Researchers found that after just 14 days of following healthy lifestyle strategies, study participants' brain metabolism decreased in working memory regions, suggesting an increased efficiency -- so the brain didn't have to work as hard to accomplish tasks.
For the two-week study, 17 subjects with normal baseline memory performance scores were randomly assigned to two groups: a control group did not make any behavior modifications, while a test group incorporated healthy longevity strategies to improve physical and mental function.
Details of the healthy strategies employed in the study also are highlighted in Small's new book to be published today, "The Longevity Bible: 8 Essential Strategies for Keeping Your Mind Sharp and Your Body Young" (Hyperion, New York, 2006).
Participants on the healthy longevity plan incorporated the following into their daily routine:
--To stimulate the brain, memory exercises such as crossword puzzles and brainteasers were conducted throughout the day.
--To improve physical fitness, participants took daily walks, which have been found to increase life expectancy and lower the risk of Alzheimer disease.
--To improve their diet, study participants on the plan ate five small meals a day, which prevents drops in blood glucose levels since glucose is the main energy source for the brain. In addition, they ate a balanced diet full of omega-3 fats, antioxidants and low glycemic carbohydrates like whole grains.
--To manage stress, participants performed daily relaxation exercises. Small notes that stress causes the body to release cortisol, a hormone that can impair memory and damage brain memory cells.
Brain function was tested before and after the 14-day study, using positron emission tomography (PET) scans to measure brain activity. Participants who followed the healthy longevity lifestyle plan demonstrated a five percent decrease in brain metabolism in the part of the brain directly linked to working memory called the dorsal lateral prefrontal cortex.
"The finding suggests that for participants who had followed the healthy longevity program, the brain functioned more efficiently and didn't need to use as much glucose to perform effectively," Small said.
In addition, compared to the control group, participants also performed better in verbal fluency, a cognitive function controlled by the same brain region.
"The research demonstrates that in just 14 days, simple lifestyle changes can not only help overall health, but also improve memory and brain function," Small said. "Our next step is to assess the individual effects of each lifestyle strategy, which may help us develop an optimal combination.