Two studies published in this week's Journal of the American Medical Association add to evidence that long-term lifestyle habits may reduce the risk of mental decline in old age.
The first study, a long-term look at 1,880 elderly people in New York City, found that a Mediterranean-type diet and physical activity each were linked to less risk for Alzheimer's disease. The Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Medical Center released the data as part of a larger research project on aging.
Starting in 1992, researchers at Columbia University monitored elderly patients every 18 months for diet, exercise and mental health, in addition to a number of controls including age, sex and education. "This is one of the first studies to tease apart the independent contributions of diet and exercise for dementia prevention," says Ronald Petersen, director of the Alzheimer's Disease Research Center at the Mayo Clinic in Rochester, Minn., who was not involved in the research. "It suggests that aging need not be a passive process."
These studies are observational and not definitive, but they hint at what might reduce the chances of Alzheimer's or dementia. In the Columbia research, those who adhered most closely to the diet reduced their risk for Alzheimer's by 40%, while those with the highest physical activity decreased their risk 33%, compared with people who didn't adhere closely to the diet or were not physically active.