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The prestigious medical journal The Lancet recently released a report by its Commission On Pollution and Health on the effects of various types of pollution (water, air, occupational, chemical, etc) on people and world economies - that is, the effect of pollution on "global health". The main finding: Diseases caused by pollution were responsible in 2015 for an estimated 9 million premature deaths -- 16 percent of all deaths worldwide. Pollution is now known to cause a wide variety of diseases and health problems, including asthma, cancer, neurodevelopmental disorders, and birth defects in children; and heart disease, stroke, chronic obstructive pulmonary disease, and cancer in adults. The list of health effects keeps increasing. [See all posts on pollution.]

The report states that certain types of pollution are increasing throughout the world - air, chemical, and soil pollution.They also discuss new and emerging pollutants (most of them chemical pollutants) whose effects on human health
are not yet fully understood, yet they are widely found in the environment and detected in most humans. The authors of the report even say: "At least some of these chemical pollutants appear to have potential to cause global epidemics of disease, disability, and death."

Chemical pollutants include: developmental neurotoxicants (e.g. pesticides, lead, mercury), endocrine disruptors (which have reproductive effects and can alter fertility), new classes of pesticides such as the neonicotinoids, chemical herbicides such as glyphosate (found in Roundup and the most commonly used pesticide in the world), nano-particles, and pharmaceutical wastes.

While most deaths from all sorts of pollution are currently occurring in poorer developing countries (e.g. China and India), we in the United States also have health effects and deaths from pollution - just not on the scale of those countries. Also, remember that winds carry pollutants globally - so that air pollution in China will cross the Pacific Ocean on the winds to the US.

Everyone agrees that taking action works - think of the success in banning lead, asbestos, and DDT in the United States. And amounts of six common air pollutants have been reduced by about 70% since passage of the Clean Air Act in 1970. We can thank laws, and organizations established due to environmental problems and crises in the past (e.g. the Environmental Protection Agency (EPA), Superfund legislation, Clean Water Act, Clean Air Act) for that.

From Science Daily: Pollution responsible for 16 percent of early deaths globally

Diseases caused by pollution were responsible in 2015 for an estimated 9 million premature deaths -- 16 percent of all deaths worldwide, according to a report. Simon Fraser University health sciences professor Bruce Lanphear is a Commissioner and author of The Lancet Commission on Pollution and Health that has released a report detailing the adverse effects of pollution on global health. ...."Pollution, which is at the root of many diseases and disorders that plague humankind, is entirely preventable." 

Commission findings include: - Pollution causes 16% of all deaths globally. Diseases caused by pollution were responsible in 2015 for an estimated 9 million premature deaths -- 16% of all deaths worldwide -- three times more deaths than AIDS, tuberculosis, and malaria combined; and fifteen times more than all wars and other forms of violence. It kills more people than smoking, hunger and natural disasters. In some countries, it accounts for one in four deaths. - Pollution disproportionately kills the poor and the vulnerable. Nearly 92% of pollution-related deaths occur in low- and middle-income countries. Within countries, pollution's toll is greatest in poor and marginalized communities. Children face the highest risks because small exposures to chemicals in utero and in early childhood can result in lifelong disease and, disability, premature death, as well as reduced learning and earning potential. - Pollution is closely tied to climate change and biodiversity. Fossil fuel combustion in higher-income countries and the burning of biomass in lower-income countries accounts for 85% of airborne particulate pollution. Major emitters of carbon dioxide are coal-fired power plants, chemical producers, mining operations, and vehicles.

A few excerpts (lead & pesticides) from the report in The Lancet: The Lancet Commission on pollution and health

Another example of the economic benefits of addressing pollution is seen in the consequences of removing lead from gasoline in the USA. This intervention began in 1975 and, within a decade, had reduced the mean blood concentration of lead in the population by more than 90%, almost eliminated childhood lead poisoning, and increased the cognitive capacity of all American children born since 1980 by 2–5 IQ points. This gain in intelligence has increased national economic productivity and will yield an economic benefit of US$200 billion (range $110 billion–300 billion) over the lifetimes of each annual cohort of children born since 1980, an aggregate benefit to-date of over $6 trillion.

Developmental neurotoxicants: Evidence is strong that widely used chemicals and pesticides have been responsible for injury to the brains of millions of children and have resulted in a global pandemic of neurodevelopmental toxicity. The manifestations of exposure to these chemicals during early development include loss of cognition, shortening of attention span, impairment of executive function, behavioural disorders, increased prevalence of attention deficit and hyperactivity disorder, learning disabilities, dyslexia, and autism.

Pesticides: More than 20,000 commercial pesticide products, including insecticides, herbicides, fungicides, and rodenticides are available on world markets. More than 1.1 billion pounds of these products are used in the USA each year and an estimated 5.2 billion pounds globally. ....The organophosphate insecticides are a large and widely used class of pesticides. Members of this class of chemicals are powerful developmental neurotoxicantsand prenatal exposures are associated with persistent deleterious effects on children’s cognitive and behavioural function and with long-term, potentially irreversible, changes to brain structure that are evident on MRI. 

Chemical herbicides account for nearly 40% of global pesticide use and applications are increasing. A major use is in production of genetically modified food crops engineered to be resistant to glyphosate (Roundup), the world’s most widely used herbicide. Glyphosate-resistant, so-called “Roundup Ready” crops, now account for more than 90% of all corn and soybeans planted in the USA, and their use is growing globally. Glyphosate is widely detected in air and water in agricultural areas, and glyphosate residues are detected in commonly consumed foods.

The following is a nice article about a recently published study finding a link between some bacteria commonly found in the mouth and inflammatory bowel diseases (IBD). The researchers found that some strains of oral bacteria are also found in the gut of people with inflammatory bowel diseases.

They theorize that these bacteria make it down to the gut when saliva is swallowed - and for susceptible people this may trigger inflammatory disease. They did a number of experiments to determine that the antibiotic-resistant, inflammation causing species of Klebsiella pneumoniae and Klebsiella aeromobilis could be triggering IBD. These bacteria are able to replace normal colon microbes after antibiotic therapy.

However, it must be noted that other studies also find other microbial differences among those with IBD and healthy people - e.g. low or absent levels of Faecalibacterium prausnitzii, and even fungal and viral differences. From Harvard Magazine:

Gut Health May Begin in the Mouth

Chronic gastrointestinal problems may begin with what is in a patient’s mouth. In a study published Thursday in Science, an international team of researchers—including one from Harvard—reported on strains of oral bacteria that, when swallowed in the 1.5 liters of saliva that people ingest every day, can lodge in the gut and trigger inflammatory bowel conditions like Crohn’s disease and ulcerative colitis.

“For some time now, we’ve noticed that when we look at the microbiome of patients with inflammatory bowel disease, or IBD, we’ve found microbes there that normally reside in the oral cavity,” says study co-author Ramnik Xavier, chief of gastroenterology at Massachusetts General Hospital (MGH)....

Simultaneously, “There’s always been this other search, asking, ‘Are there pathobionts?’”—in other words, microbes that live innocuously in one part of the body but can turn pathogenic when moved to another. “For some time we have been looking for pathobiont organisms for Crohn’s and colitis.”

The researchers believe they have found them: two strains of Klebsiella bacteria, microbes commonly found in the mouth. ....the researchers pinpointed a strain of Klebsiella pneumoniae as the trigger for the immune response. A subsequent experiment using samples from two ulcerative colitis patients turned up another inflammation-causing strain, of Klebsiella aeromobilis

Checking databases of thousands of IBD patients at MGH and the Hospital of the University of Pennsylvania, Xavier and others found that people with inflammatory bowel conditions had significantly more Klebsiella bacteria in their gut microbiome than healthy patients did. Most likely, he explains, oral bacteria, including Klebsiella, traffics through everyone’s gut in the saliva we swallow. Usually it passes through harmlessly; but in people with a genetic susceptibility to IBD that alters the gut microbiome, the Klebsiella has a chance to take hold in the intestine and proliferate, inducing an immune response that causes the disease. 

And there is another twist: Klebsiella bacteria are often extremely resistant to multiple antibiotics. That explains, Xavier says, “why antibiotics have limited value in treating patients with Crohn’s disease and ulcerative colitis....  “Because we also showed in a 2014 paper that patients who took antibiotics—and this has been seen in the old clinical data accumulated before the microbiome was even examined in IBD—that patients who took antibiotics early in the disease had more complicated outcomes.” 

Klebsiella  pneumoniae Credit: Wikipedia

Once again the controversial herbicide (weed killer) glyphosate is in the news. Glyphosate is the active ingredient in Roundup (manufactured by Monsanto), and is the most commonly used pesticide in the world. Its use is increasing annually since the introduction of genetically modified crops that are tolerant of glyphosate being sprayed on them (Roundup Ready crops), and since the use of "preharvest" applications of Roundup. Over the years the US government has generally NOT been tracking how much glyphosate residues are in the foods we eat, but whenever a food is studied for glyphosate residues - they are found. (see all posts) Which means people are constantly ingesting low levels of glyphosate residues.

But what does that mean for humans? A  recently published study of 100 adults over the age of 50, residing in Southern California, and followed from 1993 to 2016, looked at detectable glyphosate and its metabolite aminomethylphosphonic acid (AMPA) residues in urine. They found that the number of people with detectable residues in urine, and also the actual levels found in the urine, really, really increased in the 23 years. The percentage of people who tested positive for glyphosate shot up by 500% in that time period - from 12 percent of the samples to 70 percent. WOW!

Are there health effects from constant ingestion in food from low levels of glyphosate? We don't know, because the studies on humans have not been done. There are a number of health concerns, including that it is a carcinogen (it has been classified as a "probable carcinogen" by some agencies), liver and kidney damage, that it acts as an antibiotic and disrupts the gut microbiome, and endocrine disruption. The researchers of this study are especially concerned about possible glyphosate health effects on the liver (liver disease), based on animal studies (animals exposed chronically to very low levels), and want to research this further.

However, the EPA keeps insisting it's safe (and to please ignore the conflicts and deals done with Monsanto in recent years), and actually raised the levels allowed in 2013 (due to corporate lobbying). Also, glyphosate is still not monitored by the Department of Agriculture's pesticide data program or the CDC's (Centers for Disease Control and Prevention) monitoring program of human exposure to environmental chemicals.

What can you do? Try to eat as many organic foods as possible because glyphosate (and Roundup) are not allowed to be used in organic farming. And don't use Roundup on your own property - because you can be exposed to it numerous ways (drinking and eating it in food, inhalation, through the skin).

From Medical Xpress: US study finds rise in human glyphosate levels

Levels of glyphosate, a controversial chemical found in herbicides, markedly increased in the bodies of a sample population over two decades, a study published Tuesday in a US medical journal said. The increase dated from the introduction of genetically-modified glyphosate-tolerant crops in the United States in 1994.

Researchers compared the levels of glyphosate in the urine of 100 people living in California. It covered a 23-year period starting from 1993, the year before the introduction of genetically-modified crops tolerant to Roundup. Glyphosate-containing Roundup, produced by US agro giant Monsanto, is one of the world's most widely-used weedkillers.

"Prior to the introduction of genetically modified foods, very few people had detectable levels of glyphosate," said Paul Mills, of the University of California at San Diego School of Medicine, the study's principal author. Among the study group, detectable amounts increased from an average of 0.20 micrograms per liter in 1993-1996 to an average of 0.45 micrograms in 2014-2016.

In July, California listed glyphosate as carcinogenic, and the World Health Organization International Agency for Research on Cancer called it "probably carcinogenic" in 2015. There are few human studies on the effects of glyphosate, but research on animals demonstrated that chronic exposure can have adverse effects, said Mills. Along with the European Commission's proposal on Tuesday, the European Parliament approved a non-binding resolution calling for the chemical to be banned by 2022.

Excerpts from Consumer Reports: We May Be Consuming More Glyphosate Than Ever Before

A 2016 report in the journal Environmental Health that looked at human and animal studies found a link between glyphosate exposure and a number of health problems, including liver and kidney damage, endocrine disruption, and an elevated risk of non-Hodgkin’s lymphoma. But a vast majority of those studies were done with animals.

In fact, very few human studies have been done on the health effects of glyphosate, and no federal agency monitors how much of the chemical makes it from the environment into our bodies. That lack of information makes it difficult to even begin to assess how much glyphosate is potentially harmful to humans and whether current exposure levels are above or below that mark.

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Another interesting theory about dyslexia, as well as a great treatment possibility. It is unknown if the study results will hold up with more research (after all, only 60 people were in the study - 30 with dyslexia and 30 without), and whether their suggested treatment really works for larger groups of dyslexics. But what if it helps?

Their main finding is that those who don't have dyslexia have  "asymmetry" in the light-receptor cells in the center of the eye, while dyslexics have symmetry which leads to the brain producing confusing mirror images of letters (e.g."b" and "d"). The researchers conclude that: "the lack of asymmetry might be the biological and anatomical basis of reading and spelling disabilities in people with a normal ocular status but with dyslexia". They found that a flashing LED lamp ("pulse-width modulation light-emitting diode") suppressed the mirror images in those with dyslexia and they could read normally ("restores reading skills"). So this research is definitely worth following. From Medical Xpress:

Scientists may have found a cause of dyslexia

A duo of French scientists said Wednesday they may have found a physiological, and seemingly treatable, cause for dyslexia hidden in tiny light-receptor cells in the human eye. In people with the reading disability, the cells were arranged in matching patterns in both eyes, which may be to blame for confusing the brain by producing "mirror" images, the co-authors wrote in the journal Proceedings of the Royal Society B. In non-dyslexic people, the cells are arranged asymmetrically, allowing signals from the one eye to be overridden by the other to create a single image in the brain.

It offers a "relatively simple" method of diagnosis, he added, by simply looking into a subject's eyes. Furthermore, "the discovery of a delay (of about 10 thousandths of a second) between the primary image and the mirror image in the opposing hemispheres of the brain, allowed us to develop a method to erase the mirror image that is so confusing for dyslexic people"—using an LED lamp.

Like being left- or right-handed, human beings also have a dominant eye. As most of us have two eyes, which record slightly different versions of the same image, the brain has to select one of the two, creating a "non-symmetry." Many more people are right-eyed than left, and the dominant eye has more neural connections to the brain than the weaker one. Image signals are captured with rods and cones in the eye—the cones being responsible for colour. The majority of cones, which come in red, green and blue variants, are found in a small spot at the centre of the cornea of the eye known as the fovea. But there is a small hole (about 0.1-0.15 millimetres in diameter) with no blue cones.

In the new study, Ropars and colleague Albert le Floch spotted a major difference between the arrangement of cones between the eyes of dyslexic and non-dyslexic people enrolled in an experiment. In non-dyslexic people, the blue cone-free spot in one eye—the dominant one, was round and in the other eye unevenly shaped. In dyslexic people, both eyes have the same, round spot, which translates into neither eye being dominant, they found.

Dyslexic people make so-called "mirror errors" in reading, for example confusing the letters "b" and "d". ....The team used an LED lamp, flashing so fast that it is invisible to the naked eye, to "cancel" one of the images in the brains of dyslexic trial participants while reading. In initial experiments, dyslexic study participants called it the "magic lamp," said Ropars, but further tests are required to confirm the technique really works. [Original study.]

 

Cross-section of the human eye. Credit: Wikipedia

Dr. John Mandrola again has a great blog post over at his site and at Medscape. The post is about how employed doctors nowadays are evaluated by a "measure of productivity" - called the relative value unit or RVU. This means one gets a higher score of productivity from the number of procedures done on patients, rather than listening and counseling patients, or reading medical studies or doing medical research.

Which is the opposite of how medical care should be. Also look at the comments after the post. From Dr. John M:

A Corrosive Force in Medical Care

It comes in a large white envelope each month. It’s marked confidential. When I hold it up to the light, I can see through the envelope. I can’t see the details, but the colored graphs give it away. It’s my monthly productivity report. Most employed doctors get these graphs.

These “dashboards” of value include your own productivity as well as many graphs on how you stack up with other doctors across the country. It shows your employer if you are a hard worker. The measure of productivity we use is called the relative value unit or RVU.

Doing an ablation, cath, stent or valve replacement earns a bunch of RVUs. Listening to patients, examining patients, counseling patients, hugging patients earns very few RVUs. Doing important research, teaching colleagues, and reading the medical evidence earns zero RVUs.

Too often, in too many medical systems, RVUs have become the primary unit of success. No, you can’t be a mean and nasty doctor. And no, you can’t be a totally unskilled doctor who has too many complications. But short of those extremes, if you make few waves, have good templates on your electronic health record so documentation is complete, and do tons of procedures, you are valuable.

If, on the other hand, you like slow conservative medicine, or narrative notes rather than templates, or worse, if you are thoughtful and frank about silly policies, you become an outlier. If you do these things, your RVU tally usually does not reach the 75% of standard. Then trouble can come to you.

What’s really scary, though, is that this is the milieu in which a younger generation is learning the craft. I was shocked to learn that a major teaching center (will remain nameless) has its teaching faculty on 100% productivity compensation. Imagine that. Teachers of young people whose paychecks are determined by how many RVUs they generate. This, my friends, is happening in many of the places you go to get health care.... Productivity and the RVU has no place in medical care. There needs to be a different system of valuing the care of people with disease.

I can't resist posting excerpts from a recent article announcing that researchers just found an entirely new lymph system ("lymphatic vessels") in the brain that transports fluid in the brain, and is probably "crucial to metabolic and inflammatory processes".  The image in this post shows the system in the brain. Amazing that it is only now "discovered" - apparently it was noticed by an anatomist 2 centuries ago, but this was pooh-poohed by modern day physicians. Until now. Excerpts from the Atlantic:

Scientists Somehow Just Discovered a New System of Vessels in Our Brains

You are now among the first people to see the brain’s lymphatic system. The vessels in the photo above transport fluid that is likely crucial to metabolic and inflammatory processes. Until now, no one knew for sure that they existed. Doctors practicing today have been taught that there are no lymphatic vessels inside the skull. Those deep-purple vessels were seen for the first time in images published this week by researchers at the U.S. National Institute of Neurological Disorders and Stroke.

In the rest of the body, the lymphatic system collects and drains the fluid that bathes our cells, in the process exporting their waste. It also serves as a conduit for immune cells, which go out into the body looking for adversaries and learning how to distinguish self from other, and then travel back to lymph nodes and organs through lymphatic vessels.

Senior investigator Daniel Reich trained as both a neurologist and radiologist, and his expertise is in inflammatory brain disease. The connection between the immune system and the brain is at the core of what he says he spends most of his time thinking about: multiple sclerosis. The immune system appears to modulate or even underlie many neurologic diseases, and the cells of the central nervous system produce waste that needs to be washed away just like other metabolically active cells. This discovery should make it possible to study how the brain does that, how it circulates white blood cells, and how these processes may go awry in diseases or play a role in aging.

Around the same time, researchers discovered fluid in the brains of mice and humans that would become known as the “glymphatic system.” It was described by a team at the University of Rochester in 2015 as not just the brain’s “waste-clearance system,” but as potentially helping fuel thebrain by transporting glucose, lipids, amino acids, and neurotransmitters.

Wouldn’t neurosurgeons, at some point in their meticulous down-to-the-millimeter dissecting of brains, have stopped and said, “Hey ... what’s this thing?”The lymph vessels probably escaped detection because they’re inside a thick membrane, the dura mater, which is the consistency of leather. They run alongside blood vessels that are much larger, and on MRI the signal that creates the images is dominated by the blood vessels.  

But this pathway appears crucial to life and health. A 2013 study in Science found that glymphatic flow seems to increase by almost double during sleep (in mice). Sleep disturbances are a common feature in Alzheimer’s and other neurologic disorders, and it’s possible that inadequate clearing of the brain’s waste products is related to exacerbating or even causing the disease.... 

The flow of glymphatic fluid can change based on a person’s intake of omega-3 fatty acids, a study showed earlier this year. Preliminary findings like these together suggest a pathway through which nutrition and sleep can be related to neurologic disorders. Optimizing this glymphatic flow could become a central theme for the future of neurologic health. “If all of this is true, there probably is a connection between these two systems, glymphatic and lymphatic,” Reich said. “And that would be one of the major functions of cerebrospinal fluid.”

From The Atlantic. Credit: Daniel Reich/ National Institute of Neurological Disorders and Stroke

For years studies have suggested that eating blueberries and other berries is good for our health (here, here, and here). Now another study suggests that eating wild blueberries benefits children's thinking, specifically attention and "executive function" (mental processes which lets people plan, organize, and complete tasks). What was nice in this study was that it was "double-blind"- which meant that biases couldn't influence the results. 

Flavonoids are a diverse group of phytonutrients (plant chemicals) found in almost all fruits and vegetables. They are powerful antioxidants with anti-inflammatory and immune system benefits. And yes, other studies have also found various benefits to mental processes with an increase of flavonoids in the diet - in both children and adults.

What foods contain flavonoids? There are 6 main classes of flavonoids, and each is found in different foods: - Anthocyanidins – found in red, purple,and blue berries, red wine, and red and purple grapes. - Flavonols - found in onions, leeks, broccoli, Brussels sprouts, kale, tea, berries, beans, and apples. - Flavones - found in parsley, celery, and hot peppers. - Isoflavones - found in soybeans, soy products, and legumes. - Flavanones - found in citrus fruit and tomatoes. - Flavanols - found in tea, red wine, grapes, apples, fava beans, and cocoa. From Medical Xpress:

Primary school children could show better attention by consuming flavonoid-rich blueberries, following a study conducted by the University of Reading. In a paper published in Food & Function, a group of 7-10 year olds who consumed a drink containing wild blueberries or a matched placebo and were tested on their speed and accuracy in completing an executive task function on a computer.The double blind trial found that the children who consumed the flavonoid-rich blueberry drink had 9% quicker reaction times on the test without any sacrifice of accuracy. In particular, the effect was more noticeable as the tests got harder.

Previous [Univ. of] Reading research has shown that consuming wild blueberries can improve mood in children and young people, simple memory recall in primary school children, and that other flavonoid rich drinks such as orange juice, can also improve memory and concentration.

Wild blueberries are grown and harvested in North America, and are smaller than regular blueberries, and are higher in flavonoids compared to regular varieties. The double-blind trial used a flavonoid-rich wild blueberry drink, with a matched placebo contained 8.9 g of fructose, 7.99 g of glucose and 4 mg of vitamin C matching the levels of nutrients found in the blueberry drink. [Original study.] 

The following study looked at genes and longevity. Researchers from the University of Edinburgh analysed genetic information from more than 600,000 people along with records of their parents' lifespan.

They found that the following factors were correlated with longevity: not smoking or giving up smoking, a higher educational attainment, openness to new experiences, and good cholesterol levels. On the other hand, the following factors were correlated with reduced longevity ("were negatively correlated"): genetic susceptibility to coronary artery disease (CAD), smoking, lung cancer, diabetes, and higher body fat. For example, 1 year of education adds 11 months to expected lifespan, and gaining weight reduces life-span (lose 2 months for every 2.2 lbs extra weight), while losing extra weight increases it. From Science Daily:

Learning and staying in shape key to longer lifespan, study finds

People who are overweight cut their life expectancy by two months for every extra kilogramme [2.2 lbs.] of weight they carry, research suggests. A major study of the genes that underpin longevity has also found that education leads to a longer life, with almost a year added for each year spent studying beyond schoolOther key findings are that people who give up smoking, study for longer and are open to new experiences might expect to live longer.

Scientists at the University of Edinburgh analysed genetic information from more than 600,000 people alongside records of their parents' lifespan. Because people share half of their genetic information with each of their parents, the team were able to calculate the impact of various genes on life expectancy. Lifestyle choices are influenced to a certain extent by our DNA -- genes, for example, have been linked to increased alcohol consumption and addiction. The researchers were therefore able to work out which have the greatest influence on lifespan.

They found that cigarette smoking and traits associated with lung cancer had the greatest impact on shortening lifespan. For example, smoking a packet of cigarettes per day over a lifetime knocks an average of seven years off life expectancy, they calculated. But smokers who give up can eventually expect to live as long as somebody who has never smoked. Body fat and other factors linked to diabetes also have a negative influence on life expectancy.

The study also identified two new DNA differences that affect lifespan. The first -- in a gene that affects blood cholesterol levels -- reduces lifespan by around eight months. The second -- in a gene linked to the immune system -- adds around half a year to life expectancy. Data was drawn from 25 separate population studies from Europe, Australia and North America, including the UK Biobank -- a major study into the role of genetics and lifestyle in health and disease.  [Original study.]

A number of recent studies have suggested that as people age, the community of gut microbes (gut microbiota or gut microbiome) becomes less diverse than in younger people. And note that greater gut microbial diversity is generally viewed as healthy and good. However, now a study done in China finds a different result. The study examined the gut microbes of more than 1000 very healthy people, from ages 3 to over 100, and found that the gut microbial communities were very similar among very healthy people in their mid 30s to over 100 years in age.

Whether this is cause or effect is unknown. But the researchers speculate that the similarities in the gut microbiota among people from their 30s to 100+ is a consequence of an active healthy lifestyle and diet. And it suggests that somehow changing an elderly person's gut microbial community (if it's not "normal") to that of a 30-year-old might help promote health. From Science Daily:

'Ridiculously healthy' elderly have the same gut microbiome as healthy 30-year-olds

In one of the largest microbiota studies conducted in humans, researchers at Western University, Lawson Health Research Institute and Tianyi Health Science Institute in Zhenjiang, Jiangsu, China have shown a potential link between healthy aging and a healthy gut.

With the establishment of the China-Canada Institute, the researchers studied the gut bacteria in a cohort of more than 1,000 Chinese individuals in a variety of age-ranges from 3 to over 100 years-old who were self-selected to be extremely healthy with no known health issues and no family history of disease. The results showed a direct correlation between health and the microbes in the intestine. ....The study, published this month in the journal mSphere, showed that the overall microbiota composition of the healthy elderly group was similar to that of people decades younger, and that the gut microbiota differed little between individuals from the ages of 30 to over 100.

"The main conclusion is that if you are ridiculously healthy and 90 years old, your gut microbiota is not that different from a healthy 30 year old in the same population," said Greg Gloor, the principal investigator on the study and also a professor at Western's Schulich School of Medicine & Dentistry and Scientist at Lawson Health Research Institute. Whether this is cause or effect is unknown, but the study authors point out that it is the diversity of the gut microbiota that remained the same through their study group.

"This demonstrates that maintaining diversity of your gut as you age is a biomarker of healthy aging, just like low-cholesterol is a biomarker of a healthy circulatory system," Gloor said. The researchers suggest that resetting an elderly microbiota to that of a 30-year-old might help promote health. "By studying healthy people, we hope to know what we are striving for when people get sick," said Reid. [Original study.]

Centenarian in Bama County, China. Credit: National Geographic.

Interesting study finding - that both high and low levels of magnesium is associated with a higher risk of dementia. Magnesium is an essential mineral needed for more than 300 biochemical reactions in the body. According to a large study done in the Netherlands of people who were followed for about 8 years - there was a U-shaped incidence of dementia based on their levels of magnesium. The lowest incidence was in those with "in the middle" normal levels of magnesium in the blood. All the study participants were mentally healthy when the study started.

The researchers stated that magnesium levels are considered "relatively stable over time", but a limitation of the study is that they only looked at magnesium levels once - at the beginning of the study, so they could have changed over time. Of course further studies are needed. [Other posts on magnesium and health - here, here, and here.]

Magnesium is widely available in foods. Foods that are good sources of magnesium include: spinach and other dark green leafy vegetables, almonds, cashews, peanuts, bananas, soybeans, kidney and black beans (legumes), whole grains, lentils, seeds, yogurt, brown rice, potatoes, and avocados. It is recommended that magnesium is obtained from the diet, and not from supplements (due to health risks from high doses). From Science Daily:

Both high, low levels of magnesium in blood linked to risk of dementia

People with both high and low levels of magnesium in their blood may have a greater risk of developing dementia, according to a study published in the September 20, 2017, online issue of Neurology®, the medical journal of the American Academy of Neurology.

The study involved 9,569 people with an average age of 65 who did not have dementia whose blood was tested for magnesium levels. The participants were followed for an average of eight years. During that time, 823 people were diagnosed with dementia. Of those, 662 people had Alzheimer's disease. The participants were divided into five groups based on their magnesium levels. Both those with the highest and the lowest levels of magnesium had an increased risk of dementia, compared to those in the middle group.

Both the low and high groups were about 30 percent more likely to develop dementia than those in the middle group. Of the 1,771 people in the low magnesium group, 160 people developed dementia, which is a rate of 10.2 per 1,000 person-years. For the high magnesium group, 179 of the 1,748 people developed dementia, for a rate of 11.4 per 1,000 person-years. For the middle group, 102 of the 1,387 people developed dementia, for a rate of 7.8. Kieboom noted that almost all of the participants had magnesium levels in the normal range, with only 108 people with levels below normal and two people with levels above normal[Original study.]