NEW YORK (Reuters Health) - Staying physically active can help keep adults fit as they grow older, but, contrary to what some may think, it may not protect against mental decline, according to a new study.

Previous researchers have reported that physical activity may help guard against stroke and coronary heart disease, both of which may be associated with the development of dementia.

In the current study, Sturman and her team analyzed 1993 to 2003 data from the Chicago Health and Aging Project, a large ongoing study of risk factors for chronic disease among elderly adults.

The report indicates physical activity did not appear to be associated with higher mental function at the start of the study. Further, although increased hours of physical activity appeared to be associated with slower rates of mental decline, this association did not hold true when the seniors' participation in mentally stimulating activities was taken into consideration, the report indicates.