Increase Physical Activity to Reduce Dementia Risk

We've long known that one of the ways to reduce your risk of developing Alzheimer's and other types of dementia is to choose a healthy lifestyle. This includes eating brain-healthy foods and regular physical exercise. But a study published in the Journal of Alzheimer's Disease in March 2016 found that almost any kind of physical activity — not just high-level aerobics or weight resistance exercises — reduced the risk of dementia.

This is important because, as the study's authors point out, "approximately 13 percent of AD cases worldwide may be attributable to sedentary behavior" (Journal of Alzheimer's Disease. 

The research looked at 876 participants with an average age of 78 who have been involved in the Cardiovascular Health Study, an ongoing research project that was begun in 1989. Over the years of the study, participants had magnetic resonance imaging (MRIs) of their brains, they tracked their physical activity and underwent repeated cognitive testing. The different kinds of physical activity tracked were measured in calories burned and included:

• swimming
• hiking
• aerobics
• jogging
• tennis
• racquetball
• walking
• gardening
• mowing
• raking
• golfing
• bicycling
• dancing
• calisthenics
• riding an exercise cycle

After the data was collected, researchers looked at what — if any — correlations were found between physical activity, brain volume, and cognitive functioning.

Several conclusions were reached based on the results of the study.

1) Greater levels of physical activity in the two weeks prior to an MRI were associated with an increase in the brain's gray matter volume on MRIs. This includes the hippocampus, which has been strongly associated with memory. Atrophy (shrinkage) in the brain has been connected with a decline in cognitive functioning, while other research has found that the reverse is also true.

2) Brain volume also increased for those participants who had mild cognitive impairment (MCI). MCI increases the chances of progressing to Alzheimer's disease, although not everyone with MCI will progress to dementia.

3) Participants in this study who experienced an increase in brain volume also decreased their risk of developing Alzheimer's disease by 50 percent. This means that their risk of dementia was cut in half.

Keep moving. This research, along with other studies, demonstrates that almost any physical activity — not just the kind you go to the gym for — can help keep your body and your brain more healthy. While there's no guarantee for completely preventing Alzheimer's and other types of dementia, staying active reduces the risk. And, since we don't yet have a cure or effective treatment, risk reduction is of utmost importance.