Triglycerides and cholesterol are two different types of fats found circulating in the blood. Surplus calories, not needed for immediate use, are stored in the body as triglycerides and can be converted to energy as needed. Cholesterol is employed in cell building and the production of a variety of hormones. Since these fats do not dissolve in blood, they continue to circulate in the blood as lipoproteins, where the cholesterol and triglycerides are carried in the bloodstream hooked to proteins whose job is to transport such lipids.
There are three main categories of lipoproteins, low density lipoproteins (LDL or bad cholesterol), high density lipoprotein (HDL or good cholesterol) and very low density lipoproteins (VLDL). LDL promotes cardiovascular diseases while HDL protects against it. Elevated cholesterol levels in the blood can lead to coronary artery disease, while high levels of triglycerides are a mild risk factor for heart disease but greater risk for acute pancreatitis.
Fish oil consists of polyunsaturated Omega-3 fatty acids, among them DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) which are known to promote heart health. A number of studies indicate that use of fish oil aides in bringing down blood pressure and heart rate, ease inflammation, improve blood vessel function and at enhanced doses reduce triglycerides which play a role in the onset of atherosclerosis.1
According to one study published in the American Journal of Clinical Nutrition, the LDL (bad) cholesterol was best reduced in a group of test patients given 4 grams of EPA + DHA (found in fish oil), in combination with 2 grams of Gamma-Linolenic Acid.2 In another Japanese EPA Lipid Intervention Study (JELIS) participants who consumed EPA along with a cholesterol-lowering drug, reduced their chances of suffering from a major cardiac arrest, angina, blocked coronary arteries compared to those who took the cholesterol lowering drug alone.3
An earlier study found that while fish oil increased the amount of LDL the blood, it cut down on the ability of LDL to carry cholesterol. To better under this finding, it is important to note that LDL is nothing more than a parcel for carrying cholesterol. Without the cholesterol fat attached to this parcel, it is unable to cause the hardening of the arteries. The net result of fish oil is that it does not increase over all cholesterol levels, because it reduces the quantity of cholesterol that can be transported through the blood when it does not allow LDL to become attached to cholesterol. This produces an overall positive result for cardiovascular health. Furthermore, the study found that supplements of fish oil inhibit the synthesis of thromboxane, the lipid necessary for blood clotting. By cutting down on its production, fish oil reduces the danger of blood clots, stroke and cardiovascular infractions.4
- Leaf A. Prevention of sudden cardiac death by n-3 polyunsaturated fatty acids. J Cardiovasc Med. (Hagerstown). 2007; 8 Suppl 1:S27-29.
- Yokoyama M, Origasa H, Matsuzaki M, et al. Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomised open-label, blinded endpoint analysis. Lancet. 2007; 369:1090-98.