According to a recent study, supplementation with the fatty acid docosahexaenoic acid (DHA) may not slow cognitive decline in patients with Alzheimer’s disease.
Fatty acids, particularly omega-3 fatty acids like DHA, are important for the growth and functional development of the brain in infants. Earlier evidence has suggested that fish oil, which contains DHA and eicosapentaenoic acid (EPA), may help prevent cognitive decline in older adults.
The study, funded by Martek Biosciences (the manufacturer of the DHA pills used in the study) and the National Institute on Aging, included 401 adults with mild-to-moderate Alzheimer’s disease. The participants were randomly assigned to receive either 2 grams of DHA or placebo daily for 18 months. A total of 295 people completed the trial.
Cognitive function was evaluated using the Alzheimer’s Disease Assessment Scale and Clinical Dementia Rating and was found to be similar between both groups. When the researchers reviewed MRI scans in a subset of patients, they found that DHA did not appear to affect the rate of brain atrophy.
Although no benefit was reported in this study, fish oil has been shown to have various other health benefits. For instance, fish oil is commonly taken to help prevent heart disease, and supplementation has been shown to help lower triglyceride levels and blood pressure, reduce mortality rates and abnormal heart rhythms and prevent strokes and atherosclerosis. However, high doses may have harmful effects, such as increased risk of bleeding.
For more information about omega-3 fatty acids, please visit Natural Standard’s Foods, Herbs & Supplements database.
1. Natural Standard: The Authority on Integrative Medicine.
2. Quinn JF, Raman R, Thomas RG, et al. Docosahexaenoic acid supplementation and cognitive decline in Alzheimer disease: a randomized trial. JAMA. 2010 Nov 3;304(17):1903-11. View Abstract