Two studies recently published in the journal JAMA analyzed the influence of lifestyle factors on cognitive outcomes. Researchers discovered that physical activity and dietary supplementation are unlikely to protect against cognitive decline; however, they conclude that these results shouldn’t lead to pessimism involving lifestyle factors amongst elderly adults.
The two randomized controlled studies involved over 5,800 people.
The diet study involved participants from the Age-Related Eye Disease Study 2 who were at risk for developing age-related macular degeneration. Participants were randomly assigned to long-chain polyunsaturated fatty acids (1 gram) and/or the dietary supplements lutein (10 milligrams) or zeaxanthin (2 milligrams) versus a placebo. Each participant was given combinations of vitamin C, vitamin E, beta carotene, and zinc. The study concluded that oral supplementation with long-chain polyunsaturated fatty acids had no substantial effect on cognitive function among the elderly, statistically speaking.
For the physical activity study, researchers concluded that a two-year, moderately intense exercise program—in comparison with a health education program—didn’t result in cognitive function improvements amongst sedentary older adults at risk of mobility disability. The Lifestyle Interventions and Independence for Elders (LIFE) study involved 1,635 participants between the ages of 70 and 89. It encompassed a structured exercise program involving resistance training, flexibility exercises, and walking.
Study authors Dr. Sudeep Gill and Dr. Dallas Seitz conclude that lifestyle factors, such as diet and exercise, still have important roles in the prevention of cognitive decline, dementia, and daily living. The authors suggest that the lack of effect with the supplements could be because participants started taking them too late in the aging process: “The process of cognitive decline may occur over decades, thus a short-term supplementation given too late in the disease may not be effective.”
Sources for Today’s Article:
Chew E., et al., “Effect of omega-3 fatty acids, lutein/zeaxanthin, or other nutrient supplementation on cognitive function the AREDS2 randomized clinical trial,” JAMA, 2015, doi: 10.1001/jama.2015.9677.
MacGill, M., “Omega-3 supplements, physical activity fail to show effect against cognitive decline,” Medical News Today web site, August 26, 2015; http://www.medicalnewstoday.com/articles/298533.php.