n-3 Fatty Acids: Food or Supplements?

In summary, for all fatty acids, a food-based approach is recommended. For individuals who do not eat fish, other options can be pursued, such as "designer" foods high in these long-chain n-3 fatty acids, foods fortified with these fatty acids, or even supplements (29,50). DHA-rich algal supplements are an alternative source of DHA vs fish or fish oil, especially for vegans, and as Hoffman and colleagues (34) have shown, are equivalent with respect to bioavailability. This is one criterion that should be assessed for supplements per guidance given in the ADA position paper on fortification and nutritional supplements (1). Although it would seem that because bioavailability is similar between DHA supplements and food sources of DHA, functionality also would be comparable, but this needs to be evaluated. Another important consideration relates to nutrient (ie, fatty acid) balance. Specifically, high doses of DHA have been shown to inhibit elongases and desaturases, which in turn affect the metabolism of other n-3 and n-6 fatty acids. Important questions remain about the optimal amount of DHA that should be recommended and, notably, how DHA affects the metabolism of C18 and longer n-6 and n-3 fatty acids, and whether this might result in any adverse health outcomes. Based on the available evidence, a DHA supplement provided in the appropriate dose (for which there currently are no recommendations) would be expected to confer health benefits, especially in individuals who do not eat fish. The expertise of registered dietitians is needed to communicate sound nutrition information about fatty acid recommendations, and to help people achieve these through a food-based approach or via supplements, if warranted. However, in the absence of specific recommendations for EPA and DHA individually at the present time, this is challenging. Thus, in the meantime, registered dietitians should play a key role in assuring that individuals do not overconsume DHA from algal supplements.