Polyunsaturated fatty acids (PUFAs), particularly omega-3 fatty acids (such as EPA and DHA found in fish oil), have been investigated for cardiovascular benefits, including for angina pectoris. The scientific rationale is based on their ability to reduce triglyceride levels, exert anti-inflammatory effects, improve endothelial function, and lower the risk of thrombosis. However, high-quality evidence specifically supporting the use of PUFAs to treat or reduce symptoms of angina is limited.

Early observational studies and some small clinical trials suggested potential benefits, such as decreased frequency of angina attacks or improved exercise tolerance. These effects were thought to be due to improvements in heart muscle oxygenation and reduced arterial stiffness. However, larger and more recent randomized controlled trials (RCTs) and meta-analyses have not consistently shown a significant benefit for PUFAs in reducing angina symptoms or major adverse cardiovascular events in patients with established coronary artery disease.

Current clinical guidelines do not specifically recommend PUFAs for the treatment of angina, though they may be suggested as part of a heart-healthy diet to reduce overall cardiovascular risk. The overall evidence supporting their direct use in angina is therefore limited (rated 2/5), with benefits more clearly established for broader cardiovascular prevention rather than for angina management per se.