Exercise and the Aging Brain
|It must be old - it's so wrinkled! |
(Originally broadcast April 2, 2010)
Evidence has been accumulating for a decade now that the best way toforestall or even reverse age-related mental decline is with a regularprogram of exercise. Mental decline is, unfortunately, one of thefeatures of normal aging. Along with losing muscle tissue, jointflexibility and bone density, we lose brain volume as we get older.However, studies have shown consistently that people who exerciseregularly can resist this decline.
Dr. Art Kramer, aneuroscientist and director of the Beckman Institute at the Universityof Illinois, says this was the first indication that aging was not a"one-way street" in which everything gets worse as we get older. He'dshown in studies that sedentary older adults put on regular aerobicexercise programs can improve their scores on cognitive function testsby 15-20%.
Dr. Brian Christie, a neuroscientist in theIsland Medical Program of the University of British Columbia and aprofessor at the University of Victoria, suggests that part of thereason to think mental abilities and fitness could be related is thatthe brain is a very demanding organ, requiring vast amounts of nutrientsand oxygen. Aging-related reductions in fitness could be depriving thebrain of the resources it needs to perform well. There is alsoevidence, that exercise can actually stimulate growth in the brain.Sedentary people put on exercise programs often have increases in brainvolume.
Dr. Laura Baker, a neuropsychologist with theVeterans Administration Healthcare System and the University ofWashington in Seattle, says there are many lines of research beingpursued to understand how exercise helps the brain. One promising oneis evidence that exercise produces growth factors in the brain thatpreserve and protect neurons, and may, in fact, actually stimulateneural stem cells to produce new brain cells - restoring brain tissuethat may have atrophied away.
Dr. Jon Ratey, apsychiatrist from Harvard University, says that this is likely becausestem cells in the brain are stimulated to produce new neurons. Theamount of exercise required seems to be reasonable. Most studiesindicate that forty minutes to an hour of moderately intense aerobicexercise - enough to make you sweat and breath a little harder - threeor four times a week, will help you reap the cognitive rewards.
Article taken from: http://www.cbc.ca/quirks/episode/2012/02/25/february-25-2012/