From the American College of Sports Medicine:

Research released this month by the American College of Sports Medicine (ACSM) finds that increasing physical activity may decrease the risk of dementia-related death. The study, titled “Cardiorespiratory Fitness as a Predictor of Dementia Mortality in Men and Women,” appears in this month’s issue of Medicine & Science in Sports & Exercise, the official journal of ACSM. The article is one of the first reports to examine the relationship between objectively measured cardiorespiratory fitness levels and dementia-related deaths in a sample of nearly 60,000 adults.

Public health efforts in the U.S. have triggered gradual declines in deaths associated with heart disease, breast cancer and stroke over the past few years. Deaths related to dementia and Alzheimer’s disease, however, have increased dramatically over the last 15 years, skyrocketing 46 percent between 2002 and 2006.

Researchers conducted baseline examinations and maximal exercise tests for 14,811 women and 45,078 men, ages 20-88 years, at the Cooper Clinic in Dallas. Baseline examinations included self-reported personal and family medical history, a questionnaire on demographic information and health habits, blood chemistry tests, and other clinical measurements. Participants were grouped into one of three fitness categories – low fit, middle fit or high fit – based on their performance on the fitness test.

“A major strength of our study is the use of standardized and objective physical activity measurement,” said Rui Liu, Ph.D., currently a postdoctoral fellow at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health. “Cardiorespiratory fitness is preferable to self-reported physical activity because it is an objective, reproducible measure that is more closely correlated with a person’s usual level of physical activity and many health outcomes.” Liu conducted the analysis as part of her dissertation at the University of South Carolina.

By Dec. 31, 2003 (an average of 17 years after the baseline examinations), there were 4,047 deaths. The National Death Index attributed 164 of these mortalities to dementia (72 vascular dementia and 92 Alzheimer’s disease). Of the 164 individuals whose deaths were related to dementia, 123 were in the low-fit category, 23 were in the medium-fit category, and 18 were in the high-fit category. Compared to the least-fit individuals, those in the medium- and high-fitness groups had less than half the risk of dying with dementia.

“These findings support physical activity promotion campaigns by organizations such as the Alzheimer’s Association and should encourage individuals to be physically active,” said Liu. “Following the current physical activity recommendations from the American College of Sports Medicine will keep most individuals out of the low-fit category and may reduce their risk of dying with dementia.”

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