Why is omega3 is good for you?

Happy Heart. Omega-3-fatty acids can lower your risk of heart attacks and sudden cardiac death [from bad heart rhythms]. O3-fa's lower bad high triglycerides and LDL cholesterol and increase good HDL cholesterol. They lower blood pressure too.
Controversial. They raise HDL (the "good") cholesterol but it's unclear that supplemental omega 3s are good for you. Fish is good for you and contains a lot of omega 3s, but also other things. Epidemiological studies show that cultures that consume a lot of fish (like the japanese) and little beef have a much lower incidence of heart attack. There is conflicting data that taking omega 3 supplements helps.