The Truth About Fish Oil Supplements: What the Latest Research Says

Fish oil supplements are popular among those hoping to boost heart health, but do they really work? 

Marine-based omega-3 fatty acids (DHA and EPA), the key ingredient in these capsules, are widely believed to protect against heart disease, the leading cause of death worldwide. However, recent research shows this is a bit more complicated than once thought.

The Mixed Results of Fish Oil Studies

The debate around fish oil supplements largely stems from mixed clinical trial results and their conclusions. While some studies indicate heart-protective benefits, others suggest that the effects may not be as clear-cut. 

For instance, a major clinical trial, VITAL, which followed nearly 26,000 middle-aged and older adults over five years found that taking 1 gram of fish oil supplements daily did not significantly lower the overall risk of major cardiovascular events or dying from heart disease across the study population as a whole. The researchers concluded that fish oil supplementation as a general health-promoting strategy has no role.

One twist was that the VITAL study also found several groups that appeared to benefit from taking fish oil supplements. These included individuals with low baseline fish consumption, those with multiple risk factors for heart disease, and African Americans. Among these subgroups, adding fish oil supplements resulted in significant reductions in heart attack rates, with African American participants showing the most dramatic improvement. As another twist, these same groups did not seem to benefit in terms of stroke risk, adding an additional layer of complexity to the conversation.

Another trial, called REDUCE-IT, looked at a high-dose prescription form of EPA omega-3 called icosapent ethyl in people who were already at high risk due to conditions like diabetes or prior cardiovascular disease. This trial found that daily use of 4 grams of this medication significantly lowered the risk of major cardiovascular events. The results of this trial have led to FDA approval of icosapent ethyl (Vascepa®) for use in select high-risk individuals.

But the REDUCE-IT trial had its own twists. Turns out the placebo arm of the trial used caplets full of mineral oil, to mimic the look and consistency of the omega-3 supplement tablets. Mineral oil is pro-inflammatory and it’s possible that the “reduction” in events seen in the icosapent ethyl group wasn’t a decrease at all.  Rather what we were observing was an INCREASE in event rates caused by mineral oil consumption. 

The debate rages on.

Fish Oil Supplements vs. Omega-3-Rich Foods

An important fact to keep in mind is that we can get all the  EPA and DHA we need from food and that this may be more beneficial for heart health than getting these nutrients from supplements. Fatty fish like salmon, mackerel, and sardines are rich in these types of omega-3s, along with other nutrients that could enhance their cardiovascular benefits. Fish not only provide omega-3s but also avoid some of the potential risks associated with fish oil capsules, such as concentrated heavy metal content or oxidation of the oil, which could potentially increase artery blockages.

The risks of fish oil supplements, especially when taken in high doses, include an increased likelihood of atrial fibrillation (an irregular heart rhythm that can lead to stroke) and bleeding issues. Therefore, experts agree that it's generally best to obtain DHA and EPA omega-3s through diet whenever possible, as the increased risk of atrial fibrillation and bleeding are generally not seen in this context.  

Finally, it’s important to point out that there is a plant-based form of omega-3 called ALA and that this is an ESSENTIAL fatty acid as we cannot manufacture it inside our bodies. While we can make DHA and EPA from ALA, the reverse does not hold true.  Therefore, it’s not enough to just eat fish.  You also need to make sure you are including flax, chia, walnuts and other healthful sources of ALA in your diet.  Step One Foods to the rescue!

Who Can Benefit from Omega-3 Supplements?

The story of fish oil supplements is still unfolding, and ongoing research will continue to shed light on their role in heart disease prevention. If you fall into a high-risk category or consume little to no fish, fish oil supplementation might offer some heart health benefits—but it's always wise to discuss your supplement regimen with your healthcare provider.  And don’t go overboard.  Fish oil may be “natural” and “only a supplement” but every compound we put into our bodies will have a biological effect.  

For most people, focusing on a heart-healthy diet that includes omega-3-rich foods is a safer bet. Fatty fish, flaxseeds, walnuts, and chia seeds are excellent options that, in combination, not only provide the full range of omega-3s but also promote overall health. One truth repeatedly proven is that supplements may help fill a nutrition gap, but they are no replacement for a well-rounded diet.