Lately there has been a great deal of controversy about the ethics and environmental impact of consuming shark fin, an Asian delicacy, but there may be an even better reason to stay away from it: researchers at the University of Miami have found that shark fin contains high concentrations of a neurotoxin that’s implicated in degenerative brain diseases like ALS (Lou Gehrig’s disease) and Alzheimer’s.

The Miami team tested seven species of sharks found in local Florida waters, and found that all contained extremely high concentrations of the neurotoxin β-Methylamino-L-alanine (BMAA.) Previous studies have observed that patients suffering from neurodegenerative disorders have high concentrations of BMAA in their brains, whereas healthy people have little or no BMAA present. The sharks studied were found to have comparable levels of BMAA as human sufferers of Alzheimer’s and ALS.

Further, research by Paul Cox had previously concluded that disproportionate numbers of indigenous people in Guam suffer from dementia and ALS–which was linked to eating fruit bats with high levels of BMAA. The levels of BMAA in the Guamanian bats and the Florida sharks are similar. Based on their own research and these previous studies, the Miami group warns that ingesting shark fin soup, or other shark products like dietary supplements, may contribute to the development and severity of neurodegenerative disease.

To learn more, you can read the press release here.

A recent study published in the New England Journal of Medicine showed that practicing the meditative Chinese martial art tai chi may help alleviate Parkinson’s symptoms, and resistance training might also help with certain aspects of the disease. The study, conducted by scientists from the Oregon Research Institute, compared three different types of interventions in the study. One group practiced tai chi, another did resistance training, while the third stretched in a classroom setting. The interventions were practiced twice a week for an hour each time.

Following twenty four weeks of this training regimen, the research team found that those in the tai chi group had improved strength, balance, reach, and control of movement. The resistance training group had some gains, but the gains were not as large as the tai chi group. Both the tai chi group and the resistance training group experienced fewer falls than the stretching group.

This study is not a huge surprise, as it builds on previous research in this general area. For example, a recent study in Age Ageing demonstrated that tai chi can improve balance and proprioception in visually impaired adults over 70. Tai chi has been proven to be effective for pain management as well. A study in the New England Journal of Medicine showed that tai chi may also ease pain in fibromyalgia sufferers. Another study showed that tai chi can be effective for managing lower back pain.

If you are interested in finding a tai chi class, you may want to try the list at the World Tai Chi Day website.

We’ve long heard about the brain-boosting powers of things like blueberries, nuts, wine, and chocolate – but is milk the newest brain food? A new study of nearly 1,000 people suggests that it may be.

The study, a collaboration between researchers from the University of Maine and the University of South Australia, found that “participants who consumed dairy products at least once per day had significantly higher scores on multiple domains of cognitive function compared with those who never or rarely consumed dairy foods, adjusting for cardiovascular risk factors, lifestyle and dietary factors.” They also found that, in general, “…frequent dairy food intake is associated with better cognitive performance but underlying causal mechanisms are still to be determined.” In other words, people who consume more dairy do better than non-dairy consumers, but it’s not 100% clear why.

The study showed that the relationship between dairy consumption and healthy cognition was linear – so the more dairy consumed, the better the cognitive outcomes. That is, people who consumed dairy every day did better than people who consumed it weekly, and those people did better than those who consumed dairy very infrequently.

The researchers plan to take the next step of testing specific dairy products, taking into account fat and vitamin content of each, and enhance the breadth of the neuropsychological testing battery involved. Nonetheless, this early finding is certainly exciting to those of us who are interested in the brain-boosting effects of certain foods.

I recently saw a research finding from 2009 that was pretty interesting. Canadian scientists studied people who self-identified as “morning people” or “night people” and found striking differences in brain activity patterns between the two groups. They noticed that neuronal excitability started high and decreased throughout the day for morning people, and started low and increased for night people.

They also measured spinal cord response, which they found increased throughout the day in everyone. They posited that this might mean that night people are able to increase strength to its maximum potential better than morning people, because their brain and spinal cord activity are in sync, whereas the brain and spinal cord activity of morning people are off-kilter with one going up while the other goes down.

The researchers are hoping these findings could help find ways to help shift workers or others who have to adjust their schedules contrary to their natural inclinations. You can learn more about the study here.

A new study has found that dogs learn to read the body language of humans in much the same way that human infants do. The study, conducted in Hungary, showed that dogs behaved in a way that is “functionally similar to a 6-month-old, to a 1-year-old,” according to the lead researcher.

First, dogs watched a human who looked them in the eye while addressing them, then shifted their gaze. The dogs followed the human gaze. When the human didn’t look them in the eye while addressing them, the dogs didn’t follow the gaze. Previous studies in human babies have shown the same behavior. The researchers noted that this behavior was not found in other domesticated animals, like goats.

You can see the abstract from Current Biology here.

A new study published in Neurology has found that older people with higher concentrations of vitamins B, C, D, and E may have better mental functioning. The study was conducted in people who had an average age of 87, and noted that the more vitamins found in the subjects’ bloodstream, the better they performed on mental exercises and tests.

The study yielded two other preliminary findings: first, that Omega-3s were associated with better executive functioning, and second, that people with more trans fats in the blood had lower cognitive scores overall.

It’s important to note that this was a relatively small study, involving only 104 people, so a larger study (ideally with thousands of people) will be necessary to bear these findings out.

You can read more about these findings from the National Institutes of Health website.

With all of the complex brain science findings out there, I really enjoyed this TED talk from neuroscientist Daniel Wolpert that goes back to one of the most fundamental questions about brains: why do we have them at all? Wolpert argues that the only reason we evolved our brains is because we had to move, not because we had to think or feel. This is a fun and thought-provoking talk that may get you thinking about your brain in a markedly different way! Incidentally, Wolpert is a compelling and humorous speaker, too.

For the past two holiday seasons we have partnered with OneSight—a terrific charity organization that provides eye care to those in need through outreach, research and education. Our previous holiday donations have allowed OneSight to recycle thousands of pairs of glasses for people in need. This holiday season we hope to match that—or do even better!

For each brain fitness purchase made between now and December 14, we’ll donate a portion of the proceeds to OneSight, a charity that provides eye care for people who can’t afford it. To learn more about our partnership, you can visit this page.

Over 300 million people worldwide suffer from poor vision simply because they do not have access to or cannot afford care. Poor, uncorrected vision can inhibit a child’s ability to learn and can rob adults of independence and quality of life. One of our scientists, Dr. Peter Delahunt, has written on this blog before about the problems of having incorrectly prescribed glasses and discusses a study that shows that correctly prescribed glasses can improve quality of life. In some countries, a pair of eyewear costs more than a month’s salary.

Over the past 23 years, OneSight’s volunteers have provided free eyewear and vision care to more than seven million people. In addition to our monetary donation, we host an ongoing eyeglass drive at our office – with almost 100 pairs of eyeglasses donated and counting! Those old glasses in the back of your drawer can be recycled into a life-changing gift for someone in need. To learn more about where to donate your old glasses, or to find resources to help you set up a drive to collect eyeglass donations, visit the glasses donation page on OneSight.org or see this article for other organizations that recycle used glasses.

Happy holidays to everyone from Posit Science!

“Chemobrain” or “chemofog” is a condition that affects cancer survivors who have undergone chemotherapy. Dozens of studies have shown that post-chemotherapy, patients may experience a decline in cognitive performance and memory, and many doctors have long believed chemobrain to be a significant problem for cancer patients. (To learn more about chemobrain, I recommend this in-depth article.) Despite this significant body of evidence, though, some medical professionals continue to dismiss patient claims of cognitive decline as exaggerated or unrelated to their condition.

However, a new study from Stanford University has used brain scans to definitively show that post-chemotherapy, many women show cognitive deficits in the areas of attention, memory, and planning.

The good news about chemobrain: researchers agree that the brain’s plasticity means that it’s largely reversible, with the right kind of intervention. A study from 2008 found that people experiencing chemobrain were successfully rehabilitated after using the Posit Science Brain Fitness Program. The active participants’ speed of processing, listening, and overall quality of life improved significantly after training.

We have additional  information about chemobrain, including survivor stories and links to science studies, on this page.

Do long, dark winter nights get you down? For those affected with the form of depression known as Seasonal Affective Disorder (SAD), the winter can be a difficult time. The National Health Service of the UK estimates that 7% of Britons are affected by SAD, and U.S. estimates hover between 4% and 6%. According to Mayo Clinic, SAD occurs most commonly during the winter months and happens because of an imbalance of melatonin production, which can disrupt the body’s internal clock and lead to depressive symptoms like anxiety, lack of concentration, irritability, and hopelessness.

The most common therapy to date involves prolonged exposure to bright light (30 minutes at 10,000 lux – with the average office lighting being around 400 lux, and a bright sunny day being between 10,000 and 25,000 lux.) However, a new study from a Finnish medical company has found that a 12 minute session of light focused in the ear canal may be just as effective in treating SAD. The researchers channel the light into photosensitive areas of the brain via the ear canal via a headset device for 12 minutes a day. You can learn more about the device and the corresponding clinical trials in this article.