March 18 (Bloomberg) — Eating food high in fish oils such as omega-3 doesn't reduce the risk of heart disease, raising questions about national guidelines promoting the fats as beneficial for cardiovascular health, researchers found.

The analysis of 72 previous studies showed insufficient support for nutritional recommendations by groups such as the American Heart Association that advocate high consumption of polyunsaturated fats like omega-3 and omega-6, which is found in corn and sunflower oils, as well as some nuts and seeds.

The findings released yesterday in the Annals of Internal Medicine are the latest to show that supplements and vitamins don't work as well as touted to help patients prevent diseases. While past studies showed fish oil can lower unhealthy blood fats, blood pressure and reduce the risk of a second heart attack, research in recent years contradicted those findings, suggesting it has limited heart benefits.