Cutting Edge information about Exercise and the Brain
I recently read the book, Grain Brain by David Perlmutter, MD. He is a board-certified neurologist as well as a fellow of the American College of Nutrition (the only doctor in the country with both of these credentials). He is also a founding member and fellow of the American Board of Integrative and Holistic Medicine. The credentials are impressive because they bring a nice blend of Western Medicine with great expertise along with alternative and holistic medicine. His book is phenomenal in bringing us new information about what impacts our brain and how we have real control over brain diseases.
One part of the book that was stunning was the impact of exercise on the brain. Perlmutter writes that the act of moving our bodies will do more for our brain than any riddle, puzzle, math equation or book. He gives us evidence that when you exercise you exercise, your genetic makeup. Aerobic exercise first turns on the genes that are linked to longevity but also targets the gene that codes for brain-derived neurotrophic factor (BDNF) which is the brain’s growth hormone. Aerobic exercise has been shown to increase new brain cells in the memory center and reverse memory decline in older adults. (Perlmutter, 2013)
We have known that exercise is good for the brain for some time now. The thinking was that it increased the blood flow to the brain and created more neurons. However, the research from the last decade is coming together (which Perlmutter brings together in his book) to give us much more dynamic information about the relationship between physical fitness and mental fitness. Gretchen Reynolds from the New York Times states, “It is the relationship.” (Reynolds, 2012) Again we are finding that it is all about the brain. What the research is showing us, according to Perlmutter, is that exercise, “appears to build a brain that resists physical shrinkage and enhances cognitive flexibility”. And because of this, he states, we may have no greater tool at our fingertips than exercise and physical movement.
Perlmutter lists five benefits of exercising that may be new information. These are controlling inflammation, increasing insulin sensitivity, influencing better blood sugar control, expanding the size of the memory center and boosting levels of BDNF (the brain growth hormone). Higher levels of the brain growth hormone decrease our appetite. He expands on the idea that new neurons not only are created through exercise but also organized into new networks that fit into our established network. He makes the point that new neurons are great but don’t make us smarter unless we are able to interconnect them into our existing neural networks.
Researchers have also been looking at the effects of physical exercise in people who are already at risk for brain disorder and disease. This is probably an area of mutual concern. In a 2011 study conducted by Harris Interactive for the MetLife Foundation it was found that 31% of people fear dementia more than death or cancer. (MetLife Foundation, 2011) So pay attention. Perlmutter is giving us some very empowering information. He reviews the research from a study from Rush University’s Memory and Aging Project. This project looked at the effects of daily physical exercise on one’s risk for Alzheimer’s disease. The results show that the individual in the lowest 10% of daily physical activity had a 230% increased risk of developing Alzheimer’s disease compared to those in the highest 10% of physical activity. When they looked at the data in terms of intensity of physical activity, the results were even more dramatic. They found that the risk of Alzheimer’s was nearly tripled in those who had the least amount of exertion. (Buchman, 2012)
In another study that Perlmutter reviewed from the Journal of the American Medical Association, Nicola Lautenschlager of the University of Western Australia found that elderly individuals engaged in regular physical exercise for a 24 week period had an 1800% improvement in memory, language ability, attention and other important cognitive functions compared to the counterpart control group. (Lautenschlager, 2008) (Perlmutter, 2013)
Although there have been studies that show cognitive benefits among older people who just lifted weights for a year, most of the studies at this time and all animal experiments have involved aerobic activity to get the heart pumping on a regular basis. Perlmutter suggests five days a week for at least 20 minutes per session. There is much more information to glean from this chapter on exercise and its benefits to the brain. This is only one chapter of a book that is filled with information that is hard to ignore if we want to take charge of our health and well-being.
Buchman, e. a. (2012, April). Total daily activity and the risk of AD and cognitive decline in older adults. . Retrieved from sciencedaily.com.
Lautenschlager, N. T. (2008). Effect of physical activity on cognitive function in older adults at risk for alzheimer disease: a randomized trail. JAMA 300, 1027-37.
MetLife Foundation. (2011). What america thinks: MetLife foundation alzheimer’s survery. Retrieved from metlife.com.
Perlmutter, D. (2013). Grain Brain. New York: Little, Brown and Company.
Reynolds, G. (2012). How exercise could lead to a better brain. New York Times Magazine.
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