Omega 3 indices: almost equal situation between vegetarians and vegans

The levels of Omega 3 found in fish consumers, vegetarians and vegans are similar to each other. This was revealed in a study coordinated by the University of East Anglia (Norwich, UK), in which Alisa Welch and colleagues investigated the hypothesis that excluding fish from one's diet corresponded to reducing the presence of these valuable molecules in the body. The results of the research were published in the American Journal of Clinical Nutrition.

Sources of Omega-3

Omega-3 fatty acids are found in a variety of animal and plant foods, but the main source of these nutrients is fatty fish. Fish contain high levels of both EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the active Omega-3s within the body. Plant-based foods (such as walnuts and flaxseeds), on the other hand, are a better source of ALA (alpha-linolenic acid). The latter is a precursor of EPA and DHA. Once introduced through the diet, the body must convert it to these 2 fatty acids in order to benefit from the action of Omega-3. For this reason, Welch and colleagues decided to analyze whether choosing to ban fish from one's diet (as those who are vegetarian or vegan do) could reduce the presence of EPA and DHA in the body.

The study

The research involved 14,422 individuals belonging to the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study group. The authors analyzed data on participants' dietary habits, collected through a weekly diary, toanalyze the existence of any correlation between dietary regimen and levels of Omega-3 present in the bloodstream. In addition, the concentrations of EPA and DHA in blood plasma were measured. With this information, the conversion rate of ALA into the other 2 Omega-3s could also be calculated.

The results

Analyses have shown that for those who do not eat fish but include other animal foods in their diet, the main source of Omega-3s is meat. Vegetarians, on the other hand, obtain these nutrients from spreadable fats (e.g., butter or margarine), soups, and sauces. The total amount of Omega-3 introduced by those who do not eat fish was found to vary between 57 and 80 percent of that typical of those who do. However, the differences observed in plasma concentrations were significantly smaller. Not only that, the conversion rate of ALA to EPA and DHA was found to be higher in those who do not eat fish and in women.

An unexpected conversion rate

Based on these results, the researchers concluded that diet does not strongly influence the levels of Omega-3 present in the body. The authors' hypothesis is that this is made possible by the fact that in those who do not eat fish, the conversion rate of ALA to EPA and DHA is higher than in those who do.