Your Guide to Omega-3s

They help maintain proper cellular function and communication and can help reduce inflammation, which is a hallmark of all chronic diseases. There are three main types of omega-3s:

• ALA (alpha-linolenic acid, found in plants)
• EPA (eicosapentaenoic acid, primarily found in fish)
• DHA (docosahexaenoic acid, primarily found in fish)

Heart health:

• Omega-3s can help reduce the risk of cardiovascular disease by increasing HDL.
• High doses of omega-3s have been shown to reduce triglycerides in the blood; high levels of triglycerides can lead to atherosclerosis and therefore increase the risk of heart disease and stroke.
• Omega-3s, whether consumed in your diet or via supplements, have been shown to lower blood pressure in people with hypertension.

Brain health:

• Omega-3s are thought to be crucial for brain health and there is some early evidence that they have the potential to reduce the risk of age-related cognitive decline.
• Studies have found people with a higher omega-3 index to have larger hippocampal volumes and stronger abstract reasoning.
  • The mechanism for this benefit hasn’t been firmly determined yet. Scientists hypothesize the benefit might be conferred from DHA and EPA’s anti-inflammatory properties, or because fatty acids are needed in neuron membranes.
• Omega-3s can help with dementia-prevention in those who are genetically predisposed to Alzheimer’s:
  • “If someone out there has two copies of APOE4,”—the variant that is associated with an increased risk of Alzheimer’s—“I want them to eat so much fish they have gills,” says Dr. Richard Isaacson. “That's an over-exaggeration, but eating fatty fish twice a week often is not enough to get the levels of omega-3s up sufficiently in the blood.”

Other health benefits:

• Research shows that omega-3s are also helpful for eye health, mood regulation, joint health, and other inflammatory conditions.
• Omega-3s are critical for fetal development, so all pregnant people should consume higher amounts of omega-3s.

Some fish are an excellent source of omega-3s. Our doctors recommend wild, cold-water fatty fish. You can use the SMASH acronym to remember what’s high in omega-3s:

• Sardines
• Mackeral
• Anchovies
• Salmon
• Herring

Plant-based omega-3s can be found in high concentrations in:

• Flax seeds
• Chia seeds
• Walnuts
• Soybeans and tofu
• Canola oil
• Navy beans
• Brussels sprouts
• Avocados

While the body can convert some plant-based omega-3s (ALA) into marine omega-3s (EPA and DHA), those who don’t eat fish and have a low omega-3 index may want to supplement with a fish oil pill.

We recommend that anyone choosing to supplement with fish oil do so under the guidance of a physician, who should ideally follow their omega-3 levels by testing with panels such as OmegaQuant.

“The usual dose of omega-3s that I recommend personally, because I'm trying to balance safety and efficacy, is 2 grams of DHA and about 600 to 700 milligrams of EPA,” says Dr. Isaacson.

A 2024 paper in the British Medical Journal (BMJ) about omega-3s generated significant media attention. Given the widespread use of omega-3 supplements among health-conscious people, it’s important to take a closer look at the study, which had major limitations and problems.

The study, which looked at 400,000 participants from the U.K., found a slightly increased risk of atrial fibrillation and stroke among people who self-reported, via a digital survey, regular fish oil use. (Among those with known cardiovascular disease, there was a lower risk of progressing from atrial fibrillation to heart attack and a lower risk of death from heart failure.)

However, there were notable problems with the study. First, it was observational, so causal conclusions could not be drawn. Second, the study population was predominantly white, which may limit the generalizability of the findings. Third, the findings contrast with previous studies, such as the REDUCE-IT trial, which showed significant cardiovascular benefits from EPA supplementation. Finally, the study did not provide information on the dose or formulation taken by the participants.

Dr. Robert Rountree, an integrative medicine expert and fellow of the Atria Academy of Science & Medicine, cites another limitation of the study. “No measurements of omega-3 fatty acids were ever done, so we don’t even know whether the individuals were taking enough to impact their blood levels.”

Given the large body of research about the benefits of omega-3s, our experts feel it is appropriate for those who are supplementing to continue to do so—particularly those at risk for heart disease, cognitive decline, or inflammatory disorders.