Omega-3 oils may offer protection from coronary heart disease, though a recent review of multiple studies in the British Medical Journal didn't find a clear effect. Choose dietary sources over fish-oil supplements, which may be contaminated with heavy metals and carcinogenic manmade chemicals. Opt for small oily fish, hemp and linseed (flax) oils, argan oil, and lingonberries. Grassfed meat and organic cheese are also good. Avoid margarine: it may contain artery-clogging trans fat.