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Author: Sima

Published on Leave a comment on Millions of Deaths Annually Due to Air Pollution?

A recent post (Air Pollution Can Kill You) discussed recent research that found that air pollution is linked to an overall increase in death rates, especially cardiovascular disease. But how many deaths each year are linked to air pollution? Recent research suggests that outdoor air pollution, mostly by fine particulate matter with a diameter smaller than 2.5 micrometers (PM2.5), leads to 3.3 million premature deaths per year worldwide, predominantly in Asia. The number one cause  worldwide is residential energy use such as heating and cooking, (India ,China, and the developing world).

But surprisingly agriculture or farming is number 2 worldwide. How can that be? Well, farms produce ammonia from fertilizer and animal waste. That ammonia then combines with sulfates from coal-fired power plants and nitrates from vehicle exhaust to form the soot particles that are the big air pollution killers. The United States had about 54,905 deaths in 2010 from soot and smog. Power plants and traffic (vehicle emissions) are big sources of the air pollution linked to deaths in the USA. From Medical Xpress:

Millions of premature deaths tied to air pollution

Outdoor air pollution leads to more than 3 million premature deaths per year, primarily in Asia, according to a letter published online Sept. 16 in Nature.

Johannes Lelieveld, Ph.D., from the Max Planck Institute for Chemistry in Germany, and colleagues used a global atmospheric chemistry model to investigate the link between premature mortality and seven emission source categories in urban and rural environments. The researchers found that outdoor air pollution, mostly by fine particulate matter with a diameter smaller than 2.5 micrometers (PM2.5), leads to 3.3 million premature deaths per year worldwide, predominantly in Asia. The largest impact on premature mortality globally comes from residential energy use such as heating and cooking, prevalent in India and China. In the United States, emissions from traffic and power generation are important. Agricultural emissions make the largest relative contribution to PM2.5 in the eastern United States, Europe, Russia, and East Asia, with the estimate of overall health impact depending on assumptions regarding particle toxicity. 

...continue reading "Millions of Deaths Annually Due to Air Pollution?"

Published on Leave a comment on We Each Give Off a Personal Microbial Cloud

Amazing! We each release a "personal microbial cloud" with its own "microbial cloud signature" every day. The unique combination of millions of bacteria (from our microbiome or community of microbes - including bacteria, viruses, fungi -  that live within and on us) can identify us. Not only do we each give off a unique combination, but we each give off different amounts of microbes - some more, some less. Some very common bacteria: Streptococcus, Propionobacterium, Corynebacterium, and Lactobacillus (among women).The microbes are given off with every movement, every exhalation, every scratching of the head, every burp and fart, etc. - and they go in the air around the person and settle around the person (they researchers even collected bacteria from dishes set on the ground around the person). From Science Daily:

The 'Pig-Pen' in each of us: People emit their own personal microbial cloud

We each give off millions of bacteria from our human microbiome to the air around us every day, and that cloud of bacteria can be traced back to an individual. New research focused on the personal microbial cloud -- the airborne microbes we emit into the air -- examined the microbial connection we have with the air around us. The findings demonstrate the extent to which humans possess a unique 'microbial cloud signature'.

To test the individualized nature of the personal microbial cloud, University of Oregon researchers sequenced microbes from the air surrounding 11 different people in a sanitized experimental chamber. The study found that most of the occupants sitting alone in the chamber could be identified within 4 hours just by the unique combinations of bacteria in the surrounding air. The findings appear in the September 22 issue of the open-access, peer-reviewed journal PeerJ.

The striking results were driven by several groups of bacteria that are ubiquitous on and in humans, such as Streptococcus, which is commonly found in the mouth, and Propionibacterium and Corynebacterium, both common skin residents. While these common human-associated microbes were detected in the air around all people in the study, the authors found that the different combinations of those bacteria were the key to distinguishing among individual people.

The analyses, utilizing analysis of suspended particulate matter and short-read 16S sequencing, focused on categorizing whole microbial communities rather than identifying pathogens. The findings emerged from two different studies and more than 14 million sequences representing thousands of different types of bacteria found in the 312 samples from air and dust from the experimental chamber.

"We expected that we would be able to detect the human microbiome in the air around a person, but we were surprised to find that we could identify most of the occupants just by sampling their microbial cloud," said lead author James F. Meadow, a postdoctoral researcher formerly from the Biology and the Built Environment Center at the University of Oregon."Our results confirm that an occupied space is microbially distinct from an unoccupied one, and and demonstrate for the first time that individuals release their own personalized microbial cloud," the authors concluded.

Image result for personal microbial cloud wikipediaSneeze. Credit: Wikipedia and CDC

Published on

 Perhaps a nutrient deficit is associated with depression? This study found that eating a Mediterranean diet or a similar diet in which fruits, vegetables, legumes (beans), nuts, and low in processed meats is associated with lower rates of depression. From Medical Xpress:

Fruit and vegetables aren't only good for a healthy body—they protect your mind too

Eating a Mediterranean diet or other healthy dietary pattern, comprising of fruit, vegetables, legumes, and nuts and low in processed meats, is associated with preventing the onset of depression, according to research published in the open access journal BMC Medicine. A large study of 15,093 people suggests depression could be linked with nutrient deficits..

The researchers compared three diets; the Mediterranean diet, the Pro-vegetarian Dietary Pattern and Alternative Healthy Eating Index-2010. Participants used a scoring system to measure their adherence to the selected diet, i.e. the higher the dietary score indicated that the participant was eating a healthier diet. Food items such as meat and sweets (sources of animal fats: saturated and trans fatty acids) were negatively scored, while nuts, fruits and vegetables (sources of omega-3 fatty acids, vitamins and minerals respectively) were positively scored.

The study included 15,093 participants free of depression at the beginning of the study. They are former students of the University of Navarra, Spain, registered professionals from some Spanish provinces and other university graduates....Questionnaires to assess dietary intake were completed at the start of the project and again after 10 years. A total of 1,550 participants reported a clinical diagnosis of depression or had used antidepressant drugs after a median follow-up of 8.5 years.

The Alternative Healthy Eating Index-2010 was associated with the greatest reduction of risk of depression but most of the effect could be explained by its similarity with the Mediterranean Diet. Thus, common nutrients and food items such as omega-3 fatty acids, vegetables, fruits, legumes, nuts and moderate alcohol intake present in both patterns (Alternative Healthy Eating Index-2010 and Mediterranean diet) could be responsible for the observed reduced risk in depression associated with a good adherence to the Alternative Healthy Eating Index-2010.

Almudena Sanchez-Villegas says, "A threshold effect may exist. The noticeable difference occurs when participants start to follow a healthier diet. Even a moderate adherence to these healthy dietary patterns was associated with an important reduction in the risk of developing depression. However, we saw no extra benefit when participants showed high or very high adherence to the diets....This dose-response pattern is compatible with the hypothesis that suboptimal intake of some nutrients (mainly located in low adherence levels) may represent a risk factor for future depression."

Two recent meta-analyses of studies looked at depression. The first found that in 12 out of 26 studies eating fish (but NOT fish-oil supplements) was linked to lower rates of depression. The researchers hypothesize that "Fish is rich in multiple beneficial nutrients, including n-3 polyunsaturated fatty acids, high-quality protein, vitamins, and minerals." Another meta-analysis looked at dietary patterns and depression and found that a high intake of fruit, vegetables, fish, and whole grains may be associated with a reduced depression risk. From Medscape:  Fish-Rich Diet May Significantly Reduce Depression Risk

Published on Leave a comment on Home Pesticide Use Linked to Childhood Cancer

Children exposed to insecticides (pesticides) at home have an increased risk of developing leukemia or lymphoma, a new review finds.The analysis, of 16 studies done since the 1990s, found that children exposed to indoor insecticides had an elevated risk of developing the blood cancers. There was also a weaker link between exposure to weed killers and the risk of leukemia.

There is also evidence from studies linking pesticides with neurological consequences, such as lower IQ and attention deficit hyperactivity disorder. Note: insecticides and weed-killers (herbicides) are both pesticides. The article also gives some non-chemical approaches to treating pests with non-chemical means.

From CNN: Report: Pesticide exposure linked to childhood cancer and lower IQ

Pesticide use in homes may increase the risk of children developing leukemia or lymphoma, a new report suggests. Researchers combined data from 16 earlier studies that had compared pesticide exposure between children who developed leukemia or lymphoma and those who did not. These studies estimated the level of insecticides and herbicides both inside the home and in the yard and outdoor residential space.

The researchers concluded that children who had been exposed to insecticides indoors were 47% more likely to have leukemia and 43% more likely to have lymphoma. Although leukemia and lymphoma are rare -- leukemia affects about five in 100,000 children in the United States -- they are among the common types of childhood cancers. "Childhood cancers are increasing year by year in this country....  ...continue reading "Home Pesticide Use Linked to Childhood Cancer"

Published on Leave a comment on Early Childhood Experiences Key to Preventing Allergies

It's official - the medical community has accepted that a key element in preventing allergies and asthma is early childhood exposure to allergens - whether peanuts, dust, or pets. Instead of avoiding the allergens (which was the medical advice for decades) - getting early exposure to them is key to preventing allergies. Apparently growing up on a farm is best (with exposure to farm dirt and dust), especially a dairy farm with animals and raw milk (a number of studies have found that unprocessed raw milk and its microbes also helps health). But if one doesn't live on a farm, then having furry pets in early childhood is also beneficial in reducing the incidence of allergies. The following study shows that microbes are involved - pet microbes were found in the guts of many of those children who did not develop early allergies! From Medscape:

Furry Pets 'Enrich' Gut Bacteria of Infants at Risk for Allergies

In a small, preliminary study, infants in households with furry pets were found to share some of the animals' gut bacteria - possibly explaining why early animal exposure may protect against some allergies, researchers say. The infants' mothers had a history of allergy, so the babies were at increased risk. It was once thought that pets might be a trigger for allergies in such children, the authors pointed out online September 3 in the Journal of Allergy and Clinical Immunology.

"Earlier it was thought that exposure to pets early in childhood was a risk factor for developing allergic disease," coauthor Dr. Merja Nermes, of the University of Turku in Finland, told Reuters Health by email. "Later epidemiologic studies have given contradictory results and even suggested that early exposure to pets may be protective against allergies, though the mechanisms of this protective effect have remained elusive."Adding pet microbes to the infant intestinal biome may strengthen the immune system, she said.  ...continue reading "Early Childhood Experiences Key to Preventing Allergies"

Published on Leave a comment on Air Pollution Can Kill You

Another study finding negative health effects from air pollution. This year I've posted several studies that found negative effects on the brain (and even cognition) from air pollution for people of all ages. Now this latest study found that in areas with air pollution, long-term exposure to outdoor fine particulate matter (PM2.5),which are fine particles in the air, are linked to an overall increase in risk of death, especially due to cardiovascular disease. The fine particles in the air contribute to the development of potentially fatal heart and lung diseases because they slip past the body's defenses and can be absorbed deep into the lungs and bloodstream. They are not sneezed or coughed out the way larger natural particles, like airborne soil and sand, are removed from the body's airways. From Science Daily:

Link between air pollution, increased deaths and increased deaths from heart disease affirmed

In what is believed to be the largest, most detailed study of its kind in the United States, scientists at NYU Langone Medical Center and elsewhere have confirmed that tiny chemical particles in the air we breathe are linked to an overall increase in risk of death. The researchers say this kind of air pollution involves particles so small they are invisible to the human eye (at less than one ten-thousandth of an inch in diameter, or no more than 2.5 micrometers across).

In a report on the findings, published in the journal Environmental Health Perspectives online Sept. 15, the scientists conclude that even minuscule increases in the amount of these particles (by 10 micrograms per cubic meter of air, for example) lead to an overall increased risk of death from all causes by 3 percent -- and roughly a 10 percent increase in risk of death due to heart disease. For nonsmokers, the risk increase rises to 27 percent in cases of death due to respiratory disease.

"Our data add to a growing body of evidence that particulate matter is really harmful to health, increasing overall mortality, mostly deaths from cardiovascular disease, as well as deaths from respiratory disease in nonsmokers," says lead study investigator and health epidemiologist George Thurston, ScD, a professor of population health and environmental medicine at NYU Langone. "Our study is particularly notable because all the data used in our analysis comes from government- and independently held sources."

According to Thurston, fine particles can contribute to the development of potentially fatal heart and lung diseases because they slip past the body's defenses and can be absorbed deep into the lungs and bloodstream. They are not sneezed or coughed out the way larger natural particles, like airborne soil and sand, are removed from the body's airways. Moreover, Thurston says, fine particles are usually made of harmful chemicals such as arsenic, selenium, and mercury, and can also transport gaseous pollutants, including sulfur and nitrogen oxides, with them into the lungs.

For their research, Thurston and his colleagues evaluated data from a detailed health and diet survey conducted by the National Institutes of Health (NIH) and the American Association of Retired Persons (AARP). The NIH-AARP study involved 566,000 male and female volunteers, ages 50 to 71, from California, Florida, Louisiana, New Jersey, North Carolina, Pennsylvania, and the metropolitan areas of Atlanta and Detroit. Analyzing information gathered about the participants between 2000 and 2009,....

Indeed, the team did not find any significant difference in the effect of particulate matter exposure between different sexes or age groups or by level of education. The researchers also noted that limiting the analysis to only the state of California, which has the most rigorous controls on air pollution, did not produce a different overall level of risk; instead, they found the same association between particulate matter exposure and increase in risk of death from all nonaccidental causes and from cardiovascular disease.

Published on Leave a comment on Time Spent Outside and Nearsightedness

Another study found that young children who more time spent outside in natural light for 3 years resulted in fewer cases of myopia (near-sightedness). Specifically, the good results were found from one additional 40-minute class of outdoor activities each school day, as well as parents encouraging their children to play outdoors after school hours, especially during weekends and holidays. So....those of you who are parents of children huddled inside - get them outside daily in the sunlight to soak up sunshine for vitamin D and to help their vision. From Science Daily:

Additional time spent outdoors by children results in decreased rate of nearsightedness

The addition of a daily outdoor activity class at school for three years for children in Guangzhou, China, resulted in a reduction in the rate of myopia (nearsightedness, the ability to see close objects more clearly than distant objects), according to a study in the September 15 issue of JAMA.

Myopia has reached epidemic levels in young adults in some urban areas of East and Southeast Asia. In these areas, 80 percent to 90 percent of high school graduates now have myopia. Myopia also appears to be increasing, more slowly, in populations of European and Middle Eastern origin. Currently, there is no effective intervention for preventing onset. Recent studies have suggested that time spent outdoors may prevent the development of myopia, according to background information in the article.

Mingguang He, M.D., Ph.D., of Sun Yat-sen University, Guangzhou, China, and colleagues conducted a study in which children in grade 1 from 12 primary schools in Guangzhou, China (six intervention schools [n = 952 students]; six control schools [n = 951 students], were assigned to 1 additional 40-minute class of outdoor activities, added to each school day, and parents were encouraged to engage their children in outdoor activities after school hours, especially during weekends and holidays (intervention schools); or children and parents continued their usual pattern of activity (control schools). The average age of the children was 6.6 years.

The 3-year cumulative incidence rate of myopia was 30.4 percent (259 cases among 853 eligible participants) in the intervention group and 39.5 percent (287 cases among 726 eligible participants) in the control group. Cumulative change in spherical equivalent refraction (myopic shift) after 3 years was significantly less in the intervention group than in the control group.

"Our study achieved an absolute difference of 9.1 percent in the incidence rate of myopia, representing a 23 percent relative reduction in incident myopia after 3 years, which was less than the anticipated reduction. However, this is clinically important because small children who develop myopia early are most likely to progress to high myopia, which increases the risk of pathological myopia. Thus a delay in the onset of myopia in young children, who tend to have a higher rate of progression, could provide disproportionate long-term eye health benefits," the authors write.

Published on

More research support for extra virgin olive oil and the Mediterranean diet being associated with anti-cancer effects, In a study conducted in Spain, women supplementing their diet with extra EVOO (extra virgin olive oil) had a lower incidence of breast cancer after about 5 years.

The Mediterranean diet stresses eating a lot of fruits, vegetables, seeds, nuts, legumes, whole grains, fish, and olive oil.

From Science Daily: Mediterranean diet plus olive oil associated with reduced breast cancer risk

Eating a Mediterranean diet supplemented with extra virgin olive oil was associated with a relatively lower risk of breast cancer in a study of women in Spain, according to an article published online by JAMA Internal Medicine.

The Mediterranean diet is known for its abundance of plant foods, fish and especially olive oil. Miguel A. Martínez-González, M.D., of the University of Navarra in Pamplona and CIBEROBN in Madrid, Spain, and coauthors analyzed the effects of two interventions with the Mediterranean diet (supplemented with extra virgin olive oil [EVOO] or nuts) compared with advice to women to follow a low-fat diet. Study participants in the two intervention groups were given EVOO (one liter per week for the participants and their families) or mixed nuts (30 grams per day: 15 grams of walnuts, 7.5 grams of hazelnuts and 7.5 grams of almonds).

From 2003 to 2009, 4,282 women (ages 60 to 80 and at high risk of cardiovascular disease) were recruited. Women were randomly assigned to the Mediterranean diet supplemented with EVOO (n=1,476), the Mediterranean diet supplemented with nuts (n=1,285) or the control diet with advice to reduce their dietary intake of fat (n=1,391). The women were an average age of 67.7 years old, had an average body mass index of 30.4, most of them had undergone menopause before the age of 55 and less than 3 percent used hormone therapy. During a median follow-up of nearly five years, the authors identified 35 confirmed incident (new) cases of malignant breast cancer.

The authors report that women eating a Mediterranean diet supplemented with EVOO showed a 68 percent relatively lower risk of malignant breast cancer than those allocated to the control diet. Women eating a Mediterranean diet supplemented with nuts showed a nonsignificant risk reduction compared with women in the control group.

The authors note a number of limitations in their study including that breast cancer was not the primary end point of the trial for which the women were recruited; the number of observed breast cancer cases was low; the authors do not have information on an individual basis on whether and when women in the trial underwent mammography; and the study cannot establish whether the observed beneficial effect was attributable mainly to the EVOO or to its consumption within the context of the Mediterranean diet. [The original study.]

Published on Leave a comment on Viruses Live in The Guts of Healthy Babies

Yes, even healthy newborns have a diversity of viruses in the gut - this is their virome (community of viruses), and it undergoes changes over time. In fact, the entire infant microbiome (community of microbes) is highly dynamic and the composition of bacteria, viruses and bacteriophages changes with age. One interesting finding is that initially newborn babies have a lot of bacteriophages (viruses that infect bacteria), but that these decline over the first two years of age. From Medical Xpress:

Viruses flourish in guts of healthy babies

Bacteria aren't the only nonhuman invaders to colonize the gut shortly after a baby's birth. Viruses also set up house there, according to new research at Washington University School of Medicine in St. Louis. All together, these invisible residents are thought to play important roles in human health.The study, published online Sept. 14 in Nature Medicine, reports data from eight healthy infants and is one of the first surveys of viruses that reside in the intestine. The investigators analyzed stool samples to track how the babies' bacterial gut microbiomes and viromes changed over the first two years of life.

"We are just beginning to understand the interplay between all the different types of life within our gut," said senior author Lori R. Holtz, MD, assistant professor of pediatrics. "They are not stand-alone communities. We also are seeing that the environment of the infant gut is extremely dynamic, which differs from the relative stability that has been shown in adults."The earliest stool samples were taken at 1-4 days of life, and even at this early time point, Holtz noted, viruses were present.  ...continue reading "Viruses Live in The Guts of Healthy Babies"

Published on Leave a comment on Low Vitamin D Levels Associated With Cognitive Decline Among Older Adults

New research has found that low vitamin D levels among older adults is associated with accelerated cognitive decline and impaired performance (particularly in areas of memory and executive function). The next research in this area will have to look at whether vitamin D supplementation will change (slow down) the decline. Please note that it is widely accepted that an average daily intake of 1000 IU  of D3 daily is safe. The best source of  vitamin D is sunlight. From Science Daily:

Low vitamin D among elderly associated with decline in cognition, dementia

Vitamin D insufficiency among the elderly is highly correlated with accelerated cognitive decline and impaired performance, particularly in domains such as memory loss that are associated with Alzheimer's disease and dementia, researchers with the UC Davis Alzheimer's Disease Center and Rutgers University have found. The effect is "substantial," with individuals with low vitamin D declining at a rate three times faster than those with adequate vitamin D levels. 

The researchers said their findings amplify the importance of identifying vitamin D insufficiency among the elderly, particularly high-risk groups such as African-Americans and Hispanics, who are less able to absorb the nutrient from its most plentiful source: sunshine. Among those groups and other darker-skinned individuals, low vitamin D should be considered a risk factor for dementia, they said. "Independent of race or ethnicity, baseline cognitive abilities and a host of other risk factors, vitamin D insufficiency was associated with significantly faster declines in both episodic memory and executive function performance," said Joshua Miller...

The large, longitudinal study was conducted in nearly 400 racially and ethnically diverse men and women in Northern California participating in longitudinal research at the Alzheimer's Disease Center in Sacramento, Calif. Fifty percent of participants were Caucasian and 50 percent were African-American or Hispanic. The participants had a mean age of 76 and were either cognitively normal, had mild cognitive impairment, or dementia.The participants' serum vitamin D status was measured at the beginning of the study.... Overall, 26 percent were deficient and 35 percent were insufficient. Among Caucasians, 54 percent had low vitamin D, compared with 70 percent of African-Americans and Hispanics.

Over five years of follow-up, vitamin D deficient individuals experienced cognitive declines that were two-to-three times faster than those with adequate serum vitamin D levels. In other words it took only two years for the deficient individuals to decline as much as their counterparts with adequate Vitamin D declined during the five-year follow-up period.

Exposing the skin to sunlight is the major source of vitamin D. Racial and some ethnic minorities are at greater risk of low vitamin D because the higher concentration of melanin that makes their skin darker -- and protects against skin cancer in sunny climates -- also inhibits synthesis of vitamin D. Diet is the other major source of vitamin D. Dietary vitamin D is obtained particularly through dairy consumption. The intake of dairy products is especially low among minority groups, with only 6.5 percent of African-Americans and 11 percent of Mexican-Americans nationwide consuming the recommended three daily servings of dairy products, the study says.