Considering all the supplements that most of us take, we have surprisingly little evidence that the overwhelming majority of them do anything for us. The two biggest exceptions are vitamin D and omega-3 oil, which I have written about here.
Even with these well-tested supplements, the experts have little advice to give us. Now, however, a team of scientists from the University of Lyon in France just reported on how much of one type of omega-3 oil to take so that we can prevent heart attacks and strokes, the major complication of diabetes. This is the first study to identify how much omega-3 oil we need to promote optimal heart health.
They studied DHA or docosahexaenoic acid, which some studies suggest have more potent and beneficial effects than the other omega-3 oil that we usually take, EPA or eicosapentaenoic acid, according to their research communication in September issue of The FASEB Journal, which the Federation of American Societies for Experimental Biology publishes.
Only the abstract of the study is online. But one of the study's authors, Evelyne Véricel, was kind enough to send me the full text.
Dr. Véricel and colleagues examined the effects of increasing doses of DHA on 12 healthy male volunteers between ages of 53 and 65. These men took 200, 400, 800, and 1600 mg of DHA -- and no EPA -- each day for two weeks for each dose amount. The researchers examined the blood and urine samples of the volunteers for biochemical markers indicating the effects of each dose.
"Only 200 mg per day of DHA for two weeks induced an antioxidant effect," they write. Taking 400 to 800 mg per day reduced the platelet function of these healthy men. Moreover, they concluded, taking 1 gram (1,000 mg) was less active against platelet activation and was "rather deleterious on redox status."
I'm surprised at how little DHA the study indicated we need. I usually take krill oil for my omega-3 requirements because it is more bio-available. But sometimes I use the Carlson brand of fish oil and take three capsules per day. That gives me 600 mg of DHA as well as 900 mg of EPA and 300 mg of other omega-3 oils.
This is just one small study. But it does indicate that we don't need that much and in fact may be better off with less omega-3 oil.