Mediterranean Diet, Physical Activity, and Risk for Alzheimer’s
Studies reported in this week’s Journal of the American Medical Association (August 12, 2009) support the relation of physical activity and the Mediterranean diet to reduced risk for Alzheimer’s disease. The first study, by Scarmeas and his colleagues, showed that persons who report following the Mediterranean diet and who are more physically active were less likely to develop Alzheimer’s disease over several years. The average age of the participants was 77 years, so this group (called the Northern Manhattan cohort) would have been at higher risk than younger individuals.
The second study, by Feart and her colleagues, looked at adherence to the Mediterranean diet and risk for having problems on certain mental ability tests. Here again, the study suggests that following the Mediterranean diet was associated with a reduced risk of developing certain kinds of cognitive problems.
The study was discussed by Dr. Nancy Snyderman on the Today Show. You can find a link to a page that will let you see the segment from the show here. (Look for a link to “Study: Mediterranean diet cuts Alzheimer’s risk.” You also have to watch a commercial; that’s NBC, not me). I think that she may overstate the case based on the research; there’s a very nice editorial in this same issue of the Journal by well-known neurologist David Knopman. He points out a number of possible reasons for these findings that might affect the conclusion that the Mediterranean diet and exercise reduce the risk of Alzheimer’s. He suggests we should “nibble and savor” the results of these studies, not “swallow them whole.”
It’s still premature to be sure that following the Mediterranean diet or being physically activity will prevent Alzheimer’s disease. Given what we know about the relation of cardiovascular health and risk for Alzheimer’s, and what we know about diet and exercise and cardiovascular health, though, I think it’s a good idea to pay close attention to your diet and to exercise safely.