An active lifestyle has long been promoted as a way to keep the heart pumping strong. Now new research shows that physical activity may help to keep the brain robust as well, preserving areas critical for thinking and memory and possibly even helping to ward off Alzheimer’s disease in old age.
Earlier studies have linked activities like walking and ballroom dancing to a lower risk for dementia. Exercise is known to boost cardiovascular health, and what’s good for the heart is good for the brain, the thinking goes.
Now scientists at the University of California, Los Angeles, have examined the effects of remaining active directly on the brain. For the report, they looked at detailed records of 876 older adults, average age 78, over decades. Some had Alzheimer’s disease or serious memory problems, while others were cognitively alert. Along with medical reports, the records included information on how often each participant engaged in activities like gardening and yard work, bicycling or riding an exercise bike, dancing, and recreational activities like golfing, walking or tennis.
"We had 20 years of clinical data on this group, including body mass index and lifestyle habits," said Dr. Cyrus Raji, a radiology resident at U.C.L.A, one of the study leaders. "We drew our patients from four sites across the country, and we were able to assess energy output in the form of kilocalories per week." The findings were reported at the annual meeting of the Radiological Society of North America.
Using specialized brain scans, the researchers created 3-D maps of the brain, including areas of gray matter critical for thinking and memory. "Gray matter volume is a key marker of brain health. Larger gray matter volume means a healthier brain. Shrinking volume is seen in Alzheimer's disease," Dr. Raji said.
The researchers found that those men and women who were most active had more gray matter in parts of the brain critical for memory and thinking. They took into account such factors as age, head size, body mass index, and education, which can influence Alzheimer’s risk.
"The areas of the brain that benefited from an active lifestyle are the ones that consume the most energy and are very sensitive to damage," Dr. Raji said. "What struck me most about the study results is that it is not one but a combination of lifestyle choices and activities that benefit the brain."
Dr. Raji said the benefits of an active lifestyle on the brain were likely due to improved blood vessel health. "Virtually all of the physical activities examined in this study are some variation of aerobic physical activity, which we know from other work can improve cerebral blood flow and strengthen neuronal connections," he said. Although more research is needed in this area, “our initial results show that brain aging can be alleviated through an active lifestyle," he said.
In a separate study also presented at the Radiological Society of North America’s annual meeting, scientists at the Medical University of South Carolina in Charleston reported that men and women with Alzheimer’s disease had different patterns of gray matter loss, or atrophy.
"We found that the extent and distribution of regional gray matter volume loss in the brain was strongly influenced by gender," said lead researcher Dr. Maria Vittoria Spampinato. "The female patients in our study initially had more gray matter atrophy than the male patients, but over time, the men caught up. In the men, the disease developed more aggressively in a shorter period of time."
The findings could have implications for monitoring the effects of new Alzheimer’s drugs on the brain. "Knowing the difference between the male and female patterns of atrophy will help researchers better decipher a patient's response to drug therapy," Dr. Spampinato said.
Source: Cyrus, Raji, M.D., Ph.D., H. Michael Gach, Ph.D., Owen Carmichael, Ph.D., et al: Annual meeting of the Radiological Society of North America