You may recall the results of a Canadian study I posted some time ago that demonstrates beyond a doubt how regular exercise helps patients ward off Alzheimer’s disease as they age. A new study by Johns Hopkins researchers bolsters these findings, but in a different way than before.

Seems the variety of leisure and physical activity one engages in — not its intensity in terms of calories burned — may reduce dementia risk in older people, according to researchers. The study tracked the health of some 3,400 men and women older than age 64 who participated in the Cardiovascular Health Cognition Study from 1992-2000 and didn’t have dementia at the onset of the study.

Each patient was asked to fill out a questionnaire about the frequency and duration of the 15 most common types of physical activity in older adults, including walking, household chores, gardening, hiking, jogging, biking, exercise cycling, dancing and aerobics. Then, researchers created an activity index, calculated as the number of different activities each subject participated in over the previous two weeks.

Scientists found 480 new cases of dementia over an average of 5.4 years of follow-up. Among these patients, dementia occurred less frequently in those participating in more activities relative to those who participated in fewer activities. In fact, more than half of the dementia cases involved patients who participated in two or fewer activities.

One important caveat: The association between variety of activity and dementia risk didn’t hold up in those with the so-called APOE-4 genetic predisposition to the disease found in about a third of Alzheimer’s patients.

If you read my eHealthy news You Can use newsletter regularly, however, you know exercise is only one of several tools at your disposal on my Web site to easily, safely and inexpensively blow away Alzheimer’s disease.

American Journal of Epidemiology, April 1, 2005, Vol. 161, Issue 7: 639-651

EurekAlert April 14, 2005