Hi {{first name | there}},

I used to avoid omega-3 supplements for a highly technical reason: they were hard to swallow 😅.

Then my LDL reached 192 mg/dL, my ApoB was 128 mg/dL, and I started weighing every possible intervention for heart disease prevention much more carefully. Fish oil had enough evidence behind it that I took it seriously.

What I found changed what I take and why, not to mention how I advise my longevity patients.

Below is a rundown of the omega-3 evidence so you can see if it's all hype.

For plasma EPA+DHA, the report prints both a reference range and an "optimal" cutoff. Those are not the same thing.

My first EPA+DHA result was 3.0%. As a bit of an overachiever, I saw that it sat just below the report's "optimal" category and bought some high-dose capsules. I still hated swallowing them, so I eventually moved to liquid fish oil and usually took about 2 grams per day.

My later whole-blood tests reached as high as 11.2%, so I was certainly successful in raising my omega-3 exposure. Whether I improved my health was the real question.

Over the years, I did manage to improve my heart numbers dramatically, but ultimately it had little to do with my fish oil supplements.

Repatha plus ezetimibe moved my LDL from 192 to as low as 37 mg/dL and my ApoB from 128 to 45 mg/dL. Those drugs reduce the ApoB-containing particles that drive atherosclerosis. Fish oil changed my fatty-acid numbers to unclear benefit.

If you want the heart side of this story, I explain why a standard lipid panel can miss risk and how I use statins, ezetimibe, and PCSK9 inhibitors.

I, and the rest of the longevity universe, have bought into omega-3 because the biology makes sense.

In the 1970s, researchers found more EPA in the platelet lipids of Greenland Inuit. They proposed that EPA made platelets less likely to clump. (The reports of unusually low heart-disease rates that inspired this work have since been disputed.)

A small 1984 human study found that an EPA/DHA-rich diet sharply reduced the liver's production of VLDL, which carries much of the triglyceride in our blood. Subsequent research confirms that prescription-dose EPA or EPA+DHA can lower high triglyceride levels by roughly 20% to 30%, and often more when the baseline starts very high.

Post-heart-attack studies have also suggested fewer sudden deaths associated with fish consumption. Because EPA and DHA affect cell membranes and cardiac ion channels, researchers thought they might prevent dangerous heart rhythms. Later, researchers identified EPA- and DHA-derived resolvins and other molecules that help end an inflammatory response.

But does this mean everyone should be on fish oil (or vegan alternatives)?

The four main omega-3 fats differ too. We have to get ALA from food, but we convert only a small amount into EPA and DHA. EPA plays a larger role in signaling and liver triglyceride handling. DHA is a structural fat in brain and retinal membranes. DPA is less studied, but is thought to act partly as a reservoir.

In a related field, we have seen this logic behind omega-3s (specifically DHA) fail in eye care. DHA is concentrated in the retina, yet adding EPA and DHA to the AREDS formula did not prevent progression to advanced macular degeneration in AREDS2.

A salmon dinner gives you EPA and DHA, protein, and other nutrients. It also replaces another meal. If you eat salmon instead of processed meat or a burger and fries, that swap may matter as much as the omega-3 itself.

A capsule replaces nothing, and its label can be misleading. A bottle that says "1,000 mg fish oil" may contain only about 300 mg of EPA plus DHA. The rest is other fat.

Prescription icosapent ethyl is a third category: purified EPA at 4 grams per day. It is a regulated drug prescribed for specific situations.

VITAL came closest to how most people use fish oil: one standard capsule a day, taken just in case for general wellness. The trial included 25,871 generally healthy adults. The result showed that one gram of marine omega-3 per day did not significantly reduce the main cardiovascular endpoint. A secondary analysis found fewer heart attacks, but the trial overall did not show that routine fish oil prevents cardiovascular disease.

Common criticisms suggest VITAL simply used too little. STRENGTH tested 4 grams per day of an EPA+DHA product in 13,078 high-risk adults who were already taking statins.

In this trial, the biomarkers changed. The cardiovascular events still did not, and researchers stopped the trial early for futility.

In addition, new-onset atrial fibrillation occurred in 2.2% of the omega-3 group and 1.3% of the corn-oil group.

Then some good news! REDUCE-IT did find a benefit. It studied statin-treated patients with elevated triglycerides who already had cardiovascular disease or had diabetes plus other risk factors. They received 4 grams per day of prescription icosapent ethyl or placebo, and the primary events were defined as either cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or unstable angina.

Over a median of 4.9 years, the primary event rate fell from 22.0% to 17.2%. That is a 4.8-point absolute reduction, or a number needed to treat of about 21 in this high-risk population.

Hospitalization for atrial fibrillation or flutter rose from 2.1% to 3.1%. Serious bleeding was 2.7% versus 2.1%, a difference that did not meet statistical significance.

Translation: a specific prescription form of EPA-only at 4g daily helped certain high-risk patients. That does not mean a typical over-the-counter fish-oil supplement will provide the same benefit.

Why did REDUCE-IT and STRENGTH disagree? We'll never know for sure, but the products and patients differed, as did the blood levels they reached. REDUCE-IT also used mineral oil as its placebo, and researchers still debate whether that made the benefit look larger (if mineral oil led to worse outcomes).

Now there is some data that shows that perhaps omega-3 supplementation is not completely harmless.

A 2026 meta-analysis pooled 35 trials and 114,592 people. Among patients at high cardiovascular risk who took more than 1,500 mg per day of EPA/DHA, the odds of AF were 43% higher. The absolute increase was 0.8%. Other dose-and-risk groups did not show a statistically significant increase.

43% sounds high, but that is an absolute increase under 1%. That may be a reasonable trade for a high-risk patient receiving the benefit seen in REDUCE-IT. It looks different for someone who isn't high risk for heart disease, however, especially if they're taking a random dose of 2 or 3 grams fish oil daily for "brain, heart, inflammation, and longevity."

I still eat fish. I don't push as hard on high-dose omega-3 supplementation for general longevity.

What I do now:

Prescription omega-3 can lower very high fasting triglycerides. Icosapent ethyl may also make sense for someone who closely resembles the REDUCE-IT population, after weighing AF, bleeding, cost, and pill burden.

If someone eats no seafood, a modest fish- or algae-derived supplement can fill a dietary gap. I would call that nutrition, not proven cardiovascular prevention.

For a generally healthy adult who eats fish and has normal triglycerides, I have a hard time naming the benefit of high-dose OTC fish oil. "Brain, heart, inflammation, and longevity" is not a specific enough treatment goal.

Has this changed your practice around omega-3 supplementation?

Hillary Lin, MD

Disclosure: I have an affiliate relationship with Seatopia and may earn a commission at no added cost to you. Use my referral link and enter HILLARYLINMD for $20 off your first order.

The Modern Lipid Playbook Part 2: Why Your Lipid Panel Isn't Enough

Fish oil brought me back to a basic question: are we changing a lab result, or lowering risk? In this episode, I explain why a standard lipid panel can miss risk and how ApoB, Lp(a), CAC, and CCTA change the next decision.

Watch on YouTube | Subscribe to The Longevity Show

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