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Category: brain

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This research finding of lower IQ in children with higher exposure to 2 common phthalates during pregnancy is very troubling. Especially since avoiding all phthalates in the USA is currently impossible. But one can lower levels in the body by reading all ingredients and trying to avoid certain products (e.g. dryer sheets, vinyl shower curtains, personal care products with phthalates, scented products). And don't microwave food in plastic containers. From Science Daily:

Prenatal exposure to common household chemicals linked with substantial drop in child IQ

Children exposed during pregnancy to elevated levels of two common chemicals found in the home -- di-n-butyl phthalate and di-isobutyl phthalate -- had an IQ score, on average, more than six points lower than children exposed at lower levels, according to researchers.

DnBP and DiBP are found in a wide variety of consumer products, from dryer sheets to vinyl fabrics to personal care products like lipstick, hairspray, and nail polish, even some soaps. Since 2009, several phthalates have been banned from children's toys and other childcare articles in the United States. 

Researchers followed 328 New York City women and their children from low-income communities. They assessed the women's exposure to four phthalates--DnBP, DiBP, di-2-ethylhexyl phthalate, and diethyl phthalate--in the third trimester of pregnancy by measuring levels of the chemicals' metabolites in urine. Children were given IQ tests at age 7.

Children of mothers exposed during pregnancy to the highest 25 percent of concentrations of DnBP and DiBP had IQs 6.6 and 7.6 points lower, respectively, than children of mothers exposed to the lowest 25 percent of concentrations after controlling for factors like maternal IQ, maternal education, and quality of the home environment that are known to influence child IQ scores. The association was also seen for specific aspects of IQ, such as perceptual reasoning, working memory, and processing speed. The researchers found no associations between the other two phthalates and child IQ. The range of phthalate metabolite exposures measured in the mothers was not unusual: it was within what the Centers for Disease Control and Prevention observed in a national sample.

"A six- or seven-point decline in IQ may have substantial consequences for academic achievement and occupational potential.""While there has been some regulation to ban phthalates from toys of young children," adds Dr. Factor-Litvak, "there is no legislation governing exposure during pregnancy, which is likely the most sensitive period for brain development. Indeed, phthalates are not required to be on product labeling."

While avoiding all phthalates in the United States is for now impossible, the researchers recommend that pregnant women take steps to limit exposure by not microwaving food in plastics, avoiding scented products as much as possible, including air fresheners, and dryer sheets, and not using recyclable plastics labeled as 3, 6, or 7.

The findings build on earlier, similar observations by the researchers of associations between prenatal exposure to DnBP and DiBP and children's cognitive and motor development and behavior at age 3. This September, they reported a link between prenatal exposure to phthalates and risk for childhood asthma. It's not known how phthalates affect child health. However, numerous studies show that they disrupt the actions of hormones, including testosterone and thyroid hormone. Inflammation and oxidative stress may also play a role.

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More discussion of the benefits of vitamin D. From Science Daily:

Vitamin D deficiency, depression linked in international study

Vitamin D deficiency is not just harmful to physical health -- it also might impact mental health, according to a team of researchers that has found a link between seasonal affective disorder, or SAD, and a lack of sunlight. "Rather than being one of many factors, vitamin D could have a regulative role in the development of SAD," said Alan Stewart of the University of Georgia College of Education.

Stewart and Michael Kimlin from QUT's School of Public Health and Social Work conducted a review of more than 100 leading articles and found a relationship between vitamin D and seasonal depression."Seasonal affective disorder is believed to affect up to 10 percent of the population, depending upon geographical location, and is a type of depression related to changes in season," said Stewart, an associate professor in the department of counseling and human development services.

"We believe there are several reasons for this, including that vitamin D levels fluctuate in the body seasonally, in direct relation to seasonally available sunlight," he said. "For example, studies show there is a lag of about eight weeks between the peak in intensity of ultraviolet radiation and the onset of SAD, and this correlates with the time it takes for UV radiation to be processed by the body into vitamin D.

Vitamin D is also involved in the synthesis of serotonin and dopamine within the brain, both chemicals linked to depression, according to the researchers. "Evidence exists that low levels of dopamine and serotonin are linked to depression, therefore it is logical that there may be a relationship between low levels of vitamin D and depressive symptoms," said Kimlin, a Cancer Council Queensland Professor of Cancer Prevention Reseach. "Studies have also found depressed patients commonly had lower levels of vitamin D."

Vitamin D levels varied according to the pigmentation of the skin. People with dark skin often record lower levels of vitamin D, according to the researchers.

Kimlin, who heads QUT's National Health and Medical Research Council Centre for Research Excellence in Sun and Health, said adequate levels of vitamin D were essential in maintaining bone health, with deficiency causing osteomalacia in adults and rickets in children. Vitamin D levels of more than 50 nanomoles per liter are recommended by the U.S. Institute of Medicine...."A few minutes of sunlight exposure each day should be enough for most people to maintain an adequate vitamin D status."

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Makes sense. From Science Daily:

High school football players show brain changes after one season, even in absence of concussions

Some high school football players exhibit measurable brain changes after a single season of play even in the absence of concussion, according to a new study.

Dr. Whitlow and colleagues set out to determine if head impacts acquired over a season of high school football produce white matter changes in the brain in the absence of clinically diagnosed concussion.The researchers studied 24 high school football players between the ages of 16 and 18. For all games and practices, players were monitored with Head Impact Telemetry System (HITs) helmet-mounted accelerometers, which are used in youth and collegiate football to assess the frequency and severity of helmet impacts.

Risk-weighted cumulative exposure was computed from the HITs data, representing the risk of concussion over the course of the season. This data, along with total impacts, were used to categorize the players into one of two groups: heavy hitters or light hitters. There were nine heavy hitters and 15 light hitters. None of the players experienced concussion during the season.

All players underwent pre- and post-season evaluation with diffusion tensor imaging (DTI) of the brain. DTI is an advanced MRI technique, which identifies microstructural changes in the brain's white matter.

The brain's white matter is composed of millions of nerve fibers called axons that act like communication cables connecting various regions of the brain. Diffusion tensor imaging produces a measurement, called fractional anisotropy (FA), of the movement of water molecules along axons. In healthy white matter, the direction of water movement is fairly uniform and measures high in fractional anisotropy. When water movement is more random, fractional anisotropy values decrease, suggesting microstructural abnormalities.

The results showed that both groups demonstrated global increases of FA over time, likely reflecting effects of brain development. However, the heavy-hitter group showed statistically significant areas of decreased FA post-season in specific areas of the brain, including the splenium of the corpus callosum and deep white matter tracts.

"Our study found that players experiencing greater levels of head impacts have more FA loss compared to players with lower impact exposure," Dr. Whitlow said. "Similar brain MRI changes have been previously associated with mild traumatic brain injury. However, it is unclear whether or not these effects will be associated with any negative long-term consequences."

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Please note that the study was of people living in the Baltimore, Maryland area - so it is unknown if this would hold true for people living elsewhere. From Medical Xpress;

Virus may affect mental abilities, study reports

People with an algae virus in their throats had more difficulty completing a mental exercise than healthy people, and more research is needed to understand why, US scientists say. A study in the Proceedings of the National Academy of Sciences showed that the virus was present in about half of 92 human subjects studied, and those who had it performed worse on certain basic tasks.

The virus, known as Acanthocystis turfacea Chlorella virus 1, or ATCV-1, also appeared to limit the cognitive abilities of mice.The mice had a harder time navigating a maze and noticing new objects in their surroundings after they were infected.

It remains unclear if the virus was truly driving the drop in mental functioning. Researchers have not yet shown the cause and effect between the virus and the intelligence results."At this point we do not think that this virus should be considered as a threat to individual or public health," said lead researcher Robert Yolken, a virologist at Johns Hopkins University in Baltimore, Maryland. The virus was found by accident while scientists were analyzing microbes in the throats of healthy humans for a different study.

Experts have been studying viruses similar to ATCV-1 for 35 years, said senior author James Van Etten of the University of Nebraska, an expert on algal viruses. Van Etten joined the research four years ago when Johns Hopkins scientists found ATCV-1's DNA sequences in the brain tissue of people who had died with mental disorders such as schizophrenia.

"These viruses are ubiquitous in fresh water ponds and streams throughout the world," Van Etten said. He noted that the virus—previously thought to only infect algae—could make its way into the human body when people swallow water while swimming.There might also be another host in nature, such as mosquito larvae, he said. But the nature of the disease is still in the early stages of analysis.

It is also unknown if the virus's effects on the brain are lasting or temporary. Scientists have long understood that viruses interact with DNA, and further studies could shed more light on the role of the virus on cognition.

"As more studies like this are conducted, I believe we'll find out there's even more interaction between viruses, bacteria and fungi that are either ingested or breathed into our noses and mouths and the overall human condition," said Jordan Josephson, ear nose and throat specialist at Lenox Hill Hospital in New York, who was not involved in the study.

Further information on this study and the virus. From Medical Xpress:

Researchers identify algae-virus DNA in humans

From Newsweek:

American Researchers Discover 'Stupidity Virus'

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Big question: will vitamin D supplementation prevent cognitive decline? And what should be a daily supplement dose for adults? An earlier post cited a Medscape article suggesting that taking 1000 IU of vitamin D3 daily would be a good daily level of supplementation. From Medscape:

Vitamin D Deficiency Predicts Cognitive Decline

A new study supports a link between low levels of vitamin D and increased risk for cognitive decline, prompting calls for clinical trials to test whether vitamin D supplementation may delay or prevent dementia. In a group of cognitively intact older adults, serum 25-hydroxyvitamin D (25OHD) levels below 75 nmol/L at the outset predicted cognitive decline over roughly the next 4 years, independent of other factors.

For this analysis, the researchers looked at data on 1927 community-dwelling elderly individuals (mean age, 73.9 years) participating in the Italian population-based cohort study, Progetto Veneto Anziani (Pro.V.A.).

Dr Toffanello and colleagues say studies are needed to evaluate whether vitamin D supplementation might help to delay the cognitive decline, especially in patients who already have cognitive impairment.

David J. Llewellyn, PhD, from the University of Exeter Medical School in the United Kingdom, who has studied vitamin D and cognitive function but wasn't involved in this study, agrees. He told Medscape Medical News that this new study "effectively replicates" a 2010 study by his group showing a link between low vitamin D levels and an increased risk for cognitive decline. He said the Pro.V.A . study results are also consistent with a study his group published just this year inNeurology. That study suggested older patients with vitamin D levels below 50 nmol/L have about a 122% increased risk for dementia compared with those with higher levels.

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The latest results on this hotly debated subject. The researchers suggest that people instead use "hands free phones with the loud speaker feature". From Medscape:

Long-Term Cell Phone Use Linked to Brain Tumor Risk

Long-term use of both mobile and cordless phones is associated with an increased risk for glioma, the most common type of brain tumor, the latest research on the subject concludes.

The new study shows that the risk for glioma was tripled among those using a wireless phone for more than 25 years and that the risk was also greater for those who had started using mobile or cordless phones before age 20 years.

The recent worldwide increase in use of wireless communications has resulted in greater exposure to radio frequency electromagnetic fields (RF-EMF). The brain is the main target of RF-EMF when these phones are used, with the highest exposure being on the same side of the brain where the phone is placed.

The analysis included 1498 cases of malignant brain tumors; the mean age was 52 years. Most patients (92%) had a diagnosis of glioma, and just over half of the gliomas (50.3%) were the most malignant variety — astrocytoma  grade IV (glioblastoma multiforme). Also included were 3530 controls, with a mean age of 54 years.

The analysis showed an increased risk for glioma associated with use for more than 1 year of both mobile and cordless phones after adjustment for age at diagnosis, sex, socioeconomic index, and year of diagnosis. The highest risk was for those with the longest latency for mobile phone use over 25 years.

The risk was increased the more that wireless phones were used. The odds ratios steadily rose with increasing hours of use...Further, the risk was highest among participants who first used a mobile phone (odds ratio, 1.8) or cordless phone (odds ratio, 2.3) before age 20 years, although the number of cases and controls was relatively small.

As Dr Hardell explained, children and adolescents are more exposed to RF-EMF than adults because of their thinner skull bone and smaller head and the higher conductivity in their brain tissue. The brain is still developing up to about the age of 20 and until that time it is relatively vulnerable, he said.

There was a higher risk for third-generation (3G) mobile phone use compared with other types, but this was based on short latency and rather low numbers of exposed participants, said the authors. 3G universal global telecommunications system mobile phones emit wide band microwave signals, which "hypothetically" may result in higher biological effects compared to other signals, they write. 

Numerous studies have looked at the link between use of wireless phones and brain tumors. Studies by Dr Hardell and his colleagues dating back to the late 1990s have found a connection with mobile and cordless phones. But the INTERPHONE study (Int J Epidemiol 2011;39:675-694; Cancer Epidemiol 2011;32:453-464) failed to find strong evidence that mobile phones increase the risk for brain tumors.

In addition, a large prospective study (Int J Epidemiol 2013;42:792-802) found that mobile phone use was not associated with increased incidence of glioma or of meningioma or non–central nervous system cancers in middle-aged British women.

Pathophysiology. Published online October 28, 2014. Abstract

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Yes! An approach to ADHD that makes sense. Nice piece from Richard A. Friedman, professor of clinical psychiatry and director of the psychopharmacology clinic at the Weill Cornell Medical College. From NY Times:

A Natural Fix for A.D.H.D.

Attention deficit hyperactivity disorder is now the most prevalent psychiatric illness of young people in America, affecting 11 percent of them at some point between the ages of 4 and 17. The rates of both diagnosis and treatment have increased so much in the past decade that you may wonder whether something that affects so many people can really be a disease.

And for a good reason. Recent neuroscience research shows that people with A.D.H.D. are actually hard-wired for novelty-seeking — a trait that had, until relatively recently, a distinct evolutionary advantage. Compared with the rest of us, they have sluggish and underfed brain reward circuits, so much of everyday life feels routine and understimulating.

To compensate, they are drawn to new and exciting experiences and get famously impatient and restless with the regimented structure that characterizes our modern world. In short, people with A.D.H.D. may not have a disease, so much as a set of behavioral traits that don’t match the expectations of our contemporary culture.

From the standpoint of teachers, parents and the world at large, the problem with people with A.D.H.D. looks like a lack of focus and attention and impulsive behavior. But if you have the “illness,” the real problem is that, to your brain, the world that you live in essentially feels not very interesting.The more novel and unpredictable the experience, the greater the activity in your reward center. But what is stimulating to one person may be dull — or even unbearably exciting — to another. There is great variability in the sensitivity of this reward circuit.

These findings suggest that people with A.D.H.D are walking around with reward circuits that are less sensitive at baseline than those of the rest of us. Having a sluggish reward circuit makes normally interesting activities seem dull and would explain, in part, why people with A.D.H.D. find repetitive and routine tasks unrewarding and even painfully boring.

Another patient of mine, a 28-year-old man, was having a lot of trouble at his desk job in an advertising firm. Having to sit at a desk for long hours and focus his attention on one task was nearly impossible. He would multitask, listening to music and texting, while “working” to prevent activities from becoming routine. Eventually he quit his job and threw himself into a start-up company, which has him on the road in constantly changing environments. He is much happier and — little surprise — has lost his symptoms of A.D.H.D.

My patient “treated” his A.D.H.D simply by changing the conditions of his work environment from one that was highly routine to one that was varied and unpredictable. All of a sudden, his greatest liabilities — his impatience, short attention span and restlessness — became assets. And this, I think, gets to the heart of what is happening in A.D.H.D.

Consider that humans evolved over millions of years as nomadic hunter-gatherers. It was not until we invented agriculture, about 10,000 years ago, that we settled down and started living more sedentary — and boring — lives. As hunters, we had to adapt to an ever-changing environment where the dangers were as unpredictable as our next meal. In such a context, having a rapidly shifting but intense attention span and a taste for novelty would have proved highly advantageous in locating and securing rewards — like a mate and a nice chunk of mastodon. In short, having the profile of what we now call A.D.H.D. would have made you a Paleolithic success story.

So if you are nomadic, having a gene that promotes A.D.H.D.-like behavior is clearly advantageous (you are better nourished), but the same trait is a disadvantage if you live in a settled context.

You may wonder what accounts for the recent explosive increase in the rates of A.D.H.D. diagnosis and its treatment through medication. The lifetime prevalence in children has increased to 11 percent in 2011 from 7.8 percent in 2003 — a whopping 41 percent increase — according to the Centers for Disease Control and Prevention. And 6.1 percent of young people were taking some A.D.H.D. medication in 2011, a 28 percent increase since 2007. Most alarmingly, more than 10,000 toddlers at ages 2 and 3 were found to be taking these drugs, far outside any established pediatric guidelines.

Some of the rising prevalence of A.D.H.D. is doubtless driven by the pharmaceutical industry, whose profitable drugs are the mainstay of treatment. Others blame burdensome levels of homework, but the data show otherwise. Studies consistently show that the number of hours of homework for high school students has remained steady for the past 30 years.

I think another social factor that, in part, may be driving the “epidemic” of A.D.H.D. has gone unnoticed: the increasingly stark contrast between the regimented and demanding school environment and the highly stimulating digital world, where young people spend their time outside school. Digital life, with its vivid gaming and exciting social media, is a world of immediate gratification where practically any desire or fantasy can be realized in the blink of an eye. By comparison, school would seem even duller to a novelty-seeking kid living in the early 21st century than in previous decades, and the comparatively boring school environment might accentuate students’ inattentive behavior, making their teachers more likely to see it and driving up the number of diagnoses.

Perhaps one explanation is that adults have far more freedom to choose the environment in which they live and the kind of work they do so that it better matches their cognitive style and reward preferences. If you were a restless kid who couldn’t sit still in school, you might choose to be an entrepreneur or carpenter, but you would be unlikely to become an accountant. 

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Again,the same message: get moving for health, including cognitive function. From Science Daily:

To reap the brain benefits of physical activity, just get moving

Everyone knows that exercise makes you feel more mentally alert at any age. But do you need to follow a specific training program to improve your cognitive function? Science has shown that the important thing is to just get moving. It's that simple.

The study compared the effects of different training methods on the cognitive functions of people aged 62 to 84 years. Two groups were assigned a high-intensity aerobic and strength-training program, whereas the third group performed tasks that targeted gross motor activities (coordination, balance, ball games, locomotive tasks, and flexibility). While the aerobics and strength-training were the only exercises that led to physical fitness improvements after 10 weeks (in terms of body composition, VO2 max, and maximum strength), all three groups showed equivalent improvement in cognitive performance.

The subjects in the third group performed activities that can easily be done at home, which is excellent news for sedentary people who can't see themselves suddenly going to a gym to work out. To improve your cognitive health, you can simply start by doing any activity you like. 

"Our study targeted executive functions, or the functions that allow us to continue reacting effectively to a changing environment. We use these functions to plan, organize, develop strategies, pay attention to and remember details, and manage time and space," explained Dr. Louis Bherer, PhD.

"For a long time, it was believed that only aerobic exercise could improve executive functions. More recently, science has shown that strength-training also leads to positive results. Our new findings suggest that structured activities that aim to improve gross motor skills can also improve executive functions, which decline as we age. I would like seniors to remember that they have the power to improve their physical and cognitive health at any age and that they have many avenues to reach this goal," concluded Dr. Nicolas Berryman, PhD.

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Chocolate lovers are rejoicing! From the NY Times:

To Improve a Memory, Consider Chocolate

Science edged closer on Sunday to showing that an antioxidant in chocolate appears to improve some memory skills that people lose with age. In a small study in the journal Nature Neuroscience, healthy people, ages 50 to 69, who drank a mixture high in antioxidants called cocoa flavanols for three months performed better on a memory test than people who drank a low-flavanol mixture.

On average, the improvement of high-flavanol drinkers meant they performed like people two to three decades younger on the study’s memory task, said Dr. Scott A. Small,a neurologist at Columbia University Medical Center and the study’s senior author. They performed about 25 percent better than the low-flavanol group.

The findings support recent research linking flavanols, especially epicatechin, to improved blood circulation, heart health and memory in mice, snails and humans. But experts said the new study, although involving only 37 participants and partly funded by Mars Inc.,the chocolate company, goes further and was a well-controlled, randomized trial led by experienced researchers.

Besides improvements on the memory test — a pattern recognition test involving the kind of skill used in remembering where you parked the car or recalling the face of someone you just met — researchers found increased function in an area of the brain’s hippocampus called the dentate gyrus, which has been linked to this type of memory.

To consume the high-flavanol group’s daily dose of epicatechin, 138 milligrams, would take eating at least 300 grams of dark chocolate a day — about seven average-sized bars. Or possibly about 100 grams of baking chocolate or unsweetened cocoa powder, but concentrations vary widely depending on the processing. Milk chocolate has most epicatechin processed out of it.

More extensive research is planned. As for why flavanols would help memory, one theory is that they improve brain blood flow; another, favored by Dr. Small, is that they cause dendrites, message-receiving branches of neurons, to grow.

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To celebrate National Nut Day, two articles about health benefits of nuts. From Medical Daily:

National Nut Day 2014: Peanuts, Tree Nuts, And How Each Helps Your Health

“For people who already eat plenty of meat and dairy products…nuts and ‘nutty’ legumes, like Brazil nuts, cashews, peanuts and walnuts, are a good nutritional alternative to meat,” Dr. Donal Murphy-Bokern, independent agri-environmental scientist and author of several studies on food system impacts, said in a statement. Heeding this advice means people can reap the benefits that come with eating nuts — Protein! Fiber! Omega-3 fatty acids! 

Nuts fall into two categories: peanuts (which are really legumes) and tree nuts. The latter includes Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios, walnuts and America’s beloved almonds. ...” And existing research generalizes that eating nuts does everything from reduce risk for a slew of diseases, maintains weight, boosts gastrointestinal and bone health, even adds years to a person’s life.

As previously mentioned, nuts are pretty much equal in terms of calories. There are, however, some nuts that have more heart-healthy nutrients and fats than others. See: pistachios. This particular tree nut is high in healthy fats called monounsaturated fats (MUFA). MUFAs are often associated with belly fat.

One study published in the journal Nutrition found that when middle-aged adults at risk for heart disease and diabetes incorporated more pistachios into their diet, they weighed less and lessened their cholesterol and blood sugar levels after just six months. And a separate study from UCLA found people who regularly ate pistachios lost an average of 10 to 12 pounds. Almonds and cashews are additional nuts high in MUFAs. 

The Harvard School of Public Health reported, “several of the largest cohort studies, including the Adventist Study, the Iowa Women’s Health Study, the Nurses’ Health Study, and the Physicians’ Health Study have shown a consistent 30 percent to 50 percent lower risk of myocardial infarction, sudden cardiac death, or cardiovascular disease associated with eating nuts several times a week.”

Though almonds tend to be associated most with heart health, it’s actually walnuts that take the number one spot. ...Health reported a 2006 Spanish study, which “suggested that walnuts were as effective as olive oil at reducing inflammation and oxidation in the arteries after eating a fatty meal.”

Folate, as defined by Harvard Medical School, is “the naturally occurring form of the vitamin that is in foods or in the blood.” It’s also the vitamin that staves off brain atrophy, or the progressive loss of brain cells over time... A study published in the American Journal of Psychiatry found folate may ward off depression, too. And which nut is super rich in folate? Unsalted peanuts...peanuts are also high in vitamin E and niacin, both of which boost brain health. Hazelnuts and almonds are known to have concentrated amounts of E, too, so either nut is bound to help your noggin.

Study done in mice, but shows benefits of walnuts to brain. From Science Daily:

Fight against Alzheimer's disease: New research on walnuts

A new animal study published in the Journal of Alzheimer's Disease indicates that a diet including walnuts may have a beneficial effect in reducing the risk, delaying the onset, slowing the progression of, or preventing Alzheimer's disease. Research led by Abha Chauhan, PhD, head of the Developmental Neuroscience Laboratory at the New York State Institute for Basic Research in Developmental Disabilities (IBR), found significant improvement in learning skills, memory, reducing anxiety, and motor development in mice fed a walnut-enriched diet.

The researchers suggest that the high antioxidant content of walnuts (3.7 mmol/ounce) may have been a contributing factor in protecting the mouse brain from the degeneration typically seen in Alzheimer's disease. Oxidative stress and inflammation are prominent features in this disease, which affects more than five million Americans.

Walnuts have other nutritional benefits as they contain numerous vitamins and minerals and are the only nut that contains a significant source of alpha-linolenic acid (ALA) (2.5 grams per ounce), an omega-3 fatty acid with heart and brain-health benefits. The researchers also suggest that ALA may have played a role in improving the behavioral symptoms seen in the study.