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Author: Sima

Published on Leave a comment on Definitely Increase Fiber Intake After A Colon Cancer Diagnosis

A recent study found that significantly increasing  dietary fiber intake after a diagnosis of colorectal cancer was associated with a lower death rate - from both colorectal cancer and overall mortality (from any cause). The 1575 men and women (all healthcare professionals) in the study had received a nonmetastatic colorectal cancer diagnosis (it had not spread beyond the colon), and the follow-up was about 8 years. These results were from food, not supplements.

How much did extra dietary fiber lower the death rate? For each additional 5  grams of fiber added to their daily diet (after diagnosis) was associated with a 18% lower colorectal cancer death rate, and a 14% lower death rate from any cause. In this study, whole grains, especially in cereals, were found to be the most beneficial. Current dietary guidelines recommend a fiber intake of 25 to 38 grams per day, but most Americans eat far less. Dietary fiber is found in plant foods, such as beans, whole grains, nuts, seeds,  vegetables, and fruits. Plant fiber feeds the millions of gut microbes, especially beneficial microbes (here, here, and here) - something that was not really discussed in the study.

The researchers pointed out that a high fiber diet (especially from whole grains and cereals) is linked to a lower risk of getting colorectal (colon) cancer in the first place.  Also, that "higher intake of fiber, especially cereal fiber", has been linked to improved insulin sensitivity, reduced inflammation, type 2 diabetes, cardiovascular disease, and total mortality. Other studies have found that  vitamin D supplementation, exercise, and eating fish all increase survival from colorectal cancer. From From Medical Xpress:

Fiber-rich diet boosts survival from colon cancer

A diet rich in fiber may lessen the chances of dying from colon cancer, a new study suggests. Among people treated for non-metastatic colon cancer, every 5 grams of fiber added to their diet reduced their odds of dying by nearly 25 percent, said lead researcher Dr. Andrew Chan. He is an associate professor in the department of medicine at Harvard Medical School.

"What you eat after you've been diagnosed may make a difference," Chan said. "There is a possibility that increasing your intake of fiber may actually lower the rate of dying from colon cancer and maybe even other causes." Chan cautioned, however, that the study does not prove that the additional fiber caused people to live longer, only that the two were associated.

Fiber has been linked to better insulin control and less inflammation, which may account for better survival, he suggested. In addition, a high-fiber diet may protect people from developing colon cancer in the first place. The greatest benefit was attributed to fiber from cereals and whole grains, according to the report. Vegetable fiber was linked to an overall reduction in death, but not specifically in death from colon cancer, and fiber from fruit was not linked to a reduction in death from any cause. 

For the study, Chan and his colleagues collected data on 1,575 men and women who took part in the Nurses' Health Study and Health Professionals Follow-up Study, and who had been treated for colon or rectal cancer that had not spread beyond the colon. Specifically, the study looked at total fiber consumption in the six months to four years after the participants' cancer diagnosis. The researchers also looked at deaths from colon cancer and any other cause. In an eight-year period, 773 participants died, including 174 from colorectal cancer. [Original study.]

Published on Leave a comment on Health Benefits Of Eating Whole Grains

Another study has shown health benefits from eating a diet rich in whole grains, as compared to one with lots of refined grains (think bagels, muffins, white bread). Fifty overweight Danish adults were randomly assigned to either a group where all grains eaten were whole grains or a group where all grain products were of refined grains. They did this for 8 weeks, then ate their usual diet for a few weeks (the "washout period"), and then were assigned to the other dietary group for 8 weeks.

They found that eating the diet rich in whole grains resulted in: consuming fewer calories (the whole grains made them feel fuller), losing weight, and a decrease in chronic low-grade inflammation (by measuring blood inflammation markers). The whole grain rye seemed to be especially beneficial. But interestingly, the researchers found that the whole grain diet did not significantly change the gut microbe composition. But they did find that 4 strains of Faecalibacterium prausntzii and one of Prevotella copri increased in abundance after whole grain and decreased after refined grain consumption. F.prausnitzii is a desirable and beneficial keystone species in the gut (here and here).

Other studies show that eating a diet rich in whole grains (rather than refined grains) is associated with a decreased risk of several diseases, including type 2 diabetes and cardiovascular diseases. Bottom line: choose whole grains whenever possible. From Science Daily:

Several reasons why whole grains are healthy

When overweight adults exchange refined grain products -- such as white bread and pasta -- with whole grain varieties, they eat less, they lose weight and the amount of inflammation in their bodies decreases. These are some of the findings of a large Danish study headed by the National Food Institute, Technical University of Denmark. 

The study included 50 adults at risk of developing cardiovascular disease or type 2 diabetes. Blood tests showed that the participants had less inflammation in their bodies when eating whole grains. In particular, it appeared that rye had a beneficial effect on the blood's content of inflammatory markers. Inflammation is the natural response of the body to an infection, but some people have slightly elevated levels of inflammation (so-called low-grade inflammation) even though there is no infection. This is particularly the case in overweight people. In overweight people, an increased level of 'unnecessary' (subclinical) inflammation may lead to increased risk of developing type 2 diabetes.

The study also shows that participants eat less when whole grain products are on the menu -- presumably because whole grain consumption causes satiety. While eating the whole grain diet, participants have generally lost weight. The researchers used DNA sequencing to analyze stool samples from the participants in order to examine whether the different diet types affected the participants' gut bacteria composition. Overall, the analysis did not shown major effects of the dietary grain products on the composition of the gut bacteria. [Original study.]

Published on Leave a comment on Group Recommends Against Vaginal Seeding

A while ago I posted the results of studies showing differences in infant  microbiomes (community of microbes) depending on whether the babies were delivered vaginally or by C-section, and also that "vaginal seeding" may eliminate some of these differences. [C-section babies also have a higher incidence of some health issues, such as allergies, asthma, etc.] Well....that research generated a lot of controversy both for and against, and resulted in many women requesting that "vaginal seeding" be done to their babies after they were delivered by C-section. Even the noted microbiome researcher Rob Knight publicly admitted that the procedure was done to his baby after his partner received a C-section.

Vaginal seeding is the process of swabbing the bodies of C-section babies (including the mouth and nose) with a gauze pad containing the vaginal fluids from their mothers in the minutes after birth - so that the baby is exposed to the same maternal microbes as a baby born vaginally (because mothers transmit microbes to the baby as it moves through the birth canal). Initial research showed this made the microbiomes of the C-section babies look a lot like vaginally born babies, especially their skin and oral microbiomes, but whether these differences persist after a few months is unclear.

Now the American College of Obstetrics and Gynecology (ACOG) has come out with a position paper that vaginal seeding should not be done to babies, except as part of an official clinical trial. Their main opposition to the procedure is fear of transmitting pathogenic bacteria or viruses (e.g. group B streptococci, and STDs). The main reasons in support of doing the  vaginal seeding procedure is the body of research finding differences among C-section and vaginally delivered babies (allergies, asthma, etc.), and the concern that at least some of this may be due to lack of  exposure to maternal vaginal microbes during delivery. Instead, ACOG suggests breastfeeding the baby to transmit maternal microbes to the baby to "seed the gut". And if "a patient insists on performing the procedure herself, ACOG recommends ob-gyns have a documented discussion of the potential risks".

As can be expected, there is an outcry and rejection by some (many?) of the ACOG position paper. At least the ACOG paper acknowledges that every woman can make her own decision regarding this issue, even though they may not support it. And absolutely everyone agrees that more research is needed. From Ars Technica:

Doctors warn new parents: Step away from the vaginal fluid swabs

To slather, or not to slather—that is the question that has been roiling doctors, scientists, and new parents recently. And a new ruling by a doctor’s group stands to muck up the debate further. Amid the birth of microbiome research, some scientists have advocated for smearing bacteria-laden vaginal secretions on any newborns who missed out—namely those born via Caesarian section. Scientists keenly hypothesize that such a gooey glaze can “seed” a more-or-less sterile infant with life-long microbial companions. These wee chums may help train an infant's immune system and dodge issues like allergies and asthma later in life. Several studies have indeed found correlations between C-section deliveries and higher risks of those conditions.

In the latest turn to the controversy, the American College of Obstetricians and Gynecologists’ (ACOG) Committee on Obstetric Practice issued a November opinion firmly wiping up the slimy idea. In its opinion, the committee said it: “…does not recommend or encourage vaginal seeding outside of the context of an institutional review board-approved research protocol, and it is recommended that vaginal seeding otherwise not be performed until adequate data regarding the safety and benefit of the process become available.”

The few studies we do have on infant microbiomes provide no clear answers on the significance of an early “seeding” for health. A 2016 review looking at the patterns of microbial communities in the guts of infants in their first year found that C-section babies did show differences in the first three months. However, those differences disappeared by six months. Similarly, a small study of 18 babies also published last year found that vaginal seeding could eliminate microbial differences between vaginally and C-section delivered babies. But the study only looked at the infants' microbiomes in that first month, and the health effects—if any—are unknown.

The most concerning thing about vaginal seeding, the committee argues, is the potential for transmitting pathogens, such as herpes simplex virus, human papilloma virus (HPV), group B streptococci, and Neisseria gonorrhea. .... If a woman insists on the seeding, the committee recommended she be thoroughly tested and informed of the risks—as well as discouraged.

Published on Leave a comment on Exercise, Exercise, Exercise To Keep From Regaining Weight

So you finally lost weight by diligently dieting, but now the issue is how to keep the weight from creeping back up again. Keeping strict watch over what you eat (basically continuing to diet)? Or exercising? Or...? Another issue muddying the waters is that a big weight loss also lowers the metabolism rate - something that occurred to former participants of the reality TV show The Biggest Loser.

They lost enormous amounts of weight during the 30 week competition (over 100 pounds on average), but 6 years later much of the weight was regained, and they were burning hundreds fewer calories each day at rest. So they had become metabolically much slower over time.

A study looking at 14 former participants of The Biggest Loser 6 years after the show found that a large persistent increase in physical activity was essential for long-term maintenance of weight loss. Those who regained the least weight were the most active, and vice versa. On the other hand, food intake (keeping calorie intake low) wasn't the most important.

How much of an increase in physical activity was needed to maintain the weight loss? Researchers found that an increase of about 80 minutes of daily moderate activity (such as brisk walking) or 35 minutes of daily vigorous activity was needed. From Medscape:

The Biggest Loser: Physical Exertion Is Key to Keeping Weight Off

Persistent increased physical activity is likely essential for long-term maintenance of weight loss, new research from participants in the US TV reality show The Biggest Loser suggests.... Using objective measures for both energy intake and physical activity in 14 former Biggest Loser contestants 6 years after they participated in the competition, Dr Kerns and colleagues found that those who had regained the least weight were the most active, and vice versa. Food intake, on the other hand, had very little effect on long-term weight-loss maintenance.

Asked to comment, Eric Ravussin, PhD, Boyd Professor at Louisiana State University, Baton Rouge, and coeditor of Obesity, told Medscape Medical News that the data align with those of follow-ups to major trials — including the Diabetes Prevention Program and the Action for Health Diabetes (Look AHEAD) study as well as with the National Weight Control Registry — of thousands of people who have lost at least 30 pounds and kept them off for at least a year. "The successful losers…all report high levels of physical activity" for weight maintenance, in contrast to weight loss, for which caloric deficit plays a far greater role, Dr Ravussin noted.

The reason for the difference between what works for weight loss vs maintenance, he said, probably has a lot to do with metabolic adaptation. This was the subject of another Biggest Loser paper published in Obesity in 2016, in which a person's metabolism slows down in response to a large drop in weight, making weight-loss maintenance difficult without an extra "push" from exercise, he explained.

The subjects in the new study were 14 participants with class III obesity who participated in a single season of The Biggest Loser, during which they underwent an intensive 30-week diet and exercise program and lost an average of 60 kg. Most regained weight after the program ended, although the degree of regain was highly variable. The median weight loss after 6 years was 13%. Seven subjects above the median weighed 24.9% less than baseline (maintainers) while the seven below the line (regainers) weighed 1.1% above their baseline. The maintainers had significantly greater increases in physical activity from baseline compared with the regainers..... that 35 minutes a day of intensive exercise, or 80 minutes of moderate activity, would roughly approximate the calorie expenditures among the maintainers.

Published on Leave a comment on Pollution and Early Death

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 neurotoxicants, and 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.

Published on Leave a comment on Are Some Microbes Traveling from The Mouth to the Gut and Causing Problems?

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

Published on Leave a comment on How Much Glyphosate Is In You?

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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Published on 2 Comments on Is This A Cause of Dyslexia?

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

Published on Leave a comment on How Should Physicians Be Evaluated?

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.

Published on Leave a comment on System of Lymph Vessels Discovered In the Brain

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