The recommendation is part of an updated guideline for mild cognitive impairment published in the Dec. 27 online issue of Neurology, the medical journal of the American Academy of Neurology.
"Regular physical exercise has long been shown to have heart health benefits, and now we can say exercise also may help improve memory for people with mild cognitive impairment," says Ronald Petersen, M.D., Ph.D., lead author, director of the Alzheimer's Disease Research Center, Mayo Clinic, and the Mayo Clinic Study of Aging. "What's good for your heart can be good for your brain." Dr. Petersen is the Cora Kanow Professor of Alzheimer's Disease Research.
Mild cognitive impairment is an intermediate stage between the expected cognitive decline of normal aging and the more serious decline of dementia. Symptoms can involve problems with memory, language, thinking and judgment that are greater than normal age-related changes.
Generally, these changes aren't severe enough to significantly interfere with day-to-day life and usual activities. However, mild cognitive impairment may increase the risk of later progressing to dementia caused by Alzheimer's disease or other neurological conditions. But some people with mild cognitive impairment never get worse, and a few eventually get better.
The academy's guideline authors developed the updated recommendations on mild cognitive impairment after reviewing all available studies. Six-month studies showed twice-weekly workouts may help people with mild cognitive impairment as part of an overall approach to managing their symptoms.
Dr. Petersen encourages people to do aerobic exercise: Walk briskly, jog, whatever you like to do, for 150 minutes a week -- 30 minutes, five times or 50 minutes, three times. The level of exertion should be enough to work up a bit of a sweat but doesn't need to be so rigorous that you can't hold a conversation. "Exercising might slow down the rate at which you would progress from mild cognitive impairment to dementia," he says.
Another guideline update says clinicians may recommend cognitive training for people with mild cognitive impairment. Cognitive training uses repetitive memory and reasoning exercises that may be computer-assisted or done in person individually or in small groups. There is weak evidence that cognitive training may improve measures of cognitive function, the guideline notes.
The guideline did not recommend dietary changes or medications. There are no drugs for mild cognitive impairment approved by the U.S. Food and Drug Administration.
More than 6 percent of people in their 60s have mild cognitive impairment across the globe, and the condition becomes more common with age, according to the American Academy of Neurology. More than 37 percent of people 85 and older have it.
With such prevalence, finding lifestyle factors that may slow down the rate of cognitive impairment can make a big difference to individuals and society, Dr. Petersen notes.
"We need not look at aging as a passive process; we can do something about the course of our aging," he says. "So if I'm destined to become cognitively impaired at age 72, I can exercise and push that back to 75 or 78. That's a big deal."
The guideline, endorsed by the Alzheimer's Association, updates a 2001 academy recommendation on mild cognitive impairment. Dr. Petersen was involved in the development of the first clinical trial for mild cognitive impairment and continues as a worldwide leader researching this stage of disease when symptoms possibly could be stopped or reversed.
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