Older people who get regular physical activity, even through relatively light pursuits like gardening or golf, have bigger brains compared to inactive older people, a new study suggests. The finding adds to a mountain of research showing that physical activity helps prevent brain shrinkage and slow the effects of brain aging that lead to cognitive decline and dementia.
In the new research, brain scans of 1,557 older people, average age 75, revealed that the most-active third of them had a brain volume 1.4% greater than the least-active third, a difference equivalent to being four years younger, the researchers say. People in the most-active group reported getting either seven hours of low-intensity physical activity weekly (things like gardening, dancing, golf, or bowling), or four hours of moderate activity (such as tennis, swimming, or hiking), or two hours of high-intensity activity (such as jogging or handball).
Research has shown that healthier lifestyles can lower the risk of developing dementia, and several studies have shown that moderate physical activity, including brisk walking, improves brain power. One study last year found that people who exercised moderately for six months did far better than sedentary people on tests measuring the ability to pay attention, organize tasks, and achieve goals. The effects were found for all age groups. The people who exercised were testing as if they were about 10 years younger at age 40 and about 20 years younger at age 60.
The benefits of exercise can be starkly visible in the brain. A recent study took brain scans of people who did moderate physical activity on a treadmill three days a week and compared them to a sedentary control group. All the people had risk factors for Alzheimer’s but were not yet showing signs of the disease. After six months, people who had exercised had increased levels of brain glucose metabolism in a part of the brain linked to Alzheimer’s — a good sign of healthy neurons. And they did better on tests of cognition for things like planning, focusing attention, and juggling multiple tasks.
There is good evidence for the value of exercise in midlife, but it is encouraging that there can be positive effects on the brain in later life as well.
