Sunday, April 22, 2012
Can You Grow Your Brain?
Does exercise lead to a better brain? According to an article in today's New York Times Magazine, it can. In a recent blog, I discussed a number of studies that show that exercise can elevate mood and can have the same medicinal effect as antidepressants in treating mild to moderate depression. So you don't need to be a Rhodes Scholar to appreciate the therapeutic benefits of exercise. However, we apparently do need a scholar by the name of Justin Rhodes to tell us why. Dr. Rhodes, a psychology professor at the University of Illinois conducted an interesting set of experiments with mice that showed that among four sets of mice, those who engaged in the most exercise saw an increase of new neurons or brain cells, even more than those who received the most mental stimulation.
The credit for this effect is partially given to something called B.D.N.F. When I first saw this acronym, I immediately thought that it stood for Brains Do Need Fun. Alas, it actually stands for the more mundane Brain Derived Neurotrophic Factor, which in layman's terms means it makes brains grow. I still like mine better because fun does make everything better, but it's still good to hear that we can potentially grow our brains. Scientists, however, believe that the growth from exercise in mice is not solely from B.D.N.F, because they think that the process must include other complex biochemical processes and genetic cascades.
I am a huge believer in the benefits of exercise not only for mental health, but for heart health as well. Every study I've ever read supports that conclusion. However, I have my usual set of problems with these mice studies. First, it was done in mice, which means it is not necessarily extrapolatable to humans. In fact, scientists are unable to study similar affects in humans, although studies do show an increase in B.D.N.F levels after exercise.
Second,and more importantly, if exercise increases brain size and density, wouldn't professional athletes have bigger, healthier, and more durable brains than the rest of us? I've yet to read or hear of a study that showed that athletes are smarter, develop less Alzheimer's, and in general have healthier brains than the rest of the population. Have you? Perhaps there is a threshold regarding the effects of exercise? Perhaps, when you start from zero and steadily increase, you experience heart and brain benefits up to a point, and then further increases lead to deterioration? That theory would be consistent with a couple of studies I've read that showed that professional athletes all develop some form of heart damage from their high levels of exertion.
Now please don't us this blog as an excuse to avoid exercise. It's not. The average person is no more likely to reach that turning point when exercise becomes potentially harmful than they are to grow their muscles "too big" in a gym. Professional athletes generally waive caution in pursuit of excellence, and most people will never get close to that level of endurance (nor should they).
Physical activity is the hallmark of health and longevity. All studied centenarian communities are predicated on constant physical activity. If that's not possible for you due to the nature of your work or other circumstances, then schedule, if possible, robust exercise for ideally 30 minutes a day. If you miss a day, ignore it and do better the next day Even ten minutes of brisk activity a day was shown in one study to decrease heart attack risk by 50%. (Not a perfect study, but as you may have learned by now they never are, are they?) Minimally, get out of your chair every 55 minutes ans either take a walk, go up and down stairs, or do some jumping jacks.
Nevertheless, how do you know if your exercise is adequate for good heart and brain health? My rule includes singing. For endurance related aerobic exercise, try to get to the point where singing becomes difficult. Not where your singing becomes difficult for others, which may always be the case, but for you. By the way, if these words compel, you to start exercising or increase your level of exercise, please consult with your personal physician before doing so.
Ultimately, I can't tell you if the brain is figuratively or literally like a muscle that grows stronger with exercise, but I'm pretty sure that like a muscle, if you don't use it, you will lose it.