I keep reading that exercise and diet can prevent Alzheimer's disease, but the different results are confusing. What does the research really mean?

Answer From Jonathan Graff-Radford, M.D.

There are a number of articles that appear quite convincing that certain lifestyle behaviors prevent Alzheimer's disease. Yet, even with these mounting reports, the scientific evidence remains unclear. The most consistent data support cardiovascular exercise and a Mediterranean diet as two lifestyle behaviors that may reduce the risk of Alzheimer's disease.

To understand how lifestyle research is often conducted, it's important to understand the difference between causation and correlation. For example, a study may find that people who eat a diet rich in green leafy vegetables have less cognitive impairment. The relationship between consuming green leafy vegetables and cognitive impairment is a correlation — it doesn't prove that one actually caused or prevented the other. It could be that people who eat green leafy vegetables have other traits working to their advantage.

In another example of correlation, research indicates that other health conditions, such as obesity, diabetes and high blood pressure, might increase the risk of developing dementia. A healthy diet and regular exercise can combat these conditions — which might in turn have an impact on dementia risk.

However, these correlations are crucial for research. And when there are recurring findings over multiple studies, the evidence becomes more compelling — and something worth paying attention to.

There is no downside to eating healthfully, engaging in physical and mental activities, and staying socially connected. Even if they are not yet proved to prevent Alzheimer's disease, they are all extremely good for your mind and body and will improve the quality of your life.

With

Jonathan Graff-Radford, M.D.

Feb. 20, 2018 See more Expert Answers