Mind-Body-Mood Advisor: New Evidence that Exercise Prevents Alzheimer’s Disease

Exercise and being active can prevent Alzheimer's disease, new research suggests. And it's good for your brain even if you're not at risk for dementia.

June 18, 2010

Keep going: There's good reason to believe that exercise protects your brain as you age.

RODALE NEWS, LENOX, MA—If you’re looking for one more reason to get off the couch and get moving, here it is: There is growing evidence that aerobic exercise can help prevent, or at least forestall, the development of Alzheimer’s disease (AD). That's good news for a bit chunk of our aging population; it is estimated that 10 million baby boomers (1 in 8) will develop Alzheimer's. And even if you are an aging couch potato who is not at risk for AD, exercise can help prevent and even reverse many aspects of normal age-related memory decline.

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THE DETAILS: Earlier this month, Rodale.com reported that experts at the National Institutes of Health concluded there is not enough controlled research demonstrating that any lifestyle habits can delay or prevent Alzheimer’s. We explained to you then why that's not cause to give up on lowering your AD risk. And in fact, a recent randomized, controlled study suggests that aerobic exercise can prevent, or at least forestall, the onset of Alzheimer’s in people who are at highest risk for the disease. The researchers in that study looked at a group of elderly people diagnosed with mild cognitive impairment (MCI). People with MCI perform poorly on cognitive tests, but do not show the difficulties in performing tasks of daily living that are characteristic of Alzheimer’s. MCI can be viewed as a precursor to full-blown AD; people with MCI have a five- to tenfold greater risk of progressing to Alzheimer’s.

The research, published earlier this year in the Archives of Neurology, showed that sedentary adults diagnosed with MCI who were enrolled in a six-month exercise program improved their ability to concentrate and carry out a variety of complex tasks, compared with a control group that only completed stretching activities. In fact, members of the stretching-only group declined in their performance on those same tasks during the six months of the study. Laura Baker, PhD, lead researcher on the team from the University of Washington School of Medicine in Seattle, reported that her group conducted many cognitive tests to confirm that what they were observing was real. They found improvements on all measures of executive function, the set of mental skills involved in focusing on and accomplishing complex tasks.

And that's not the only evidence for the benefits of exercise to an aging brain. Previous research done by Art Kramer, PhD, and his colleagues at the University of Illinois, found that older sedentary adults not at risk for AD who engaged in aerobic exercise experienced significant improvement in cognitive function. They found that a 5 to 7 percent improvement in cardiorespiratory fitness led to an increase of up to 15 percent on mental tests.

WHAT IT MEANS: Whether or not you are at risk for AD, exercise is good for your brain. Evidence is growing that exercise can delay, or in some cases, prevent the onset of Alzheimer’s. It is especially crucial for individuals suffering from MCI, who are at greatest risk for developing Alzheimer's. And there's good reason for the phenomenon. Exercise helps to improve cognitive function by increasing blood flow to the brain, and boosting levels of oxygen and nutrients. Exercise also promotes the production of growth factors that stimulate the birth of new brain cells, and promote their connections to other existing brain cells.

Of all the lifestyle practices studied for maintaining healthy brain function, aerobic exercise has been shown to be the most effective.

Here's how you can keep your brain strong and healthy as you age:

• Get moving! Engage in vigorous aerobic exercise, the kind that makes you breathe heavily and makes you sweat, for at least 30 minutes three times a week. Walking, running, biking, and swimming are all excellent aerobic activities. If you’re going to walk, you’ll need to walk briskly, not just stroll, in order to get the full brain-boosting benefit. If you're not in shape for that kind of a workout right off the bat, slowly work up to it.

• Find a way to make your exercise consistent. You want to be in this for the long haul, so come up with an exercise plan that you can stick to. Work out with a partner or trainer, which makes it harder to skip an exercise session, or attend a regular class if you like having company. The idea is to develop an exercise program that is sustainable—and that's enjoyable and poses little risk of injury.

• If you haven’t exercised in a long time, or if you have a serious medical condition that could limit your ability to exercise, get an evaluation by your doctor, and perhaps by a trainer or exercise specialist, which will help you develop an exercise plan that is safe and optimally effective for you.

Jeffrey Rossman, PhD, is a Rodale.com advisor and director of life management at Canyon Ranch in Lenox, MA. His column, “Mind-Body-Mood Advisor,” appears weekly on Rodale.com.