High Dose Fish Oil NOT Effective in Promoting Weight Loss on a Professionally Monitored Weight Loss Regimen

Those of you who visit the SuppVersity pretty regularly will have noticed that I am reluctant to buy into all the hype about omega-3 fatty acids and the myriad of purported health benefits of high dose fish oil supplementation. According to the results of a very recent study published in the Journal of the American Society for Nutrition (DeFina. 2010) my doubts appear to be legitimate.

Table 1: Mean change in adiposity measures in the omega-3 supplement and placebo groups

The scientist investigated the effect of 3.0 g eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) at a 5:1 ratio (EPA:DHA) [standard fish oil caps usually have a ratio of 3:2 and you would have to take about 10 caps to get to that amount of EPA + DHA combined] on the weight loss of 128 obese and overweight individuals. Although fish oil treated individuals tended to lose a few more grams of body fat (cf. Table 1), this effect was no statistically significant, so that the researchers consequentially conclude:

No significant weight-reduction benefit was seen with the addition of omega-3 fatty acid supplementation in this weightloss study with lifestyle intervention. Overall, the participants in both arms lost .5% of their body weight, which was considered clinically significant in prior trials of diet, exercise, or medication.

A final word, before you throw away your fish oil supplies: There is one thing, which to my mind could have changed the outcome of the study considerably and that would be the use of a standard or even better a high DHA fish oil preparation. I've been following this discussion for quite some time now and whenever there were negative effects associated with fish oil supplementation, i.e. blocking the immune system, downregulation of the HPTA, etc. these were related to the highly anti-inflammatory EPA content of the oils. So, if you insist on taking your fish oil. Look for a brand that has a low EPA:DHA ratio and do not forget that for hard training athletes on low carb diets the "bad" saturated fats are "essential", as well.