Do Omega-3s Work?

Healthy Aging

Why omega-3 science is so messy

Last week, we shared the science behind omega-3 supplements’ ongoing quality issues, including how more than 50% have lipid peroxidation levels exceeding international voluntary safety standards. We also covered the National Institutes of Health’s summary that omega-3 fish oil supplements don’t reduce the risk of heart disease.

This week, we are helping to answer the question:

Wait. If omega-3 supplements don’t work, what about all that science supporting omega-3 benefits?

Great question! There are four reasons why there has been a mismatch between omega-3 science and omega-3 supplements:

• First, eating fish is beneficial. As summarized by Chen et al., many studies support that fish, as part of a healthy eating pattern, can offer long-term health benefits, including better heart health. This is why the NIH recommends eating 2 to 3 servings of fish per week.
• Second, associations between higher omega-3 blood levels and better health may reflect the benefits of eating a diet with more fish. Studies have repeatedly shown that people with higher omega-3 blood levels have better long-term health. Because people who eat more fish have higher omega-3 levels, omega-3s may just be a biomarker of better health from eating fish.
• Third, omega-3 supplements are less likely to work if levels are too low and they are oxidized. While omega-3s may provide benefits when provided at sufficient levels, Kleiner et al. showed most omega-3 supplements contain less EPA and DHA than what is listed on the bottle. Further, Mason et al. showed that oxidized omega-3 in supplements lose the ability to exert a key heart-protective effect.
• Fourth, prescription-strength purified EPA (without DHA) does appear to have health benefits. As described by Sherratt et al., extensive randomized, placebo-controlled clinical trials show that a prescription form of the purest EPA formulation, which excludes DHA, reduces the risk of death from heart disease. The quality of this form of EPA, however, is highly controlled and very different from fish oil supplements.

In summary, omega-3 science has been inherently complicated by different sources (like that fish you had for dinner vs. fish oil in a bottle) with different purity, different concentrations, and different levels of quality. This is likely why for every positive study on omega-3s, there seems to be another one that disputes it. There have been, however, two consistent findings:

• First, eating fish 2 to 3 times a week is good for your health.
• Second, purified prescription EPA can be helpful, too.