What is the preferred ratio of DHA/EPA in supplements?
The vast majority of studies which have evaluated and supported the benefits of consuming omega-3 fatty acid as DHA/EPA in fish or as supplements for cardiovascular events and related mortality have used mixtures of these two omega-3 fatty acids. All fish contain a mixture of both omega-3 fatty acids (DHA + EPA) and most studies using supplements (particularly the long-term studies) have used mixtures of these two fatty acids. In the more recent JELLIS study from Japan (see recent reports on our website) utilized a concentrate of EPA only. Since mixtures of DHA/EPA have been used in the vast majority of long-term studies related to cardiovascular events and mortality, the 1999 Workshop in Bethesda, Maryland (invited international experts) recommended an intake of 650 mg of omega-3 fatty acid in the form of DHA/EPA combined each day for normal healthy people with at least one-third of the mixture being represented by either EPA or DHA. In other words, a recommended DHA: EPA ratio ranging from 2:1 on one extreme all the way to 1:2 on the other. Long-term studies over many years which look at cardiovascular disease and related events (including mortality) would be ideal wherein various mixtures DHA+EPA were studied and compared to purified concentrates of EPA or purified concentrates of DHA. Due to prohibitory costs, it is unlikely that such studies will be initiated for many years to come. It should be noted that the focus has been on DHA in infant formula preparations in view of the fact that DHA accumulation in the brain and retina (eye) of young infants has been directly implicated with respect to a structure-function relationship for DHA in optimal neuronal and visual functioning, respectively.