New studies authored by Ozioma Okonkwo, PhD, an assistant professor of medicine at the University of Wisconsin shows growing evidence that regular exercise can reduce Alzheimer’s symptoms. This research presented at the American Psychological Association’s meeting have found a correlation between physical activity and fewer signs or weaker symptoms of Alzheimer’s and other forms of dementia.

New studies focused on how moderate exercise is tied to “biomarkers” of Alzheimer’s. Physical signs of the disease, such as the buildup of a protein called beta-amyloid in the brain, often show up before symptoms like memory loss. Researchers compared information about people with parents who likely had Alzheimer’s. They found people older than 60 who reported getting at least 30 minutes of moderate exercise five days a week had fewer of those biomarkers and less decrease in memory and cognitive abilities.

Another study presented, looked at people deemed at high risk of Alzheimer’s because of certain genes. It found fewer biomarkers among those who had better aerobic fitness based on their age, sex, body mass index, resting heart rate, and self-reported physical activity habits. In addition, a third study found that one biomarker known as “white matter hyperintensities” was slower to increase in people who were deemed to have high levels of aerobic fitness.

The research also cautioned that the findings just found correlation between this activity and lowering these impacts. Further work is needed to see if exercise is really the reason. The other caveat is these are small studies. They included 317, 95 and 107 participants.

Another study published found patients with a rare inherited, early onset form of Alzheimer’s who exercised for at least 2 1/2 hours a week had better cognitive performance and fewer signs of Alzheimer’s than those who didn’t. It suggested the benefits from exercise seen in people with Alzheimer’s might hold for even those who are at the highest risk of developing the disease.

How does exercise help?

Assuming exercise is a cause of reduced risk, then the key is identifying why that’s the case.

The most common theory is that there’s a benefit from exercise increasing the blood flow, which increases the amount of oxygen that gets to the brain. There’s also the possibility of benefits from improvements in the metabolism of brain cells and from increases in certain hormones and proteins that are good for brain cells.