A team of French scientists have found the dose of DHA (docosahexaenoic acid) that is “just right” for preventing cardiovascular disease in healthy men. In a research report appearing in the September 2009 print issue of The FASEB Journal (FASEB J. 2009 23: 2909-2916), the scientists show that a 200 mg dose of the omega-3 fatty acid DHA per day is enough to affect biochemical markers that reliably predict cardiovascular problems, such as those related to aging, atherosclerosis, and diabetes. This study is the first to identify how much DHA is necessary to promote optimal heart health.

“This study shows that regularly consuming small amounts of DHA is likely to improve the health status of people, especially in regards to cardiovascular function,” said Michel Lagarde, co-author of the study.

To determine the optimal dose of the omega-3 DHA, Lagarde and colleagues examined the effects of increasing doses of DHA on 12 healthy male volunteers between ages of 53 and 65. These men consumed doses of DHA at 200, 400, 800, and 1600 mg per day for two weeks for each dose amount, with DHA being the only omega-3 fatty acid in their diet. Blood and urine samples were collected before and after each dose and at eight weeks after DHA supplementation stopped. The researchers then examined these samples for biochemical markers indicating the effects of each dose on the volunteers. An important biochemical marker of oxidative stress in the body - urinary isoprostane - was significantly lower after 200 mg per day of DHA but was increased after 1600 mg per day. Thus, supplementation with only 200 mg per day of DHA for 2 weeks induced an antioxidant effect in the body.

“Now that we have a very good idea about how much DHA is just right, the next step is to try it out in an expanded clinical trial that involves many more people,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. “Until then, I’ll stick with tasty foods that contain DHA, like fish, rather than getting a quick fatty-acid fix at the local vitamin store” (Courtesy of EurekAlert!, a service of AAAS).

The abstract of this omega-3 fatty acid study is available free here:

Long-chain omega-3 docosahexaenoic acid: dose effect of DHA intake on oxidative damage in healthy men