Omega-3 fatty acids are considered essential fatty acids:
They are necessary for human health but the body can’t make them — you have to get them through food.
Omega-3 fatty acids can be found in fish, such as salmon, tuna, and halibut, other seafood including algae and krill, some plants, and nut oils.
Also known as polyunsaturated fatty acids (PUFAs), omega-3 fatty acids play a crucial role in brain function as well as normal growth and development.
They have also become popular because they may reduce the risk of heart disease. The American Heart Association recommends eating fish (particularly fatty fish such as mackerel, lake trout, herring, sardines, albacore tuna, and salmon) at least 2 times a week.
Research shows that omega-3 fatty acids reduce inflammation and may help lower risk of chronic diseases such as heart disease, cancer, and arthritis.
Omega-3 fatty acids are highly concentrated in the brain and appear to be important for cognitive (brain memory and performance) and behavioral function. In fact, infants who do not get enough omega-3 fatty acids from their mothers during pregnancy are at risk for developing vision and nerve problems. Symptoms of omega-3 fatty acid deficiency include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.
It is important to have a balance of omega-3 and omega-6 (another essential fatty acid) in the diet. Omega-3 fatty acids help reduce inflammation, and most omega-6 fatty acids tend to promote inflammation. The typical American diet tends to contain 14 – 25 times more omega-6 fatty acids than omega-3 fatty acids.
The Mediterranean diet, on the other hand, has a healthier balance between omega-3 and omega-6 fatty acids. Many studies have shown that people who follow this diet are less likely to develop heart disease. The Mediterranean diet does not include much meat (which is high in omega-6 fatty acids) and emphasizes foods rich in omega-3 fatty acids, including whole grains, fresh fruits and vegetables, fish, olive oil, garlic, as well as moderate wine consumption.
Uses:
Clinical evidence is strongest for heart disease and problems that contribute to heart disease, but omega-3 fatty acids may also be used for:
High cholesterol:
People who follow a Mediterranean-style diet tend to have higher HDL or “good” cholesterol levels, which help promote heart health. Inuit Eskimos, who get high amounts of omega-3 fatty acids from eating fatty fish, also tend to have increased HDL cholesterol and decreased triglycerides (fats in the blood). Several studies have shown that fish oil supplements reduce triglyceride levels. Finally, walnuts (which are rich in alpha linolenic acid or LNA, a type of omega-3 fatty acid) have been reported to lower total cholesterol and triglycerides in people with high cholesterol levels.
High blood pressure:
Several clinical studies suggest that diets or fish oil supplements rich in omega-3 fatty acids lower blood pressure in people with hypertension. An analysis of 17 clinical studies using fish oil supplements found that taking 3 or more grams of fish oil daily may reduce blood pressure in people with untreated hypertension.
Heart disease:
One of the best ways to help prevent heart disease is to eat a diet low in saturated fat and to eat foods that are rich in monounsaturated and polyunsaturated fats (including omega-3 fatty acids). Clinical evidence suggests that EPA and DHA (eicosapentaenoic acid and docosahexaenoic acid, the two omega-3 fatty acids found in fish oil) help reduce risk factors for heart disease, including high cholesterol and high blood pressure. Fish oil has been shown to lower levels of triglycerides (fats in the blood), and to lower risk of death, heart attack, stroke, and abnormal heart rhythms in people who have already had a heart attack. Fish oil also appears to help prevent and treat atherosclerosis (hardening of the arteries) by slowing the development of plaque and blood clots, which can clog arteries.
Large population studies suggest that getting omega-3 fatty acids in the diet, primarily from fish, helps protect against stroke caused by plaque buildup and blood clots in the arteries that lead to the brain. Eating at least 2 servings of fish per week can reduce the risk of stroke by as much as 50%. However, high doses of fish oil and omega-3 fatty acids may increase the risk of bleeding. People who eat more than 3 grams of omega-3 fatty acids per day (equivalent to 3 servings of fish per day) may have higher risk for hemorrhagic stroke, a potentially fatal type of stroke in which an artery in the brain leaks or ruptures.
Diabetes:
People with diabetes often have high triglyceride and low HDL levels. Omega-3 fatty acids from fish oil can help lower triglycerides and apoproteins (markers of diabetes), and raise HDL, so eating foods or taking fish oil supplements may help people with diabetes. Another type of omega-3 fatty acid, ALA (from flaxseed, for example) may not have the same benefit as fish oil. Some people with diabetes can’ t efficiently convert LNA to a form of omega-3 fatty acids that the body can use. Also, some people with type 2 diabetes may have slight increases in fasting blood sugar when taking fish oil, so talk to your doctor to see if fish oil is right for you.