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Published on Leave a comment on Vitamin D and Folic Acid Levels During Pregnancy

 Two interesting studies about vitamins during pregnancy and possible effects on the child. One found that low levels of vitamin D3 is linked to behavioral issues and ADHD symptoms in preschool aged children, while the other raises the possibility of very high levels of folic acid during pregnancy linked to autism in the child. More studies are needed.

From Medscape:  Maternal Vitamin D Deficiency and Behavioral Issues in Offspring

Maternal vitamin D deficiency in early pregnancy is associated with an increased risk of behavioral issues and attention-deficit/hyperactivity disorder (ADHD)–like symptoms in preschool children, according to new data from a birth cohort study in Greece. But no association was found between maternal vitamin D deficiency and cognitive scores in the children at age 4, reported Vasiliki Daraki, MD, an endocrinologist from the University of Crete, Heraklion, Greece, who led the analysis, which was  a poster presented at the European Congress of Endocrinology 2016.

The analysis showed that maternal vitamin D levels lower than 50 nmol/L during the first trimester of pregnancy were associated with increased behavioral problems and ADHD-like symptoms among the offspring...."The lower the mother's vitamin D levels, the higher the child's hyperactivity and inattention," reported Dr Daraki.

"I think the role of vitamin D in the developing brain is in neuronal differentiation and axon development, and these are more important for behavioral problems than for cognition," Dr Daraki added.....In the future, she and her colleagues intend to measure the cognitive function and behavioral status at the age of 7 years and determine whether the results still hold at the later age.

From Medical Xpress:  A study asks: Too much folic acid a cause of autism?

For decades, pregnant women and women who may become pregnant have been advised to take folic acid to help prevent certain birth defects. But a new study suggests it may be possible to get too much of a good thing—very high levels of the vitamin in mothers' blood at the time of childbirth was linked to higher risk of their children developing autism years later. (Other research points to an opposite relationship between folic acid and autism, showing that adequate amounts of the vitamin at the time of conception can significantly reduce the risk.) 

Folate is a vitamin found in foods that is important in cell growth and development of the nervous system. A synthetic version, folic acid, is used in supplements and is used to fortify flour and cereals. Decades ago, researchers found certain levels of folic acid could prevent major birth defects of the baby's brain and spine. In the early 1990s, U.S. health officials began recommending that all women who might become pregnant should take 400 micrograms of folic acid daily. And in the late 1990s, federal regulations began mandating that folic acid be added to flour, bread and other grain products.

The new researchers followed 1,391 children who were born at Boston University Medical Center in 1998 through 2013. About 100 of them were later diagnosed with an autism spectrum disorder. The researchers went back and looked at levels of folate and vitamin B12 in the blood of the children's mothers at the time of childbirth. They found that 16 of them had very high levels of folate, and 15 had extremely high levels of vitamin B12. If both levels are extremely high, there is more than a 17-fold greater risk that a child will develop autism, the researchers said. 

Most of the moms in the study said they took multivitamins—which would include folic acid and vitamin B12—throughout their pregnancy. But the researchers say they don't know why some women had such high levels in their blood. It may be related to taking too many supplements and eating too many fortified foods. Or there could be a genetic reason that caused some women to absorb more folate than others. Or there could be a combination, they said.

Published on Leave a comment on BPA Levels in Children and ADHD?

A recent study found that school age children with higher levels of BPA in their bodies were more likely to have an ADHD (Attention Deficit Hyperactivity Disorder)  diagnosis. BPA or Bisphenol A is everywhere (in plastics, linings of cans, etc), found in varying levels in almost everyone, but at least it is eliminated fairly rapidly from the body. So trying to avoid BPA (e.g., buying and storing food in glass containers rather than cans or plastic containers) can quickly lower levels in the body. From Environmental Health News:

Hyperactivity in children linked to plastic additive, BPA

Children in the U.S. with higher levels of BPA in their bodies were more likely to have Attention-Deficit/Hyperactivity Disorder (ADHD), according to a study. The study of 460 children across the U.S. aged 8 to 15 years old found that 11 percent of those with BPA levels higher than the median level had ADHD. In contrast, 3 percent of those children with BPA levels below the median had ADHD. The research, published online last week in the Environment Research journal, adds to evidence that children’s BPA exposure may alter brain development and lead to behavior problems such as reduced attention and hyperactivity. 

The association was stronger for boys than girls, which reflects broader ADHD rates. Nationally about 10 percent of children between 5 and 17 have had an ADHD diagnoses, with boys having a much higher rate at 14 percent. By comparison about 6 percent of girls have the disorder, according to the U.S. Centers for Disease Control and Prevention.....BPA mimics estrogen hormones.The sexes use hormones differently to influence brain function.

BPA—used to make plastic hard and shatterproof and to extend the shelf life of canned food—can leach out of can linings and into the food. Studies show that just about everyone has traces of the chemical in their body—for instance, 97 percent of the children in this study had BPA in their urine. The additive has been linked to multiple health impacts in exposed babies and children—including obesity, asthma, low birth weights and genital defects.

A 2014 study on prenatal exposure to BPA found higher levels meant more behavior problems for school-age boys. Evans, lead author of that study, said prenatal exposure to chemicals is a “window of high susceptibility,” but so are the childhood years. The brain keeps developing into the 20s. Research specifically looking at ADHD and BPA exposure has been mixed, with some finding a link and some not. Most of the previous studies, however, have been on children younger than 8 years old, and ADHD and its symptoms are often realized later than that.

Animal studies show that BPA may alter the body’s dopamine—a chemical messenger that helps people think and stay alert and focused. “Dopamine systems are modulated by estrogen and BPA is a synthetic estrogen,” Froehlich said. There are also suggestions that BPA can interact with thyroid hormones—“critical in normal brain development,” Evans said.

Published on Leave a comment on Exercise Now to Protect Your Brain Decades From Now

Get out there and start getting active NOW - the earlier you start in life, the better for your brain decades later. All physical activity or exercise is good, including regular walks. From Medical Xpress:

Regular exercise protects against cognitive decline in later years

Regular exercise in middle age is the best lifestyle change a person can make to prevent cognitive decline in the later years, a landmark 20-year study has found.

University of Melbourne researchers followed 387 Australian women from the Women's Healthy Ageing Project for two decades. The women were aged 45 to 55-years-old when the study began in 1992. The research team made note of their lifestyle factors, including exercise and diet, education, marital and employment status, number of children, mood, physical activity and smoking....They were also asked to learn a list of 10 unrelated words and attempt to recall them half an hour later, known as an Episodic Verbal Memory test.

When measuring the amount of memory loss over 20 years, frequent physical activity, normal blood pressure and high good cholesterol were all strongly associated with better recall of the words. Study author Associate Professor Cassandra Szoeke, who leads the Women's Healthy Ageing Project, said once dementia occurs, it is irreversible. "In our study more weekly exercise was associated with better memory." 

"We now know that brain changes associated with dementia take 20 to 30 years to develop," Associate Professor Szoeke said. "The evolution of cognitive decline is slow and steady, so we needed to study people over a long time period. We used a verbal memory test because that's one of the first things to decline when you develop Alzheimer's Disease."
Regular exercise of any type, from walking the dog to mountain climbing, emerged as the number one protective factor against memory loss. Asoc Prof Szoeke said that the best effects came from cumulative exercise, that is, how much you do and how often over the course of your life.  (Original study)

Published on Leave a comment on Vitamin B12 and the Aging Brain

Another piece of the puzzle on how the brain ages. Vitamin B12 is important for brain health, and higher levels are associated with slower rates of brain changes associated with aging. And the opposite is true with homocysteine levels - increased levels are associated with faster rates of brain changes that are associated with aging (such as higher rates of total brain tissue volume loss). Keep in mind that these effects were modest, but this also raises the question of whether long-term B12 supplementation would benefit everyone or only those with a deficiency? From Medscape:

Vitamin B12 May Slow Brain Aging

Individuals with increased levels of circulating homocysteine have faster rates of brain changes associated with aging than other people, whereas higher levels of vitamin B12 are associated with slower rates of brain aging, new research suggests.

Babak Hooshmand, MD, PhD, Center for Alzheimer Research–Aging Research Center, Karolinska Institutet, Stockholm, Sweden, and colleagues found that total brain volume losses were lower in individuals with higher baseline vitamin B12 levels, whereas the opposite was true of those with increased homocysteine levels.

"Vitamin B12 and tHcy [total homocysteine] might be independent predictors of markers of brain aging in elderly individuals without dementia," the investigators write. They add, "[I]f the association is causal, supplementation with B vitamins may be effective for prevention of brain damage due to increased levels of total homocysteine. Adequately timed and powered randomized clinical trials are needed to determine efficient treatment guidelines." The research was published online April 27 in JAMA Psychiatry.

The researchers examined data on 501 participants aged 60 years and older from the Swedish National Study on Aging and Care, in Kungsholmen. All participants were free of dementia at baseline. Of these, 299 underwent repeated structural brain MRI between 2001 and 2009....Venous blood samples were collected at baseline, from which circulating levels of vitamin B12, red blood cell folate, and sulfur amino acids were determined. These were correlated with changes in brain tissue volumes and total white matter hyperintensity (WMH) over 6 years.

He also pointed to the single-center, randomized VITACOG study, in which 271 individuals older than 70 years who had mild cognitive impairment received supplementation with high-dose folic acid and vitamins B6 and B12. "They lost less brain compared to people who had normal homocysteine and normal vitamin levels, meaning that those with high levels of homocysteine or with clinical or biochemical vitamin deficiency can benefit from supplementation," said Dr Hooshmand.

Published on Leave a comment on Increase Fruit Intake During Pregnancy and Boost Baby’s Cognitive Development?

Increasing fruit and fruit juice consumption during pregnancy leads to better cognitive development in babies? New research found that six or seven servings of fruit or fruit juice a day prenatally was associated with 6 or 7 points higher IQ at one year of age. Interestingly, fruit flies show a similar effect. But postnatal (after birth) fruit intake did not enhance cognitive outcomes in human babies or Drosophila fruit flies. But now, will these results in the babies hold up over time?

The US Department of Agriculture (USDA) and US Department of Health and Human Services recommend 2 cups (3–4 servings) of fruit per day for active women. One cup of fruit (2 servings) consists of either 1 cup of raw or cooked fruit, 1 cup (8 oz) of 100% fruit juice, or a small whole fruit. Note that the results of the study support an increased consumption of fruit to 6–7 servings or 3 cups per day for pregnant women.From Science Daily:

Prenatal fruit consumption boosts babies' cognitive development

The benefits of eating fruit can begin as early as in the womb....The study, published in the journal EbioMedicine, found that mothers who consumed more fruit during pregnancy gave birth to children who performed better on developmental testing at one year of age. Piush Mandhane, senior author of the paper and associate professor of pediatrics at the University of Alberta's Faculty of Medicine & Dentistry, made the discovery using data from the Canadian Healthy Infant Longitudinal Development (CHILD) Study--a nationwide birth cohort study involving over 3,500 Canadian infants and their families.

"We wanted to know if we could identify what factors affect cognitive development," Mandhane explains. "We found that one of the biggest predictors of cognitive development was how much fruit moms consumed during pregnancy. The more fruit moms had, the higher their child's cognitive development."

The study examined data from 688 Edmonton children, and controlled for factors that would normally affect a child's learning and development such as family income, paternal and maternal education, and the gestational age of the child. Using a traditional IQ scale as a model, the average IQ is 100 and the standard deviation is 15; two thirds of the population will fall between 85 and 115. Mandhane's study showed that if pregnant mothers ate six or seven servings of fruit or fruit juice a day, on average their infants placed six or seven points higher on the scale at one year of age.

To further build on the research, Mandhane teamed with Francois Bolduc, an associate professor in the Faculty of Medicine & Dentistry's Division of Pediatric Neurology, who researches the genetic basis of cognition in humans and fruit flies....."Flies are very different from humans but, surprisingly, they have 85 per cent of the genes involved in human brain function, making them a great model to study the genetics of memory," says Bolduc....In a subsequent series of experiments, he showed that flies born after being fed increased prenatal fruit juice had significantly better memory ability, similar to the results shown by Mandhane with one-year-old infants. He believes it suggests that brain function affected by fruit and the mechanisms involved have been maintained through evolution, and conserved across species.

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Published on 1 Comment on Why Are Very Young Children Given ADHD Meds?

This is so sad. Preschoolers should not be labeled as ADHD and drugged, but instead behavioral methods to deal with the child's behaviors should be used. They absolutely work. But...it takes effort and commitment on the part of the parents.

Just filling a prescription is soooo much easier. But all medicines have side-effects (and the side-effects are serious). These are young developing children (with developing brains) that are put on strong medicines for years. Currently we do not have a good understanding of long-term effects of these ADHD drugs when given at such a young age and continued for years.

The Centers for Disease Control and Prevention is disturbed by the finding that 3 out of 4 very young children with an ADHD diagnosis are given medications and says behavior therapy is the recommended first-line treatment. Specifically: "Behavior therapy is an effective treatment that improves ADHD symptoms without the side effects of medicine."

And by the way, basically all children 2 and 3 years old (and older) exhibit behaviors that some can label as ADHD. No matter how one looks at it, the diagnosis is used too much in young children, behavioral methods to deal with problem behaviors are underused, and medicines are overused.

From Medical Xpress: CDC: Preschoolers with ADHD often given drugs before therapy

Too many preschoolers with ADHD still are being put on drugs right away, before behavior therapy is tried, health officials say. The Centers for Disease Control and Prevention reported Tuesday that three in four young kids diagnosed with attention deficit hyperactivity disorder are put on medicines. New CDC data shows that's continued, even after research found behavior therapy is as effective and doesn't give children stomach aches, sleep problems or other drug side effects. 

Why? Health insurance coverage for behavior therapy may vary from state to state and company to company. And in some areas, therapists are in short supply, some experts said. On Tuesday, CDC officials doubled down on its previous recommendations, calling on doctors and families to try behavior therapy first.

ADHD makes it hard for kids to pay attention and control impulsive behavior. More than 6 million U.S. children have been diagnosed with it. "By the time a parent comes to meet with me, they are tired and worried," Dr. Georgina Peacock, a CDC developmental pediatrician who works with ADHD families. "They are concerned their child might jump down a flight of stairs, that the child could get lost in a grocery store, or that the child could be kicked out of preschool."

There's no blood test for ADHD. Diagnosis is a matter of expert opinion. Studies have shown medications like ritalin help older children with ADHD. That success has fed a trend to treat younger kids the same way, but there's been less study of how effective and safe the drugs are for preschoolers. In behavior therapy, a therapist trains parents—commonly over eight or more sessions—how to guide a child's behavior through praise, communication, routine and consistent discipline. However, it can take longer and demand more of parents.

In its new analysis, the CDC looked at insurance claims data for children ages 2 to 5. ....The CDC found 75 percent of the children were on medicine. That was true both of Medicaid-covered children in low-income families, and kids covered by private insurance. In contrast, only around half of children had received psychological services that might include behavior therapy training, the CDC found.

Published on Leave a comment on One Season of High School Football Results In Brain Changes

Study after study finds negative effects on the brain from playing football - here it is one season of high school football resulting in measurable brain changes. None of these players had a concussion during the season, and so the negative effects were from subconcussive head impacts or hits. Interestingly, those special helmets they wore to measure impacts showed no relationship with what the brain scans showed - so the helmets were basically useless in measuring subconcussive impacts. From Science Daily:

Head impacts from single season of high school football produce measurable change in brain cells

Repeated impacts to the heads of high school football players cause measurable changes in their brains, even when no concussion occurs, according to new research. Researchers gathered data from high school varsity players who donned specially outfitted helmets that recorded data on each head impact during practice and regular games. They then used experimental techniques to measure changes in cellular microstructure in the brains of the players before, during, and after the season.

"Our findings add to a growing body of literature demonstrating that a single season of contact sports can result in brain changes regardless of clinical findings or concussion diagnosis," said senior author Dr. Joseph Maldjian, Chief of the Neuroradiology Division and Director of the Advanced Neuroscience Imaging Research Lab, part of the Peter O'Donnell Jr. Brain Institute at UT Southwestern.

In the study, appearing in the Journal of Neurotrauma, a team of investigators at UT Southwestern, Wake Forest University Medical Center, and Children's National Medical Center evaluated about two dozen players over the course of a single football season.....During the pre-season each player had an MRI scan and participated in cognitive testing, which included memory and reaction time tests. During the season they wore sensors in their helmets that detected each impact they received. Post-season, each player had another MRI scan and another round of cognitive tests. 

Researchers then used diffusional kurtosis imaging (DKI), which measures water diffusion in biological cells, to identify changes in neural tissues. ....DKI also allowed the researchers to measure white matter abnormalities. White matter consists of fibers that connect brain cells and can speed or slow signaling between nerve cells. In order for the brain to reorganize connections, white matter must be intact and the degree of white matter damage may be one factor that limits the ability of the brain to reorganize connections following TBI.

Football has the highest concussion rate of any competitive contact sport, and there is growing concern -- reflected in the recent decrease in participation in the Pop Warner youth football program -- among parents, coaches, and physicians of youth athletes about the effects of subconcussive head impacts, those not directly resulting in a concussion diagnosis, researchers noted. Previous research has focused primarily on college football players, but recent studies have shown impact distributions for youth and high school players to be similar to those seen at the college level, with differences primarily in the highest impact magnitudes and total number of impacts, the researchers noted.

Published on Leave a comment on Chocolate, Cognitive Function, and Athletic Performance

Image result for dark chocolate Two new studies finding benefits from chocolate consumption: dark chocolate boosting athletic performance (in cycling), and long-term chocolate consumption (several times a week for many years) linked to better cognitive function. From Medical Xpress:

Eating chocolate improves cognitive function, study finds

People who ate chocolate at least once a week performed better on multiple cognitive tasks, compared to those who ate chocolate less frequently, according to a new study by researchers at the University of Maine, University of South Australia and Luxembourg Institute of Health that has garnered international attention. 

With age, education, gender, age and race controlled, cognitive tasks were related to following domains, each measured by multiple tests: Visual-Spatial Memory and Organization, Working Memory, Abstract Verbal Reasoning, Scanning and Tracking, and overall cognitive functioning. The 968 participants ages 23–98 in the study came from the Maine-Syracuse Longitudinal Study, directed by Elias, which has tracked more than 1,000 people over 35 years.

The researchers hypothesized that regular intake of cocoa flavanols may be one of several mechanism explaining the cognitive benefits of chocolate. In addition, compared to those who never or rarely ate chocolate, those who ate chocolate weekly had higher total and LDL cholesterol, but lower glucose levels. Hypertension and Type 2 diabetes also were lower in regular chocolate consumers than in nonconsumers. 

From Medical Xpress: Eating dark chocolate as a daily snack could help boost athletic performance, study suggests

Dark chocolate has already been hailed for its positive effects on cardiovascular health – and now a study undertaken at London's Kingston University has found the tasty treat could help give sports enthusiasts an extra edge in their fitness training. A team led by postgraduate research student Rishikesh Kankesh Patel discovered that dark chocolate provides similar benefits to beetroot juice, now taken regularly by elite athletes after studies showed it can improve performance. "Beetroot juice is rich in nitrates, which are converted to nitric oxide in the body. This dilates blood vessels and reduces oxygen consumption – allowing athletes to go further for longer," Mr Patel explained.

The Kingston University team wanted to find out whether dark chocolate could provide a similar boost, as it contains a substance called epicatechin – a type of flavanol found in the cacao bean, that also increases nitric oxide production in the body.

To test the theory, Mr Patel carried out a study with a group of nine amateur cyclists.....After undergoing initial fitness tests to establish a baseline for comparison, the participants were then split into two groups. The first group was asked to replace one of its normal daily snacks with 40 g of a dark chocolate known to be rich in flavanols for a fortnight, while the other participants substituted 40 g of white chocolate for one of their daily snacks as a control.

The effects of the athletes' daily chocolate consumption were then measured in a series of cycling exercise tests in the sports performance laboratory at the University's Penrhyn Road campus....The study, which has now been published in the Journal of the International Society of Sports Nutrition, found that after eating dark chocolate, the riders used less oxygen when cycling at a moderate pace and also covered more distance in a two-minute flat-out time trial.

Published on Leave a comment on Some Popular Medicines Have Negative Brain Effects

Another study showing big problems with anticholinergics, which are in many popular medicines - both non-prescription and prescription (e.g., Chlor-Trimeton, Benadryl, Tavist, Dimetapp). An earlier study with older adults found a dose-response link with dementia, but the current study explored this issue further. They followed 2 groups of  "cognitively normal older adults" in their early 70s for several years: those who took anticholinergic medicines and those who did not take anticholinergic medicines. They found that those who took anticholinergic medicines had reduced brain volume (brain shrinking) and cognitive decline (when compared to those who did not take anticholinergic medicines). The researchers summarized their findings as the "use of anticholinergic medication was associated with increased brain atrophy and dysfunction and clinical decline". This finding was greatest for those taking drugs with the most anticholinergic activity.

See a list of anticholinergic medicines  from the Aging Brain Program of the Indiana University Center for Aging Research. Definitely try to avoid medicines with a score of 2 (medium effect) or 3 (high effect), but I would even be cautious about score 1 (low effect) medicines - use all medicines only as long as absolutely needed. My one very important question is: If these effects are found in older adults, what do anticholinergics do to younger brains, especially the developing brains of children? From Medical Xpress:

Brain scans link physical changes to cognitive risks of widely used class of drugs

Older adults might want to avoid a using class of drugs commonly used in over-the-counter products such as nighttime cold medicines due to their links to cognitive impairment, a research team led by scientists at Indiana University School of Medicine has recommended. Using brain imaging techniques, the researchers found lower metabolism and reduced brain sizes among study participants taking the drugs known to have an anticholinergic effect, meaning they block acetylcholine, a nervous system neurotransmitter.

Previous research found a link between between the anticholinergic drugs and cognitive impairment and increased risk of dementia.....Drugs with anticholinergic effects are sold over the counter and by prescription as sleep aids and for many chronic diseases including hypertension, cardiovascular disease, and chronic obstructive pulmonary disease. A list of anticholinergic drugs and their potential impact is at http://www.agingbraincare.org/uploads/products/ACB_scale_-_legal_size.pdf.

Scientists have linked anticholinergic drugs and cognitive problems among older adults for at least 10 years. A 2013 study by scientists at the IU Center for Aging Research and the Regenstrief Institute found that drugs with a strong anticholinergic effect cause cognitive problems when taken continuously for as few as 60 days. Drugs with a weaker effect could cause impairment within 90 days.

The current research project involved 451 participants, 60 of whom were taking at least one medication with medium or high anticholinergic activity. The participants were drawn from a national Alzheimer's research project....and the Indiana Memory and Aging Study. To identify possible physical and physiological changes that could be associated with the reported effects, researchers assessed the results of memory and other cognitive tests, positron emission tests (PET) measuring brain metabolism, and magnetic resonance imaging (MRI) scans for brain structure.

The cognitive tests revealed that patients taking anticholinergic drugs performed worse than older adults not taking the drugs on short-term memory and some tests of executive function, which cover a range of activities such as verbal reasoning, planning, and problem solving. Anticholinergic drug users also showed lower levels of glucose metabolism—a biomarker for brain activity—in both the overall brain and in the hippocampus, a region of the brain associated with memory and which has been identified as affected early by Alzheimer's disease. The researchers also found significant links between brain structure revealed by the MRI scans and anticholinergic drug use, with the participants using anticholinergic drugs having reduced brain volume and larger ventricles, the cavities inside the brain.

Published on Leave a comment on Subconcussions and Brain Changes in College Football Players

In the last few years some people have raised the issue of whether subconcussions in chidren, teenagers, and adults playing football also leads to brain changes similar to concussions. Subconcussions are head impacts that aren't as strong as concussions, but they routinely happen to players in football games and practice. Research says YES - worrying brain changes are occurring from subconcussions, but long-term effects from them are currently unknown. Earlier research found that the brains of high school football players (who had only received head impacts during the season) don't fully heal during the off-season when football is not played. (More related posts on subconcussions: high school players, football before age 12, teen football players, soccer players). The research discussed below is ongoing research. From Medical Xpress:

Subconcussions cause changes to brain, study of college football players shows

The average college football player receives about 1,000 head impacts each season. Some of these hits result in concussions – traumatic head injury that results in short-term, and possibly even long-term, damage to brain function. But what are the effects of the hundreds of routine head impacts, called subconcussions, that occur during a four-month season of practice sessions and games?

A University of Virginia neuroscience Ph.D. candidate is trying to find out. Using functional magnetic resonance imaging – fMRI – Bryson Reynolds studied the brain activity and connectivity of a group of healthy college football players, before and after a competitive season, and compared the data to brain-activity scans of healthy male college soccer and lacrosse players, and to a control group of college male non-athletes.

He found that the football players experienced a disruption in "local functional connectivity" – the way different areas of the brain communicate with each other – while soccer and lacrosse players' brain activity did not noticeably change after a competitive season. The result for the soccer and lacrosse players was comparable to the control group, which also displayed no brain activity changes during a four-month period. "This is an important discovery regarding the football players because a similar disruption of local functional connectivity has also been found in athletes diagnosed with a concussion," Reynolds said.

"We have no ideas how these subconcussions might be affecting players' brains, but we are seeing concussion-like changes to the brain, at least in the short term," Reynolds said. "This does not necessarily mean that something bad is happening to the brain, but clearly some changes are occurring over the course of a season."

Neurologists know that concussions cause headaches, dizziness and sometimes loss of consciousness, and may also increase the risk for developing serious long-term neurodegenerative disorders, such as Alzheimer's disease, amyotrophic lateral sclerosis and chronic traumatic encephalopathy.

In other words, repeated head impacts over the course of a season, or perhaps a career, may be affecting the brain in ways not yet understood, but possibly similar to actual concussions. Reynolds' study did not include players who suffered concussions, and the subconcussions he observed were not causing perceptible problems or symptoms for the players. But the disruptions in brain activity recorded in the fMRI scans may indicate subtle changes that could be part of a larger picture.