Two parts of the safflower are primarily used: the flower itself and safflower seeds. There are two types of safflower oil with corresponding types of safflower varieties: those high in monounsaturated fatty acid (oleic) and those high in polyunsaturated fatty acid (linoleic). Currently, the seed varieties that produce oil high in oleic acid and very low in saturated fatty acids predominate in the United States market. High oleic safflower oil is lower in saturates and higher in monounsaturates than olive oil. In the U.S. diet, safflower oil has been frequently substituted for oils with higher saturated fat content, as monounsaturated fat may have a beneficial effect on the risk of coronary heart disease. Some clinical studies have shown that safflower oil supplementation may be helpful in patients with cystic fibrosis, Friedreich's ataxia, and neurotoxicity from lithium. However, more study is needed in these areas before a firm conclusion can be drawn. In traditional Chinese medicine, safflower is used to invigorate the blood, dissipate stasis, amenorrhea (absence of menstruation), pain, and traumatic injuries. It is also used to "calm" a live fetus and abort a dead fetus, and is therefore used cautiously during pregnancy.
Dietary sources of omega-3 fatty acids include fish oil and certain plant/nut oils. Fish oil contains both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), while some nuts (e.g., English walnuts) and vegetable oils (e.g., canola, soybean, flaxseed/linseed, and olive oil) contain alpha-linolenic acid (ALA). Evidence from several studies has suggested that amounts of DHA and EPA in the form of fish or fish oil supplements lowers triglycerides, slows the buildup of atherosclerotic plaques ("hardening of the arteries"), lowers blood pressure slightly, as well as reduces the risk of death, heart attack, dangerous abnormal heart rhythms, and strokes in people with known heart disease. However, high doses may have harmful effects, such as an increased risk of bleeding. Although similar benefits are proposed for alpha-linolenic acid, scientific evidence is less compelling, and beneficial effects may be less pronounced. Some species of fish carry a higher risk of environmental contamination, such as with methylmercury.