."

She added: "The China-PAR project is ongoing, and with more person-years of follow-up among women the associations may become more pronounced."

The authors concluded that randomised trials are warranted to confirm the findings and provide evidence for dietary guidelines and lifestyle recommendations.

https://www.sciencedaily.com/releases/2020/01/200109105508.htm

Some surprisingly good news about anxiety

January 7, 2020

Science Daily/University of Toronto

Anxiety disorders are the most common type of psychiatric illness, yet researchers know very little about factors associated with recovery. A new University of Toronto study investigated three levels of recovery in a large, representative sample of more than 2,000 Canadians with a history of generalized anxiety disorder (GAD).

The study reports that 72% of Canadians with a history of GAD have been free of the mental health condition for at least one year. Overall, 40% were in a state of excellent mental health, and almost 60% had no other mental illness or addiction issues, such as suicidal thoughts, substance dependence, a major depressive disorder or a bipolar disorder, in the past year,

The definition of excellent mental health sets a very high bar. To be defined in excellent mental health, respondents had to achieve three things: 1) almost daily happiness or life satisfaction in the past month, 2) high levels of social and psychological well-being in the past month, and 3) freedom from generalized anxiety disorder and depressive disorders, suicidal thoughts and substance dependence for at least the preceding full year.

"We were so encouraged to learn that even among those whose anxiety disorders had lasted a decade or longer, half had been in remission from GAD for the past year and one-quarter had achieved excellent mental health and well-being," says Esme Fuller-Thomson, lead author of the study. Fuller-Thomson is Director of the University of Toronto's Institute for Life Course and Aging and Professor at the Factor-Inwentash Faculty of Social Work and the Department of Family & Community Medicine.

"This research provides a very hopeful message for individuals struggling with anxiety, their families and health professionals. Our findings suggest that full recovery is possible, even among those who have suffered for many years with the disorder," she says.

Individuals who had at least one person in their lives who provided them with a sense of emotional security and wellbeing were three times more likely to be in excellent mental health than those without a confidant.

"For those with anxiety disorders, the social support that extends from a confidant can foster a sense of belonging and self-worth which may promote recovery" says co-author Kandace Ryckman, a recent graduate of University of Toronto's Masters of Public Health.

In addition, those who turned to their religious or spiritual beliefs to cope with everyday difficulties had 36% higher odds of excellent mental health than those who did not use spiritual coping. "Other researchers have also found a strong link between recovery from mental illness and belief in a higher power," reports Fuller-Thomson.

The researchers found that poor physical health, functional limitations, insomnia and a history of depression were impediments to excellent mental health in the sample.

"Health professionals who are treating individuals with anxiety disorders need to consider their patients' physical health problems and social isolation in their treatment plans" says Ryckman.

The researchers examined a nationally representative sample of 2,128 Canadian community-dwelling adults who had a generalized anxiety disorder at some point in their lives. The data were drawn from Statistics Canada's Canadian Community Health Survey-Mental Health. This research was published online ahead of press this week in the Journal of Affective Disorders.

https://www.sciencedaily.com/releases/2020/01/200107131832.htm

Air pollution can worsen bone health

January 3, 2020

Science Daily/Barcelona Institute for Global Health (ISGlobal)

A new study with over 3,700 people in India associates air pollution with a higher risk to develop osteoporosis.

Some of the effects of air pollution on health are well documented -lung cancer, stroke, respiratory diseases, and a long etcetera- but for others there is less scientific evidence. Such is the case of bone health: there are only a few studies and results are inconclusive. Now, a study in India led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by "la Caixa," has found an association between exposure to air pollution and poor bone health.

Osteoporosis is a disease in which the density and quality of the bone is reduced. Globally, it is responsible for a substantial burden of disease and its prevalence is expected to increase due to aging of the population.

The new study performed by the CHAI Project, led by ISGlobal and published in Jama Network Open, analysed the association between air pollution and bone health in over 3,700 people from 28 villages outside the city of Hyberabad, in southern India.

The authors used a locally-developed model to estimate outdoor exposure at residence to air pollution by fine particulate matter (suspended particles with a diameter of 2.5 ?m or less) and black carbon. The participants also filled a questionnaire on the type of fuel used for cooking. The authors linked this information with bone health assessed using a special type of radiography that measures bone density, called dual-energy x-ray absorptiometry, and measured bone mass at the lumbar spine and the left hip.

The results showed that exposure to ambient air pollution, particularly to fine particles, was associated with lower levels of bone mass. No correlation was found with use of biomass fuel for cooking.

"This study contributes to the limited and inconclusive literature on air pollution and bone health," explains Otavio T. Ranzani, ISGlobal researcher and first author of the study. Regarding the possible mechanisms underlying this association, he says "inhalation of polluting particles could lead to bone mass loss through the oxidative stress and inflammation caused by air pollution."

Annual average exposure to ambient PM2.5 was 32.8 ?g/m3, far above the maximum levels recommended by the World Health Organisation (10 ?g/m3). 58% of participants used biomass fuel for cooking.

"Our findings add to a growing body of evidence that indicates that particulate air pollution is relevant for bone health across a wide range of air pollution levels, including levels found in high income and low-and medium income countries" says Cathryn Tonne, coordinator of the study and of the CHAI project. "

https://www.sciencedaily.com/releases/2020/01/200103111726.htm