Does a Healthy Lifestyle Program Improve Brain Function?
Abstract & Commentary
By Norman R. Relkin, MD, Associate Profess or Clinical Neurology and Neuroscience, NewYork-Presbyterian Hospital, Cornell Campus. Dr. Relkin is on the speaker's bureau for Pfizer, Eisai, and Athena Diagnostics, and does research for Pfizer and Merck.
Synopsis: A short-term healthy lifestyle program combining mental and physical exercise, stress reduction, and healthy diet was associated with significant effects on cognitive function and brain metabolism.
Source: Small GW, et al. Effects of a 14-day Healthy Longevity Lifestyle Program on Cognition and Brain Function. Am J Geriatr Psychiatry. 2006;14:538-545.
A training day program designed to modify certain aspects of lifestyle reduces resting prefrontal cerebral metabolism and improves verbal fluency in as little as 2 weeks, according to a study by Small and colleagues. Seventeen non-demented persons (35-69 years old) with mild memory complaints participated in this pilot study. All subjects underwent cognitive testing and FDG-PET studies at baseline and at follow-up 14 days later. Eight of the volunteers were randomly assigned to receive a nurse-administered training program that included 30-45 minutes of daily exercises for memory, physical conditioning, relaxation techniques, and recommendations on a healthy diet. The other subjects were encouraged to pursue their normal lifestyle as a control group. Subjects kept a daily log that permitted assessment of compliance with the training regimen.
After 2 weeks, cognitive testing and PET scans were repeated. There were no significant differences in overall cognitive test scores between controls and subjects in the lifestyle training arm at baseline, or after 2 weeks. Subjective assessment of cognitive performance by the participants was likewise unchanged. However, performance on a letter fluency test (generating words beginning with a specified letter) increased significantly in the lifestyle training group but not in the control group after 2 weeks. In addition, resting cerebral metabolism in the left dorsolateral prefrontal cortex decreased by 5% in the lifestyle training group after 14 days. No changes in cerebral metabolism were observed in the control group. Small et al suggest that the changes in fluency performance and cerebral metabolism may be attributed to effects of healthy lifestyle on the cognitive efficiency of dorsolateral prefrontal regions involved in working memory functions.
Although Small et al emphasize that healthy lifestyle training favorably altered verbal fluency and focally decreased resting metabolism, their findings fail to support their primary hypothesis. The study's aim was to address effects of lifestyle alteration on memory, as evidenced by the recruitment of subjects with self-reported memory complaints. Neither objective nor subjective measures of memory or other aspects of cognition, except verbal fluency, were altered by the lifestyle intervention. The one domain that did improve, verbal fluency, is well known to be affected by one's level of anxiety. The very small effect on resting metabolism, notwithstanding, this study does not support the conclusion that healthy lifestyle training alters brain function significantly on the short timescale of 2 weeks. The basic concept may not be without merit, however, and deserves testing in a larger number of subjects over a much longer period of time.