John Oró, MD
The authors of a new report published in the Mayo Clinic Proceedings reviewed 1,600 articles on the role exercise in cognitive function and found 130 studies pertinent to the issue. According to Medscape Neurology, the lead author, neurologist J. Eric Ahlskog, MD, PhD, notes:
Normal aging is associated with brain shrinkage, and this appears to be primarily mediated by progressive loss of synapses and related neuronal connections (the 'neuropil').
Dr. Ahlskog summarized the findings:
We concluded that you can make a very compelling argument for [aerobic] exercise as a disease-modifying strategy to prevent dementia and mild cognitive impairment, and for favorably modifying these processes once they have developed.
While the type and amount of exercise varied among the studies, to Dr. Ahlskog, the studies suggests increasing "the heart rate to about 60% of maximum" in several sessions for a total about 150 minutes each a week. Even though the literature on resistance training was "less extensive", Dr. Ahlskog noted it was also beneficial. Cyrus Raji, MD, PhD of the University of Pittsburgh, not a participant in the study, concurred:
While the majority of the evidence shows that aerobic physical activity is the best type of physical activity for this purpose, resistance training with weights may also be helpful.
Dr. Raji's impression of the study:
This paper nicely summarizes all of the latest evidence showing how regular physical activity can promote better brain health with aging and reduce the risk of Alzheimer's disease.