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Category: brain

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Another study finding negative effects of air pollution - this time high levels of traffic-related air pollution is linked to slower cognitive development among 7 to 10 year old children in Barcelona, Spain. From Science Daily:

Air pollution linked to slower cognitive development in children

Attendance at schools exposed to high levels of traffic-related air pollution is linked to slower cognitive development among 7- to 10-year-old children in Barcelona, according to a new study.

The researchers measured three cognitive outcomes (working memory, superior working memory, and attentiveness) every 3 months over a 12-month period in 2715 primary school children attending 39 schools. By comparing the development of these cognitive outcomes in the children attending schools where exposure to air pollution was high to those children attending a school with a similar socio-economic index where exposure to pollution was low, they found that the increase in cognitive development over time among children attending highly polluted schools was less than among children attending paired lowly polluted schools, even after adjusting for additional factors that affect cognitive development.

Thus, for example, there was an 11.5% 12-month increase in working memory at the lowly polluted schools but only a 7.4% 12-month increase in working memory at the highly polluted schools. These results were confirmed using direct measurements of traffic related pollutants at schools.

The findings suggest that the developing brain may be vulnerable to traffic-related air pollution well into middle childhood, a conclusion that has implications for the design of air pollution regulations and for the location of new schools. While the authors controlled for socioeconomic factors, the accuracy of these findings may be limited by residual confounding, that is, the children attending schools where traffic-related pollution is high might have shared other unknown characteristics that affected their cognitive development.

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Long-term air pollution can cause damage to the brain: covert brain infarcts ("silent strokes") and smaller brain volume (equal to one year of brain aging).

The authors of a study looking at 900 men in the Boston area concluded that, on average, participants who lived in more polluted areas had the brain volume of someone 1 year older vs participants who lived in less polluted areas, and they also had a 46% higher risk for silent strokes. While the mechanisms of how air pollution may affect brain aging is unclear, the researchers think that inflammation resulting from the deposit of fine particles in the lungs is important. From Science Daily:

Long-term exposure to air pollution may pose risk to brain structure, cognitive functions

Air pollution, even at moderate levels, has long been recognized as a factor in raising the risk of stroke. A new study led by scientists from Beth Israel Deaconess Medical Center and Boston University School of Medicine suggests that long-term exposure can cause damage to brain structures and impair cognitive function in middle-aged and older adults. 

Writing in the May 2015 issue of Stroke, researchers who studied more than 900 participants of the Framingham Heart Study found evidence of smaller brain structure and of covert brain infarcts, a type of "silent" ischemic stroke resulting from a blockage in the blood vessels supplying the brain.

The study evaluated how far participants lived from major roadways and used satellite imagery to assess prolonged exposure to ambient fine particulate matter, particles with a diameter of 2.5 millionth of a meter, referred to as PM2.5. These particles come from a variety of sources, including power plants, factories, trucks and automobiles and the burning of wood. They can travel deeply into the lungs and have been associated in other studies with increased numbers of hospital admissions for cardiovascular events such as heart attacks and strokes.

Study participants were at least 60 years old and were free of dementia and stroke. The evaluation included total cerebral brain volume, a marker of age-associated brain atrophy; hippocampal volume, which reflect changes in the area of the brain that controls memory; white matter hyperintensity volume, which can be used as a measure of pathology and aging; and covert brain infarcts.

The study found that an increase of only 2µg per cubic meter in PM2.5, a range commonly observed across metropolitan regions in New England and New York, was associated with being more likely to have covert brain infarcts and smaller cerebral brain volume, equivalent to approximately one year of brain aging...."This is concerning since we know that silent strokes increase the risk of overt strokes and of developing dementia, walking problems and depression."

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The following is a list of nutrients that some researchers (from the Institute of Food Technology) think of as especially beneficial to the brain. Other researchers may (or probably will) focus on other nutrients. I am posting it even though I generally dislike articles that talk about "superfoods" or an itemized list of foods that one should eat to the exclusion of others. Because, of course, focusing on some nutrients may leave out many just as important nutrients.

Also, medical thinking changes over time and what was once considered "unhealthy" may later be considered a wonderful food (remember when eggs, nuts, and coconuts were almost considered evil?). And vice versa (remember when margarine with partially hydrogeneated oils and trans-fats was considered healthier than butter?) And study after study says it is better to eat the foods, rather than take supplements. So keep in mind that the following nutrients are found in whole foods and in a varied diet. And when they mention a specific food such as blueberries, remember that ALL berries have benefits (though they vary), so eat a variety of berries. Same with nuts - eat a variety and not just walnuts. From Science Daily:

Eight nutrients to protect the aging brain

Brain health is the second most important component in maintaining a healthy lifestyle according to a 2014 AARP study. As people age they can experience a range of cognitive issues from decreased critical thinking to dementia and Alzheimer's disease. In the March issue of Food Technology published by the Institute of Food Technologists (IFT), contributing editor Linda Milo Ohr writes about eight nutrients that may help keep your brain in good shape.

1. Cocoa Flavanols: Cocoa flavanols have been linked to improved circulation and heart health, and preliminary research shows a possible connection to memory improvement as well. A study showed cocoa flavanols may improve the function of a specific part of the brain called the dentate gyrus, which is associated with age-related memory (Brickman, 2014). {NOTE: good sources are cocoa and dark chocolate}

2. Omega-3 Fatty Acids: Omega-3 fatty acids have long been shown to contribute to good heart health are now playing a role in cognitive health as well....Foods rich in omega-3s include salmon, flaxseed oil, and chia seeds.

3. Phosphatidylserine and Phosphatidic Acid: Two pilot studies showed that a combination of phosphatidylserine and phosphatidic acid can help benefit memory, mood, and cognitive function in the elderly (Lonza, 2014). {NOTE: good sources are fish and meat}

4. Walnuts: A diet supplemented with walnuts may have a beneficial effect in reducing the risk, delaying the onset, or slowing the progression of Alzheimer's disease in mice (Muthaiyah, 2014).

5. Citicoline: Citicoline is a natural substance found in the body's cells and helps in the development of brain tissue, which helps regulate memory and cognitive function, enhances communication between neurons, and protects neural structures from free radical damage.... {NOTE: Citocoline is synthesized in the body from choline, so see foods high in choline}

6. Choline: Choline, which is associated with liver health and women's health, also helps with the communication systems for cells within the brain and the rest of the body. Choline may also support the brain during aging and help prevent changes in brain chemistry that result in cognitive decline and failure. A major source of choline in the diet are eggs. { NOTE: Good sources of choline are eggs, meat, fish, beans, and cruciferous vegetables.}

7. Magnesium: Magnesium supplements are often recommended for those who experienced serious concussions. Magnesium-rich foods include avocado, soy beans, bananas and dark chocolate.

8. Blueberries: Blueberries are known to have antioxidant and anti-inflammatory activity because they boast a high concentration of anthocyanins, a flavonoid that enhances the health-promoting quality of foods. Moderate blueberry consumption could offer neurocognitive benefits such as increased neural signaling in the brain centers.

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People are living longer these days, but the desire is to age with mental faculties intact. Thus it is great to find research that looks at how one can increase the odds of not having cognitive problems or dementia in old age.

The research here suggests several things one can do, starting in middle-age, that may help in delaying thinking and memory problems: participating in arts, crafts, socializing, and computer activities. The lead researcher Dr. Roberts said: "The key point we want to get across is that you need to start these activities early"....if you start these activities earlier, perhaps in your 20s, "keep doing them throughout your life; don't stop as you get older."

Note that: Mild cognitive impairment (MCI) is an intermediate stage between the expected cognitive decline of normal aging and the more serious decline of dementia. It can involve problems with memory, language, thinking and judgment that are greater than normal age-related changes. From Medical Xpress:

Can arts, crafts and computer use preserve your memory?

People who participate in arts and craft activities and who socialize in middle and old age may delay the development in very old age of the thinking and memory problems that often lead to dementia, according to a new study published in the April 8, 2015, online issue of Neurology.

People age 85 and older make up the fastest growing age group in the United States and worldwide."As millions of older US adults are reaching the age where they may experience these memory and thinking problem called Mild Cognitive Impairment (MCI), it is important we look to find lifestyle changes that may stave off the condition," said study author Rosebud Roberts, MB, ChB, MS, of Mayo Clinic in Rochester, Minn. and a member of the American Academy of Neurology. "Our study supports the idea that engaging the mind may protect neurons, or the building blocks of the brain, from dying, stimulate growth of new neurons, or may help recruit new neurons to maintain cognitive activities in old age."

The study involved 256 people with an average age of 87 who were free of memory and thinking problems at the start of the study. The participants reported their participation in arts, such as painting, drawing and sculpting; crafts, like woodworking, pottery, ceramics, quilting, quilting and sewing; social activities, such as going to the theater, movies, concerts, socializing with friends, book clubs, Bible study and travel; and computer activities such as using the Internet, computer games, conducting web searches and online purchases.

After an average of four years, 121 people developed mild cognitive impairment. Participants who engaged in arts in both middle and old age were 73 percent less likely to develop MCI than those who did not report engaging in artistic activities. Those who crafted in middle and old age were 45 percent less likely to develop MCI and people who socialized in middle and old age were 55 percent less likely to develop MCI compared to those who did not engage in like activities. Computer use in later life was associated with a 53 percent reduced risk of MCI.

On the other hand, risk factors such as having the APOE gene, having high blood pressure in middle age, depression and risk factors related to blood vessels increased the risk of developing MCI.

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The following study raises the question  of how to lower BPA levels in all people, not just children with autism spectrum disorder.

The absolute quickest and easiest is to buy (whenever possible) loose foods (fresh fruits, vegetables, breads, etc) or foods in glass containers (and not plastic bottles, jars, or containers), store food in glass, porcelain, or stainless steel containers, and microwave in glass dishes (and not plastic containers).

In other words, think glass and not plastic. This is because BPA is in polycarbonate containers or packaging.

Lower your use of canned foods and avoid soda in cans. This is because cans have a lining that contains BPA or a BPA substitute (and research suggests it has the same effects as BPA). By the way, clear cling wrap made from polyethylene is considered safe to wrap and store food in.

From Medical Express: New study links BPA exposure to autism spectrum disorder

A newly published study is the first to report an association between bisphenol-A (BPA), a common plasticizer used in a variety of consumer food and beverage containers, with autism spectrum disorder (ASD) in children. The study, by researchers at Rowan University School of Osteopathic Medicine (RowanSOM) and Rutgers New Jersey Medical School (NJMS), shows that BPA is not metabolized well in children with ASD. The research appears online in Autism Research.

"It has been suspected for a lot of years that BPA is involved in autism, but there was no direct evidence," said T. Peter Stein, of RowanSOM and the study's lead author. "We've shown there is a link. The metabolism of BPA is different in some children with autism than it is in otherwise healthy children."

The research team – which included Margaret Schluter and Robert Steer, of RowanSOM who were responsible for laboratory analysis, and child neurologist Xue Ming, of NJMS who recruited and ascertained the study populations – examined urine specimens from 46 children with ASD and 52 healthy control children for both free BPA and total BPA concentrations.

Like many chemicals, BPA becomes water soluble when it is bound to glucose in the liver – a process called glucuronidation. Conversion to a glucuronide and then excretion of the glucuronide in the urine is a major pathway for removing toxins from the body.

The researchers also conducted a metabolomic analysis to screen for all the chemicals found in the children's urine. The metabolomics analyses showed the mean number of statistically significant correlations between metabolites detected and total BPA excreted to be approximately three times greater with the ASD group than the controls, and the number of statistical significant correlations with fraction of BPA bound was approximately 15 times higher in the children with ASD (p<0.001).

"Other studies involving rodent data have shown that BPA functions as an endocrine disruptor, but ours is the first to show this in humans and the first to associate it to autism," Stein said. "The observations show that for some children there was a relationship between intermediary metabolism, the ability to conjugate BPA and symptoms of autism."

Although the study involves a relatively small number of subjects, Stein said, "The key point is that the study seems to link BPA to autism and creates an open area for further research. One implication of our study is that there might be a benefit to reducing BPA exposure for pregnant women and for children with autism."

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Since people have abandoned using iodized salt and started using kosher salt or sea  salts, iodine deficiency has increased (especially during pregnancy when iodine needs are greater). The medical journal The Lancet noted in 2008: "According to World Health Organization, in 2007, nearly 2 billion individuals had insufficient iodine intake, a third being of school age. ... Thus iodine deficiency, as the single greatest preventable cause of mental retardation, is an important public-health problem." From Wikipedia : Iodine deficiency is the leading cause of preventable mental retardation, a result which occurs primarily when babies or small children are rendered hypothyroidic by a lack of the element. The addition of iodine to table salt has largely eliminated this problem in the wealthier nations. The article states that iodine deficiency typically lowers IQ by 10 to 15 points. So it's a big deal, a really big deal.  But don't overdo the iodine! Excess iodine also has serious problems.From Medscape:

New Recommendations Call for Iodine in All Prenatal Vitamins

Endocrinology groups are applauding a new recommendation from a dietary-supplement trade association that calls for iodine supplementation in all prenatal vitamins prescribed for pregnant and breastfeeding women.

In addition, the public health committee of the American Thyroid Association (ATA) recently published a statement reiterating the ATA recommendation that women take a daily multivitamin containing 150 μg of iodine during prepregnancy, pregnancy, and lactation. The statement also warns of the potential risks of excess iodine consumption and exposure, particularly through the use of unregulated kelp supplements.

The US Council for Responsible Medicine's new guidelines call for all dietary-supplement manufacturers and marketers to begin including at least 150 μg of iodine in all daily multivitamin/mineral supplements intended for pregnant and lactating women in the United States within the next 12 months.

In the past several years, removal of iodized salt from commercial products such as bread and milk, along with increased use of kosher salt and sea salt, which don't contain iodine, and the adoption of vegetarian and vegan diets have led to a reduction in dietary iodine consumption. "There never was a coherent US policy about iodization," Dr Stagnaro-Green noted.

Worldwide, about two billion people are iodine-deficient. While most of the US population has adequate iodine levels, data from the National Health and Nutrition Examination Survey suggest that more than half of pregnant women have urinary iodine concentrations below 150 mg/dL (Thyroid. 2011;21:419-427). 

Pregnant women actually need more iodine than other people because of increased thyroid-hormone production, renal losses, and fetal iodine requirements. Iodine deficiency during pregnancy can result in maternal and fetal goiter, cretinism, intellectual impairment, neonatal hypothyroidism, and increased pregnancy loss and mortality, Dr Stagnaro-Green and colleagues explained in a 2012 editorial (JAMA2012;308:2463-2464).

"So, women of childbearing age are the subpopulation of Americans with the lowest iodine levels yet have the greatest need during pregnancy and breastfeeding, for the neurodevelopment of the fetal and neonatal brain," he told Medscape Medical News. 

In 2009, a study found that only 51% of US prenatal multivitamin brands contained any iodine and, in a number of randomly selected brands, the actual dose of iodine contained in the supplements did not match values on the labeling.

However, the American College of Obstetricians and Gynecologists (ACOG) has not joined in these efforts. While the group does recommend the 150-μg dose for pregnant and lactating women, it does not currently endorse the prenatal-supplement recommendation, advising instead that women get their iodine through dietary sources.

In the ATA's public health committee statement, Angela M Leung, MD, from the University of California Los Angeles David Geffen School of Medicine, and colleagues, including Dr Stagnaro-Green, note that iodine is a micronutrient required for normal thyroid function. The US recommended daily allowances (RDA) for iodine intake are 150 μg in adults, 220 to 250 μg in pregnant women, and 250 to 290 μg in breastfeeding women. Dietary sources such as iodized salt, dairy products, some breads, and seafood usually contain enough to meet the RDA for most people who aren't pregnant or lactating.

However, there is an upper safety limit, with ingestion of more than 1100 μg/day not recommended due to the risk for thyroid dysfunction. In particular, infants, the elderly, pregnant and lactating women, and people with preexisting thyroid disease are at risk for adverse effects of excess iodine on the thyroid.

Many iodine, potassium iodide, and kelp supplements contain hundredfold greater amounts of iodine than the recommended upper limit, Leung and colleagues caution."Given the increasing popularity of iodine and kelp supplements, recommendations cautioning against excess iodine were indicated. The potential result of iodine-induced thyroid dysfunction, which may be particularly harmful during pregnancy and breastfeeding and in the elderly, may not be well-known," she told Medscape Medical News.

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Another study that links following the Mediterranean diet with a beneficial health effect - this time a lower risk of ischemic stroke. Unfortunately, it did not seem to lower the risk of hemorrhagic stroke.

The findings were presented at the American Stroke Association's annual meeting. From Medical Xpress:

Mediterranean diet may lower stroke risk, study finds

A Mediterranean diet may reduce your risk of one type of stroke, new research suggests. People who most closely followed the Mediterranean diet were less likely to suffer an ischemic stroke—caused by a blood clot—compared to people with the lowest adherence to the diet, the study found.

A Mediterranean diet includes plenty of fruits and vegetables, whole grains, legumes, nuts, fish, poultry and olive oil. There is limited consumption of red meat, sweets and saturated fats such as those in meat, butter and full-fat dairy products, according to the researchers.

Sherzai's team analyzed data from more than 104,000 teachers in California, averaging 52 years of age, who are taking part in a long-term study. The participants, 90 percent of who were white, were divided into five groups based on how well they followed a Mediterranean diet.

While closely following a Mediterranean diet was associated with a reduced risk of a stroke caused by a blood clot, the healthy eating plan had no effect on a person's odds for a bleeding (hemorrhagic) stroke, according to the study.

According to the researchers, prior research has shown that people who follow a Mediterranean diet have a lower risk of heart disease, mental decline and death, but there is little information about how the diet affects stroke risk.Wright noted that the study was especially rigorous, since the authors accounted for "other factors that would reduce stroke risks, such as exercise, total caloric intake,body mass index, smoking and menopausal/hormonal status."

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Another positive thing we can do for our brains - meditation.From Science Daily:

Forever young: Meditation might slow the age-related loss of gray matter in the brain

Since 1970, life expectancy around the world has risen dramatically, with people living more than 10 years longer. That's the good news.The bad news is that starting when people are in their mid-to-late-20s, the brain begins to wither -- its volume and weight begin to decrease. As this occurs, the brain can begin to lose some of its functional abilities.

Building on their earlier work that suggested people who meditate have less age-related atrophy in the brain's white matter, a new study by UCLA researchers found that meditation appeared to help preserve the brain's gray matter, the tissue that contains neurons.

The scientists looked specifically at the association between age and gray matter. They compared 50 people who had mediated for years and 50 who didn't. People in both groups showed a loss of gray matter as they aged. But the researchers found among those who meditated, the volume of gray matter did not decline as much as it did among those who didn't.

Dr. Florian Kurth, a co-author of the study and postdoctoral fellow at the UCLA Brain Mapping Center, said the researchers were surprised by the magnitude of the difference."We expected rather small and distinct effects located in some of the regions that had previously been associated with meditating," he said. "Instead, what we actually observed was a widespread effect of meditation that encompassed regions throughout the entire brain."

As baby boomers have aged and the elderly population has grown, the incidence of cognitive decline and dementia has increased substantially as the brain ages.

Each group in the study was made up of 28 men and 22 women ranging in age from 24 to 77. Those who meditated had been doing so for four to 46 years, with an average of 20 years.

The participants' brains were scanned using high-resolution magnetic resonance imaging. Although the researchers found a negative correlation between gray matter and age in both groups of people -- suggesting a loss of brain tissue with increasing age -- they also found that large parts of the gray matter in the brains of those who meditated seemed to be better preserved, Kurth said.

The researchers cautioned that they cannot draw a direct, causal connection between meditation and preserving gray matter in the brain. Too many other factors may come into play, including lifestyle choices, personality traits, and genetic brain differences.

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Experiencing positive emotions such as awe, wonder, and amazement are linked with lower levels of inflammation in the body . Another reason to seek out amazing, awe inspiring experiences - it's good for our mental and physical health. From Science Daily:

Add nature, art and religion to life's best anti-inflammatories

Taking in such spine-tingling wonders as the Grand Canyon, Sistine Chapel ceiling or Schubert's "Ave Maria" may give a boost to the body's defense system, according to new research from UC Berkeley. Researchers have linked positive emotions -- especially the awe we feel when touched by the beauty of nature, art and spirituality -- with lower levels of pro-inflammatory cytokines, which are proteins that signal the immune system to work harder.

"Our findings demonstrate that positive emotions are associated with the markers of good health," said Jennifer Stellar, a postdoctoral researcher at the University of Toronto and lead author of the study, which she conducted while at UC Berkeley.

While cytokines are necessary for herding cells to the body's battlegrounds to fight infection, disease and trauma, sustained high levels of cytokines are associated with poorer health and such disorders as type-2 diabetes, heart disease, arthritis and even Alzheimer's disease and clinical depression.

In two separate experiments, more than 200 young adults reported on a given day the extent to which they had experienced such positive emotions as amusement, awe, compassion, contentment, joy, love and pride. Samples of gum and cheek tissue, known as oral mucosal transudate, taken that same day showed that those who experienced more of these positive emotions, especially awe, wonder and amazement, had the lowest levels of the cytokine, Interleukin 6, a marker of inflammation.

In addition to autoimmune diseases, elevated cytokines have been tied to depression. One recent study found that depressed patients had higher levels of the pro-inflammatory cytokine known as TNF-alpha than their non-depressed counterparts. It is believed that by signaling the brain to produce inflammatory molecules, cytokines can block key hormones and neurotransmitters -- such as serotonin and dopamine -- that control moods, appetite, sleep and memory.

In answer to why awe would be a potent predictor of reduced pro-inflammatory cytokines, this latest study posits that "awe is associated with curiosity and a desire to explore, suggesting antithetical behavioral responses to those found during inflammation, where individuals typically withdraw from others in their environment," 

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Much has been written about boxing, concussions, and brain damage, but this is the first time I've read about mixed martial art fighters also having such problems. But it makes sense. From Medscape:

Fight Exposure Linked to Reduced Brain Volume

The more boxers and martial arts practitioners experience head trauma, the more likely they are to have lower brain volume, particularly caudate and thalamus volume, according to a new study. Lower brain volume in these fighters correlated with reduced processing speed, the study also found.

These results "suggest that greater exposure to head trauma is related to detectable brain structural and performance deficits in active fighters," the authors, led by Charles Bernick, MD, Lou Ruvo Center for Brain Health, Cleveland Clinic, Las Vegas, Nevada, conclude.

The analysis included 224 adults, aged 18 to 44 years, who were participants in the Professional Fighters Brain Health Study, a longitudinal cohort study of boxers and mixed martial arts (MMA) fighters. The participants included 93 boxers and 131 MMA fighters.The length of professional fighting in this group ranged from 0 to 24 years, with a mean of 4 years. The number of professional fights ranged from 0 to 101, with a mean of 10 fights.

The study also included a control group of 22 age- and education-matched participants with no history of head trauma who did not play a sport associated with head injuries from high school onward.Participants were assessed at baseline and then annually for 4 years. Researchers measured cognitive function with a computer-based battery consisting of tests of  verbal memory, processing speed, and other functions. They used MRI to assess brain volumes.

The study found that increasing exposure to head trauma, as measured by the number of professional fights or years of professional fighting, was generally associated with lower brain structural volumes, particularly subcortical structures. The most consistent relationship between exposure variables and brain volume was seen in the thalamus and caudate. 

The thalamus acts as a "gateway" to the cortex and when affected can influence many neurologic functions, said the authors. It and the caudate are vulnerable to volumetric loss through several mechanisms. Rotational movement of the head brought on by punches in boxing or MMA can result in diffuse axonal injury in white matter tracts, they note.

For the most part, brain structure volumes were lower for boxers than MMA fighters or controls. This could be due to several factors, the authors write. "Perhaps the most obvious explanation is that boxers get hit in the head more. In addition to trying to concuss (ie, knock out) their opponent, MMA fighters can utilise other combat skills such as wrestling and jiu jitsu to win their match by submission without causing a concussion."

The study also found that processing speed was correlated with reduced volume in several cortical and subcortical structures. Reduction in processing speed, said the authors, is consistent with repeated concussions and is considered a clinical component of chronic traumatic encephalopathy.