Different kinds of physical activity shown to improve brain volume, cut Alzheimer's risk in half

This research, conducted by investigators at UCLA Medical Center and the University of Pittsburgh, is the first to show that virtually any type of aerobic physical activity can improve brain structure and reduce Alzheimer's risk. The study, funded by the National Institute of Aging, was published on March 11 in the Journal of Alzheimer's Disease.

The researchers studied a long-term cohort of patients in the 30-year Cardiovascular Health Study, 876 in all, across four research sites in the United States. These participants had longitudinal memory follow up, which also included standard questionnaires about their physical activity habits. The research participants, age 78 on average, also had MRI scans of the brain analyzed by advanced computer algorithms to measure the volumes of brain structures including those implicated in memory and Alzheimer's such as the hippocampus. The physical activities performed by the participants were correlated to the brain volumes and spanned a wide variety of interests from gardening and dancing to riding an exercise cycle at the gym. Weekly caloric output from these activities was summarized.

The results of the analysis showed that increasing physical activity was correlated with larger brain volumes in the frontal, temporal, and parietal lobes including the hippocampus. Individuals experiencing this brain benefit from increasing their physical activity experienced a 50% reduction in their risk of Alzheimer's dementia. Of the roughly 25% in the sample who had mild cognitive impairment associated with Alzheimer's, increasing physical activity also benefitted their brain volumes.

Said lead author Cyrus A. Raji, MD, PhD, of UCLA, "This is the first study in which we have been able to correlate the predictive benefit of different kinds of physical activity with the reduction of Alzheimer's risk through specific relationships with better brain volume in such a large sample."

George Perry, PhD, Editor in Chief of Journal of Alzheimer's Disease, added, "Currently the greatest promise in Alzheimer's disease research is lifestyle intervention including increased exercise. Raji et al present a landmark study that links exercise to increases in grey mater and opens the field of lifestyle intervention to objective biological measurement."

According to the Alzheimer's Association, Alzheimer's disease currently affects 5.1 million Americans and is projected to increase to13.8 million over the next 30 years.

Dr. Raji commented, "We have no magic bullet cure for Alzheimer's disease. Our focus needs to be on prevention."