Exercise Enlarges Brain, Prevents Dementia

Regular physical exercise can help increase the size of the brain section involved in memory, which may in turn help to prevent dementia, a new study finds.

Alzheimer’s disease currently afflicts 5.1 million Americans and that number is growing as the population ages. Therefore, there is great interest in learning what might delay – or even prevent – the onset of the disease.

As part of this effort, scientists are focusing on the effect of exercise on the brain. But while some studies have found that physical activity may help, others have failed to find such an association, they note.

So a research team at UCLA decided to look at data from the landmark Framingham Heart Study, which began 1948,to assess how physical activity affects the size of the brain and also, in turn,how this might impact the risk of developing dementia.

For this study, the UCLA researchers in Los Angeles, Calif. followed an older group of people still living in their community, and followed them for more than a decade to examine the association between physical activity and dementia risk.

They assessed the physical activity indices for both the original Framingham group and their children who were age 60 and older. They examined the association between physical activity and risk of any form of dementia (regardless of the cause) and Alzheimer’s disease for 3,700 participants from both cohorts who were cognitively intact. They also examined the association between physical activity and brain MRI in about 2,000 of the children.

They found that physical activity particularly affected the size of the hippocampus, which is the part of the brain controlling short-term memory. Also, the protective effect of regular physical activity against dementia was strongest in people age 75 and older.

What this study means is that people are too old to exercise for brain health and to stave off the risk for developing dementia, the researchers say of their study, which appears in Journals of Gerontology Series A: Biological Sciences and Medical Sciences.