Fish Oil
Fish oil comes from the tissues of oily fish like salmon, mackerel, and sardines. It contains omega-3 fatty acids, called EPA and DHA, which are healthy fats the body can’t make on its own. These fats help support the heart, brain, and reduce inflammation. Taking fish oil as a supplement gives your body extra omega-3s to help keep it healthy.
Primary Benefit: Supports cardiovascular health (reducing heart attack risk) and cognitive function (reducing neurodegeneration).
Target Audience: Most relevant for those with omega-3 deficiency or the APOE4 genetic variant.
Key Caution: Acts as a blood thinner and carries a slight risk of atrial fibrillation.
Is this used to correct a deficiency or achieve supramaximal levels?
Deficiency
Is it taken for life span or health span?
Mostly healthspan and lifespan indirectly
Is it targeting a specific disease? Or general health?
Specific- cardiovascular and neurodegenerative disease
Any genetic involvement?
Possessing the APOE4 genetic variant has a higher risk for deficiency. May benefit from higher DHA levels (a type of omega 3)
Is there a biomarker to track its effects?
Omega-3 index Slow to change—takes ~3 months for new red blood cells to reflect dietary adjustments
MOA of supplement
Fish oil supports cardiovascular health through several mechanisms. It reduces very low-density lipoproteins (VLDL) and triglycerides by enhancing fatty acid oxidation in the liver. It also inhibits the NF-κB pathway, which plays a key role in inflammation, thereby reducing inflammatory responses. Additionally, fish oil promotes nitric oxide production, leading to vasodilation (widening of blood vessels), and acts as a mild antiplatelet agent by decreasing platelet aggregation, which reduces the risk of clot formation.
Risk vs reward
+May improve cardiovascular heath
+May support cognition and prevention of neurodegenerative diseases
- Slight increased risk of developing atrial fibrillation, a cardiac arrhythmia
- Acts as a blood thinner so may act as a blood thinner/ not appropriate for those on must be taken with caution when on blood thinning mediation
Evidence for it?
Systematic review and meta-analysis A meta-analysis of 149,051 participants found that omega-3 fatty acids significantly reduced cardiovascular mortality, non-fatal myocardial infarction, coronary heart disease events, major adverse cardiovascular events, and revascularization.
EPA and DHA therapy are types of omega 3 therapy. EPA monotherapy showed an 18% reduction in mortality compared to EPA + DHA, but omega-3 supplementation was associated with a higher risk of atrial fibrillation and bleeding, particularly with EPA alone.
Observational Long-term omega-3 supplementation, particularly DHA, was linked to a 20% reduced risk of Alzheimer's disease (AD) or cognitive decline. A study showed long-term omega-3 users had a 64% lower risk of AD, with higher DHA or EPA intake reducing cognitive decline by 8-9.9%. However, those taking the supplement may be more likely to follow a healthy lifestyle hence the red
Evidence against it?
Vital RTC In this large randomised trial of over 25,000 adults, daily omega-3 supplementation (1 g/day) did not significantly reduce major cardiovascular events or invasive cancer over 5.3 years compared to placebo. While there was no effect on stroke, cancer death, or overall mortality, a significant reduction in heart attacks was observed.
Overall, omega-3s did not lower the risk of cardiovascular disease or cancer in the general population, though they may reduce heart attack risk. ASCEND trial In this large randomised trial of 15,480 patients with diabetes but no prior cardiovascular disease, daily omega-3 supplementation (1 g/day) did not reduce the risk of serious vascular events compared to placebo over 7.4 years. A serious vascular event occurred in 8.9% of the omega-3 group and 9.2% of the placebo group. The combined outcome of a vascular event or revascularization occurred in 11.4% and 11.5% of participants, respectively, and all-cause death in 9.7% and 10.2%. The study found no significant cardiovascular benefit of omega-3 supplementation in this population.
Best bioavailable form?
Capsule or liquid
Advice on taking it?
16 ounces (two 8-ounce servings) of fatty fish per week