Must Vegans Supplement Omega-3 Intake?The following information is from
Nutrition Answers from Virginia Messina, MPH RDDo vegans need to take supplements of omega-3 fatty acids? I've read that these fats are necessary for health, and that vegan diets are lacking in them.This question has come up a number of times on VegRD. The answer is extremely complex, mostly because we really don't know the answer. In fact, it is possible to make some recommendations but they are imperfect ones. First, a little background on omega-3s. The fats in question are long chain omega-3 fatty acids called DHA and EPA (these are abbreviations for docosahexanoic acid and eicosapentanoic acid). These fats are believed to be important for brain development, eyesight, and maybe for reproduction. They are also linked to reduced risk for heart disease, and perhaps other chronic diseases. The only good dietary sources of long chain omega-3s are fish, some eggs, and some sea vegetables. People who eat fish have high intakes. Lacto-ovo vegetarians may get some amounts from eggs. Vegans do not consume any long chain omega-3s.
However, this doesn’t mean that vegans don’t have these fats in their bodies. They do. These fats can be made from another omega-3 fat called alpha-linolenic acid (ALA). Vegans do eat ALA. The problem is that some vegans, especially those who avoid all fatty foods, may not eat enough ALA. It is found in significant quantities only in a few foods, namely flax seed or flax oil, soybean oil, canola oil, English walnuts, and to a far lesser extent in leafy green veggies. In addition, some dietary factors may interfere with the conversion of ALA to the long chain omega-3s. Trans-fatty acids (the fats found in margarines and many processed foods) may interfere with this conversion, although there is actually very little evidence for this relationship one way or the other. Also, the amount of another fat called linoleic acid (LA) can interfere with the conversion.
LA is actually an essential fat, so we need some in our diet, but needs are quite small and are very easily met. There is little danger of deficiency of this fat, but too much of it can cause problems. Therefore, there is an important balancing act here. It’s important to avoid high intakes of LA and to get enough ALA. The ratio of these two fats in the diet, as well as the total amount of fat seems to be important. The ideal ratio isn’t known, but for vegans who have no long chain omega-3s in their diets, it seems wise to aim for a very low ratio of LA to ALA — perhaps as low as 2:1. It’s difficult to suggest guidelines for achieving that exact ratio, however. The best that people can do is to make sure that they include a good source of ALA in their diet daily and limit sources of LA.
Should vegans take a supplement of long chain omega-3s to be on the safe side? Again, the answer isn’t clear. Vegetarians do have lower levels of DHA and EPA in their blood. We don’t know whether they are at a health disadvantage because of this. We also don’t know if this would change if more vegetarians paid attention to their intakes of ALA and LA. But research does suggest that ALA may not have the exact same effects in the body as the long chain omega-3 fats.
There is currently a supplement of DHA available for vegetarians; it comes from algae rather than fish, but it is encased in a gelatin capsule and therefore not vegetarian. There may be an advantage to using such a supplement, but an ethical concern against which to weigh this. So that’s the long answer to this question. The short answer is that we don’t yet know the answers about omega-3 fats in vegan diets.Update: Vegan DHA is now on the market and can be ordered from a number of web sites, including
VeganEssentials.com.
For now, the best advice is this:
* Include a good source of alpha-linolenic acid in your diet every day. Good sources include ground flax seed (and it must be ground), walnuts, hemp seed products (such as veggie burgers or cheese made from hemp), canola oil or soybean oil, sea vegetables or generous quantities of leafy green vegetables.
* Also, reduce the use of vegetable oils that are high in linoleic acid. These include sunflower, safflower, corn and sesame oils. Instead of these, use more soybean and canola oil, which are good sources of ALA, and also olive oil. Even though olive oil is not high in ALA, it is low in LA and it is a good source of monounsaturated fats.
* Limit consumption of foods that are rich in trans-fatty acids such as margarine, vegetable shortening, and processed foods.
* Keep total intake of fat moderate
