Omega-3 fatty acids support several aspects of men’s health, from heart protection and hormone balance to sperm quality and mood. The benefits are well-documented across large clinical trials, and the effects are especially pronounced for cardiovascular risk, testosterone function, and reproductive health.
Heart Disease Protection
Heart disease is the leading cause of death in men, and this is where omega-3s have the strongest evidence. The VITAL trial, one of the largest supplement studies ever conducted, found that omega-3 supplementation reduced heart attacks by 28% compared to placebo across the general population. For men who ate little fish before starting supplements, the reduction was even larger: 40%. And for people with two or more heart disease risk factors (think high blood pressure, high cholesterol, smoking, or family history), heart attacks dropped by 44%.
A separate trial called REDUCE-IT looked at people already at high cardiovascular risk and found that daily omega-3 use over five years cut the rate of major cardiovascular events, including both heart attacks and strokes, by 25%. The American Heart Association recommends prescription-strength omega-3s at 4 grams per day specifically for lowering dangerously high triglyceride levels, one of the key blood fats tied to heart disease.
Testosterone and Reproductive Health
This is where omega-3s offer something uniquely relevant to men. A study of nearly 1,700 young men (median age around 19) found that fish oil supplementation was associated with higher semen volume, higher total sperm count, and larger testicular size. The effects were dose-dependent: men who took fish oil for 60 or more days had 0.64 mL higher semen volume and 1.5 mL larger testicular size compared to men who took no supplements. Even shorter use (under 60 days) showed measurable improvements.
The hormonal picture was equally notable. Men taking fish oil had an 8% higher ratio of free testosterone to luteinizing hormone, which suggests the testes were more efficient at producing testosterone per unit of hormonal signal. They also had 20% lower levels of follicle-stimulating hormone and 16% lower luteinizing hormone, both markers consistent with healthier baseline testicular function. For men thinking about fertility or simply wanting to support their hormonal health, this is one of the more compelling supplement findings available.
Prostate Health
The relationship between omega-3s and prostate cancer has been debated for years, with some earlier observational studies raising concerns. But a 2024 randomized clinical trial published in the Journal of Clinical Oncology provided more targeted evidence. Researchers assigned 100 men with low-grade prostate cancer on active surveillance to either a high omega-3, low omega-6 diet with fish oil or a control group, then tracked them for a year.
The results were striking. A key marker of cell proliferation (which indicates how aggressively cancer cells are dividing) decreased by about 15% in the fish oil group while increasing by roughly 24% in the control group. That marker is directly tied to prostate cancer progression, metastasis, and death. The trial didn’t show changes in tumor size or PSA levels over the one-year period, so this isn’t a treatment for prostate cancer. But it suggests omega-3s may slow the biological activity that drives progression in early-stage disease.
Mood and Mental Health
Depression affects men differently than women, and men are significantly less likely to seek treatment. Omega-3s, particularly EPA, have shown consistent benefits for depressive symptoms in clinical trials. The most effective formulations contain at least 60% EPA relative to DHA, at doses between 1 and 2 grams per day. Higher doses (up to 6 to 10 grams per day) have been tested, but the 1 to 2 gram range is what most evidence supports for mood improvement.
EPA appears to be the active player for mood. DHA is more associated with brain structure and cognitive maintenance, while EPA has stronger anti-inflammatory effects in the brain that seem to directly influence depressive pathways. If you’re choosing a supplement with mood in mind, check the label for the EPA-to-DHA breakdown rather than just the total omega-3 count.
How Much You Need
The official adequate intake for adult men is 1.6 grams per day of ALA, the plant-based omega-3 found in flaxseed, walnuts, and chia seeds. But ALA converts poorly to EPA and DHA in the body (typically under 10%), so meeting the ALA target alone won’t deliver the cardiovascular or hormonal benefits described above. Those require preformed EPA and DHA from fish or supplements.
There’s no official government recommendation for EPA and DHA intake specifically, but the FDA allows supplement labels to suggest up to 2 grams per day of combined EPA and DHA. For general heart health, 1 to 2 grams per day is the range most commonly used in successful trials. For high triglycerides, the therapeutic dose is 4 grams per day under medical guidance.
Best Food Sources
Fatty fish is the most concentrated natural source of EPA and DHA. Per 100-gram serving (roughly 3.5 ounces), here’s what the top options deliver:
- Atlantic mackerel: 2,500 mg combined EPA and DHA
- King mackerel: 2,200 mg
- Atlantic salmon (farmed): 1,800 mg
- Lake trout: 1,600 mg
- Chinook salmon: 1,400 mg
- Sockeye salmon: 1,200 mg
- Sardines (canned): 1,000 mg
- Rainbow trout: 500 mg
Two servings of fatty fish per week gets most men into the 1 to 2 gram range without supplements. A single serving of Atlantic mackerel or farmed salmon essentially covers a full day’s worth in one meal. If you don’t eat fish regularly, a quality fish oil supplement standardized for EPA and DHA content is the most practical alternative. Look for one that lists the EPA and DHA amounts separately on the label, since “1,000 mg fish oil” often contains only 300 to 500 mg of actual EPA and DHA.