BOSTON, MASSACHUSETTS. Cognitive decline and dementia are common among the elderly. It is estimated that 10% of people aged 65 years and 33% of individuals aged 85 years suffer from cognitive impairment, more specifically, a reduced ability to learn and remember. There is considerable evidence that both DHA (docosahexaenoic acid), a major component of fish oil supplements, and lutein, a common dietary carotenoid, are essential for brain health. There is also evidence that lutein tends to accumulate in the macula (a small area of the retina essential for clear, detailed vision) and thereby helps prevent the initiation and progression of age-related macular degeneration. Now researchers at the Center on Aging at Tufts University report that supplementing with DHA and lutein is effective in preventing cognitive decline.
Their double-blind clinical trial involved 49 women (aged 60 to 80 years) who were randomized to receive DHA (800 mg/day), lutein (12 mg/day), DHA and lutein, or placebo. The study participants had blood samples drawn at enrollment and were subjected to a battery of cognitive tests (verbal fluency, memory, processing speed, and accuracy) at enrollment and after 4 months of supplementation. Diet was monitored with food frequency questionnaires at enrolment and at 2 and 4 months to ensure that there were no confounding changes in dietary intake. All cognitive outcomes were also adjusted for age and level of education.
At the end of the study, the researchers observed that participants who had taken DHA and lutein scored significantly higher on tests involving different aspects of memory. Thus, the DHA and lutein group improved in efficiency, learning shopping lists or lists of words with fewer trials, on average, after supplementation. All three supplement groups improved significantly on the verbal fluency test. It was also noted that DHA supplementation (found in fish oil supplements) resulted in an increased uptake of lutein by the macula. The researchers conclude that supplementation with DHA and lutein significantly improves cognitive function in the elderly. Other studies have also found that DHA, one of the main components in fish oil supplements, helps prevent Alzheimer’s disease.
Johnson, EJ, et al. Cognitive findings of an exploratory trial of docosahexaenoic acid and lutein supplementation in older women. Nutritional Neuroscience, Vol. 11, No. 2, 2008, pp. 75-83