Heart disease kills more Americans than any other disease, according to Medline Plus of the National Library of Medicine. Heart disease is usually caused by coronary artery disease, which results from narrowing of blood vessels that supply the heart. High levels of blood cholesterol and other fats called triglycerides constitute a major cause of coronary artery disease. Consuming some types of fish and fish oil may be very beneficial in lowering levels of triglycerides and raising levels of high-density lipoprotein, or good cholesterol, leading to a reduced risk of heart disease.
HDL and Triglycerides
Cholesterol in the blood is combined with protein as lipoprotein. Low-density lipoprotein or LDL is bad cholesterol because it forms plaque in arteries that may cause atherosclerosis and heart problems. High-density lipoprotein or HDL is good cholesterol. MayoClinic.com calls HDL a cholesterol scavenger because it removes cholesterol from the blood and takes it to the liver where it is degraded. High levels of triglycerides in the blood also raise the risk of heart disease, although the precise mechanism for this effect is unknown.
Benefits of Fish Oil
Oil derived from some fish contains high concentrations of omega-3 fatty acids. These fats are polyunsaturated oils that have been studied extensively as a potential help for many diseases and conditions. The American Heart Association reports that consuming fish oil may help lower triglyceride levels while raising blood levels of good cholesterol, or HDL. A diet rich in fish is now recognized as a good strategy to lower the risk of cardiovascular disease.
Sources of Omega-3 Fatty Acids
Although oil from all fish contains omega-3 fatty acids, certain fatty, cold water species are especially good sources. Mackerel, salmon, herring, albacore tuna and sardines are very rich in omega-3 fatty acids. According to Medline Plus, 3.5 oz of fish provides about 1 g of omega-3 fatty acids. The American Heart Association recommends eating fish at least twice every week; however, it recommends avoiding shark, swordfish or tilefish because they contain high levels of mercury.
Omega-3 Fatty Acid Supplements
The best strategy for raising consumption of omega-3 fatty acids is to consume more fish. However, it is also possible to take supplements containing the oil. According to the National Center for Complementary and Alternative Medicine, fish oil is the natural supplement most commonly used by American adults.The American Heart Association states that a person with cardiovascular disease may need to add supplements to their regiment to gain the most benefit. Medline Plus recommends taking up to 3 g of omega-3 fatty acid supplements daily for people with high triglyceride levels. Anyone considering taking omega-3 fatty acid supplements, however, should first discuss this strategy with a doctor.
Side Effects
Regular consumption of fish or taking fish oil supplements is considered safe, according to Medline Plus. However, no one should consume more than 3 g of fish oil supplements each day. Minor side effects may also occur, including bad breath, heartburn, nausea, loose stool or a rash. Fish oil also has an anti-clotting effect, so it should not be combined with certain medications that may promote bleeding. Anyone beginning a regimen of fish oil supplements should first consult a doctor to discuss any possible drug interactions.
References
- Medline Plus: Fish Oil
- Medline Plus: Adding Fish Oil to Low-Fat/High-Carb Diet May Improve Cholesterol
- National Center for Complementary and Alternative Medicine: Omega-3 Supplements: An Introduction
- Medline Plus: Heart Diseases
- Health Castle: Health Benefits of Omega 3 fatty acids
- MayoClinic.com: HDL cholesterol: How to boost your 'good' cholesterol
