Omega-3 Fish Oil
EPA and DHA contribute to the normal function of the heart. DHA contributes to the maintenance of normal brain function.
Also known as Fish Oil, EPA, DHA, Omega 3, Omega-3
Common doses
1000-3000 mg
Best timing
Morning
Food
Take with food
Interactions
4 known
Omega-3 fatty acids (EPA and DHA) are essential polyunsaturated fats that the body cannot produce efficiently from plant-based omega-3 (ALA). They are structural components of cell membranes, particularly in the brain and retina, and produce anti-inflammatory signalling molecules called resolvins and protectins.
The modern Western diet is dramatically skewed toward omega-6 fatty acids (from vegetable oils) at the expense of omega-3s, with ratios reaching 20:1 when the evolutionary ratio was closer to 1:1. This imbalance is associated with chronic inflammation. Fish oil supplementation aims to rebalance this ratio.
Dose matters significantly for fish oil. Most research showing benefits uses 1-4 grams of combined EPA+DHA daily, which is far more than the 300 mg in a standard fish oil capsule. Read the label for EPA+DHA content, not total fish oil.
Key benefits
Heart health
EPA and DHA contribute to the normal function of the heart. Benefits are most pronounced at doses of 2+ grams EPA+DHA daily.
Brain function
DHA contributes to the maintenance of normal brain function. DHA makes up approximately 40% of the polyunsaturated fatty acids in the brain.
Inflammation
EPA and DHA produce anti-inflammatory resolvins and protectins, and compete with pro-inflammatory omega-6 fatty acids for enzymatic conversion.
Eye health
DHA contributes to the maintenance of normal vision. It is a major structural component of the retina.
Available forms
Triglyceride Form
The natural form found in fish. Better absorbed than ethyl ester. More expensive. Look for 're-esterified triglyceride' (rTG) on the label.
Ethyl Ester
The most common supplement form. Created during concentration. Slightly lower absorption. Cheaper.
Phospholipid Form (Krill Oil)
Omega-3s bound to phospholipids. May have better bioavailability per gram. Also contains astaxanthin. Typically lower total EPA+DHA per capsule.
Algal Oil
Vegan DHA (and sometimes EPA) from microalgae. The original source that fish get their omega-3s from. Good option for vegetarians.
Food sources
- Fatty fish (salmon, mackerel, sardines, anchovies)
- Oysters and mussels
- Fish roe (caviar)
- Algae (vegan DHA source)
- Walnuts and flaxseed (ALA, poorly converted)
Signs of deficiency
- Dry skin and hair
- Poor concentration
- Joint pain and stiffness
- Mood changes
- Dry eyes
- Brittle nails
Upper intake limit
3,000 mg EPA+DHA/day from supplements (FDA generally recognized as safe). Higher doses used therapeutically under medical supervision. High doses may increase bleeding time.
Research summary
Strong evidence for triglyceride reduction at 2-4 g/day (Vascepa trial). Good evidence for cardiovascular benefit in secondary prevention. Moderate evidence for depression (especially high-EPA formulations). The VITAL trial showed modest benefit for heart attacks in the general population. Quality matters: look for third-party tested products free of heavy metals and oxidation.
Known interactions (4)
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1 flagZinc and Iron compete for the same absorption pathway. Take at least 2 hours apart.
Supplements
This information is for educational purposes only. It is not medical advice and does not diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional.