Nutritionists have long endorsed fish as part of a heart-healthy diet, and recent studies have suggested that omega-3 fatty acids found in the oil of certain fish, algae and human breast milk may also benefit the brain by lowering the risk of Alzheimer's disease. In order to test whether an omega-3 fatty acid called docosahexaenoic acid (DHA) can impact the progression of Alzheimer's disease, researchers across America are evaluating DHA in a clinical trial, the gold standard for medical research.
The study is supported by the National Institute on Aging (NIA) of the National Institutes of Health. A nationwide consortium of leading Alzheimer's disease researchers is supported by NIA and coordinated by the Alzheimer's Disease Cooperative Study at the University of California, San Diego. The clinical trial is taking place at 52 sites across the U.S. The study is seeking 400 participants ages 50 and older with mild to moderate Alzheimer's disease. Researchers primarily will evaluate whether taking DHA over many months slows the progression of both cognitive and functional decline in people with mild to moderate Alzheimer's. During the 18-month clinical trial, investigators will measure the progress of the disease using standard tests for functional and cognitive change.
James Lah, MD, associate professor of neurology at Emory, will lead Emory's participation. Oregon Health and Science University's Joseph Quinn, MD, associate professor of neurology, is directing the national study.
"Evidence to date in various research studies that have examined the effect of omega-3 fatty acids on Alzheimer's disease merits further evaluation in a rigorous clinical trial," says Dr. Lah. "Our hope is that we may find out that DHA plays a role in slowing the progression of this destructive disease."
In recent U.S. and European studies, scientists reported that people with the highest blood levels of DHA were about half as likely to develop dementia as those with lower levels.
"Study volunteers will be critical to helping us find out if DHA can make an impact on the disease process," says Dr. Lah. For the clinical trial, the Martek Biosciences Corporation of Columbia, Md., will donate a pure form of DHA made from algae devoid of fish-related contaminants.
Participants will receive either two grams of DHA per day or an inactive placebo pill. About 60 percent of participants will receive DHA, and 40 percent will get the placebo. Doctors and nurses at the 52 research clinic sites will monitor the participants in regular visits throughout the trial. To ensure unbiased results, neither the researchers conducting the trial nor the participants will know who is getting DHA and who is receiving the placebo. In addition to monitoring disease progression through cognitive tests, researchers will also evaluate whether taking DHA supplements has a positive effect on physical and biological markers of Alzheimer's, such as brain atrophy and proteins in blood and spinal fluid.
More information
For more information about the study, contact the NIA's Alzheimer's Disease Education and Referral Center at 1-800-438-4380, or by email to adear@nia.nih.gov , or visit the referral center's Web site. SOURCES: Emory University’s Woodruff Health Medical Center Press Release, June 25
