Omega-3 fats from fish, called EPA and DHA, help your blood vessels relax and stay flexible by boosting a natural chemical (nitric oxide) that opens up arteries and reduces harmful stress in your body.

When scientists added a specific type of omega-3 fat (DHA) to blood vessel cells in a dish, it made them release a little more of a helpful molecule (nitric oxide) that keeps blood vessels relaxed, but didn’t change a harmful molecule (peroxynitrite) — and this effect was smaller than what another omega-3 fat (EPA) does.

Omega-3 fats from fish, called EPA and DHA, may help calm down harmful inflammation in your heart and blood vessels by blocking some of the body’s alarm signals, which could lower your risk of heart disease and heart failure.

When scientists added a type of omega-3 fatty acid called EPA to blood vessel cells in a dish, the cells made more of a helpful molecule (nitric oxide) and less of a harmful one (peroxynitrite), which might help keep blood vessels healthier and less inflamed.

Taking fish oil supplements with EPA and DHA might help keep your blood from clotting too easily, which could lower your chance of having a heart attack or stroke if you already have heart disease.

People with more of the good omega-3 fats (EPA and DHA) in their red blood cells tend to have less heart disease and do better over time if they already have heart problems.