Omega-3 Supplementation: Not For Everyone
William Harris, MD, a vegan of 40 years, recently told me about his experiences with taking omega-3s, both ALA and DHA. He said that after taking ALA by way of ground up flaxseeds, 1-2 tsp per day for about 5 years, he started to bruise very easily, and on one occasion in December 2000 the bursa over his left knee spontaneously filled with blood without any previous injury. Thinking this might be due to excess synthesis of EPA from the ALA in the flax, he searched the literature and was able to find one supporting reference from a plastic surgeon, who was advising his face lift patients to stop the flax seed prior to facial surgery.
Harris decided to stop taking flax seeds and the easy bruising went away after 4 weeks. Four years later, after reading about DHA shortage in vegans, he started taking DHA supplements. After taking them for only 4 weeks, the bruising returned. He stopped taking the DHA and the bruising, once again, ceased.
It might be that Dr. Harris is an anomaly, but if anyone finds that they are having easy bruising, it might be best to stop taking or drastically cut back on any omega-3 supplementation.
A talk Dr. Harris gave to the Hawaiian Vegetarian Society last year, in which he goes into more detail about his thoughts on omega-3s, can be found here. The omega-3 discussion starts at 32:00.
In the video, Dr. Harris says that I think vegans need to take DHA. I am not so sure that vegans need to take DHA – the research is far from conclusive. But I would say that it is prudent (assuming they have no reason to think they are getting too much omega-3, as Dr. Harris was). Also note that Dr. Harris eats a very unprocessed diet, low in omega-6′s compared to the average vegan, and that could explain why he converts ALA into EPA more efficiently than your average vegan.
You can read more on omega-3′s in the vegan diet in Omega-3 Fatty Acid Recommendations for Vegetarians.