The Council for Responsible Nutrition (CRN) reminds consumers that docosahexaenoic acid (DHA), found in fatty fish and several types of dietary supplements, plays a critical role in cognitive function and heart health. A recent study published in the November 3 issue of the Journal of the American Medical Association (JAMA) does not diminish the important benefits of DHA. CRN believes more research should be conducted with respect to DHA's role in reducing the risk of Alzheimers disease and dementia.
"The concern with this study is that it focused on supplementing DHA in individuals who were currently coping with Alzheimers disease. It didn't answer the question of whether DHA taken over long periods of time and several years prior to disease onset could have helped prevent these participants from developing the disease," said Duffy MacKay, N.D., vice president, scientific and regulatory affairs, CRN. "Further, the study only tested DHA under the assumption that it could be used as a treatment, which is highly unlikely given how little we know about Alzheimers disease. There is still much to be learned about the potential of DHAand all omega-3 fatty acidsand the many health benefits they offer consumers."
Results from the study are in conflict with results from previous studies, which have suggested that DHA supplementation for longer periods of time often in conjunction with eicosapentaenoic acid (EPA) supplementation and prior to the onset of cognitive decline might help reduce the risk of dementia and Alzheimers disease. Previous studies on the benefits of DHA have also demonstrated its importance in providing essential building blocks for brain tissue, helping maintain normal metabolism and eicosanoid production, and supporting heart and eye health.
The trial Docosahexaenoic Acid Supplementation and Cognitive Decline in Alzheimer Disease sought to determine if DHA supplementation could slow the rate of decline in patients with dementia or Alzheimers disease. Cognitive function was measured upon entering the study, and again at six months, 12 months and 18 months. During the course of the study, participants were given either 2g of DHA per day, or a placebo. Some 295 individuals completed the double-blind, multi-center, randomized controlled trial, and all previously consumed less than 200mg of DHA per day.
The study employed algal oil, which provides DHA without EPA. There are several sources of omega-3 fatty acids, such as krill oil and fish oilboth of which also contain EPA and, if used in this study, may have yielded different outcomes.
"Whether through diet or through the use of dietary supplements, individuals should ensure they are receiving adequate amounts of DHA and EPA, and they shouldnt wait until they begin to experience symptoms of a health concern," said MacKay. "Should consumers choose to get the recommended amounts of DHA through dietary supplements, they should also remember that supplements are not a cure or treatment for any disease, but when incorporated into a healthy lifestyle, they can play an important role in maintaining overall health and wellness."
From the November 15, 2010, Prepared Foods E-dition