Fish oil, sold in capsules as supplements, is derived from the skin and liver of fish and is an excellent source of omega-3 fatty acids. Omega-3 fatty acids are considered essential as they cannot be produced by the body and must be consumed through diet or supplements. Fatty cold water fish, flaxseed oil and, to a lesser extent, soybean oil are rich in omega-3 fatty acids. A strong body of scientific evidence supports the health benefits, including decreased risk of chronic disease, of fish oils.
Functions of Omega-3 Fatty Acids
The two most import omega-3 fatty acids are commonly known as EPA and DHA. EPA and DHA produce hormone-like substances that reduce inflammation and perform critical functions in the body. Healthy brain function, immunity, vision and the contraction of muscles and blood vessels require omega-3 fatty acids. Omega-3 fatty acids are involved in the formation of blood clots and the transport and metabolism of fats. Deficiencies can lead to neurological conditions and abnormalities in vision, skin integrity, immunity and kidney and liver function. Altered fat metabolism increases the risk for cardiovascular disease.
Omega-3 fatty acids have been found to decrease triglycerides, a type fat in the bloodstream and raise high density lipoproteins, also known as the good cholesterol. Fish oils have been found to lower blood pressure and decrease formation of blood clots and buildup of plaque on the walls of the arteries, lowering the risk of heart attack and stroke. Natives from Alaska and Greenland who consume diets high in omega-3 fatty acids have a lower incidence of heart attack, stroke and cardiovascular disease.
Omega-3 fatty acids have been found to reduce the incidence of certain types of cancers, particularly colon cancer. Fish oils have been found to decrease inflammation in individuals with rheumatoid arthritis and reduce joint pain and stiffness when used in conjunction with prescribed medication. Further research is needed to validate the role of omega-3 fatty acids in treating mental disorders such as depression, Alzheimer's disease, bipolar and attention deficit disorder.
Food Sources or Capsules
The American Heart Association recommends eating fish two to three times a week for protective benefits. Salmon, mackerel, bluefish, anchovy, herring, sardines and trout contain 1 gram of omega-3 fatty acids per 3.5-ounce serving. Benefits of the use of fish oil capsules in place of fish is inconclusive, but the American Heart Association recommends supplementation for those with coronary artery disease. Fish oils supplements lack other nutrients such as protein, selenium and iodide naturally present in fish. Supplements can also be contaminated by pesticides and mercury and large doses can be toxic. Fish oil supplements should be used under the direction of a physician due to increased risk for toxicity, excess bleeding and poor wound healing.
- University of Maryland Medical Center: Omega-3 fatty acids
- Mayoclinic.com: fatty acids, fish oil, alpha-linolenic acid
- Nutrition Concepts and Controversies; Frances Sizer
- Fish smoked image by Sidoroff from Fotolia.com