What are they? According to the Mayo Clinic, omega-3 fatty acids comprise numerous polyunsaturated fatty acids, but the a-linolenic acid (ALA), eicosapentaenoic acids (EPA), and docosahexaenoic acids (DHA) are the most important.

What do they do? Large population clinical studies have proven that DHA and EPA reduce the risk of death, heart attack, abnormal heart rhythms (known as arrhythmia), and stroke - especially amongst persons with a history of cardiovascular disease. Omega-3 fatty acids have also been found to lower cholesterol, blood pressure and slow artery hardening. Research has also shown that omega-3 fatty acids are beneficial for depression and anxiety, diabetes, asthma, poor learning and focus in children, rheumatoid arthritis, certain cancers, ulcerative colitis and Crohn's disease.

Where do they come from? Where ALA is mostly found in plant and nut oils, such as flaxseed oil, canola oil and walnuts and pumpkin seeds, the most readily available sources of EPA and DHA are cold-water fish like salmon, mackerel, anchovies, halibut, sardines and tuna.

How much is needed? For healthy men with no history of heart disease, the American Heart Association recommends eating a variety of fatty fish at least twice a week and including oils and other ALA rich foods in men's diets where possible. Many foods offer omega-3 supplementation, but the amounts are often negligible and are highly variable. To ensure men are getting adequate amounts of omega-3 fatty acids, doctors highly recommend omega-3 supplementation, especially for those men with high cholesterol.

For more information, read 'Heart Protection for Men with Omega-3 Fatty Acids.'