General supplements show little benefit, though high-dose prescription formulas help specific patients.
What the evidence shows
Populations that eat a lot of oily fish tend to have less heart disease, which made omega-3 supplements a best-selling 'heart pill.' But observational patterns do not prove the pills themselves help.
A meta-analysis of 10 trials with nearly 78,000 people (Aung et al., 2018) found that routine omega-3 supplements did not significantly reduce heart attacks, strokes, or cardiovascular death. However, later high-dose prescription trials in specific high-risk patients (such as those with high triglycerides) have shown benefits, and the field remains active. The everyday claim — that a standard fish-oil capsule protects the general population's hearts — is not supported; targeted, high-dose use under medical guidance is a different, more promising case.
Sources
Aung, T., Halsey, J., Kromhout, D., et al. (2018). Associations of omega-3 fatty acid supplement use with cardiovascular disease risks: Meta-analysis of 10 trials involving 77 917 individuals.
JAMA Cardiology, 3(3), 225–234
Routine omega-3 supplementation did not significantly reduce coronary events or cardiovascular death.
DOI: 10.1001/jamacardio.2017.5205 →