The human body can make most of the types of fats it needs from other fats or raw materials. That isn’t the case for omega-3 fatty acids (also called omega-3 fats and n-3 fats). These are essential fats—the body can’t make them from scratch but must get them from food. Foods high in Omega-3 include fish, vegetable oils, nuts (especially walnuts), flax seeds, flaxseed oil, and leafy vegetables.

What makes omega-3 fats special? They are an integral part of cell membranes throughout the body and affect the function of the cell receptors in these membranes. They provide the starting point for making hormones that regulate blood clotting, contraction and relaxation of artery walls, and inflammation. They also bind to receptors in cells that regulate genetic function. Likely due to these effects, omega-3 fats have been shown to help prevent heart disease and stroke, may help control lupus, eczema, and rheumatoid arthritis, and may play protective roles in cancer and other conditions.

Omega-3 fats are a key family of polyunsaturated fats. There are three main omega-3s:

  • Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) come mainly from fish, so they are sometimes called marine omega-3s.
  • Alpha-linolenic acid (ALA), the most common omega-3 fatty acid in most Western diets, is found in vegetable oils and nuts (especially walnuts), flax seeds and flaxseed oil, leafy vegetables, and some animal fat, especially in grass-fed animals. The human body generally uses ALA for energy, and conversion into EPA and DHA is very limited.

The strongest evidence for a beneficial effect of omega-3 fats has to do with heart disease. These fats appear to help the heart beat at a steady clip and not veer into a dangerous or potentially fatal erratic rhythm. (1) Such arrhythmias cause most of the 500,000-plus cardiac deaths that occur each year in the United States. Omega-3 fats also lower blood pressure and heart rate, improve blood vessel function, and, at higher doses, lower triglycerides and may ease inflammation, which plays a role in the development of atherosclerosis.

Several large trials have evaluated the effect of fish or fish oils on heart disease. In the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardio (known as the GISSI Prevention Trial), heart attack survivors who took a 1-gram capsule of omega-3 fats every day for three years were less likely to have a repeat heart attack, stroke, or die of sudden death than those who took a placebo. Notably, the risk of sudden cardiac death was reduced by about 50 percent. In the more recent Japan EPA Lipid Intervention Study (JELIS), participants who took EPA plus a cholesterol-lowering statin were less likely to have a major coronary event (sudden cardiac death, fatal or nonfatal heart attack, unstable angina, or a procedure to open or bypass a narrowed or blocked coronary artery) than those who took a statin alone.

Here are other evidence of omega-3 benefits:

1. Omega-3 benefits your heart health. An Italian study (GISSI)of 11,324 heart attack survivors found that patients supplementing with fish oils markedly reduced their risk of another heart attack, stroke, or death. In a separate study, American medical researchers reported that men who consumed fish once or more every week had a 50 percent lower risk of dying from a sudden cardiac event than do men who eat fish less than once a month.

2. Omega-3 normalizes and regulates your cholesterol triglyceride levels.Compared to a statin, both fish oil and krill oil are more efficient in doing this. According to a study comparing the efficiency of krill and fish oils in reducing triglyceride levels, both oils notably reduced the enzyme activity that causes the liver to metabolize fat, but krill had a more pronounced effects, reducing liver triglycerides significantly more.

Fasting triglyceride levels are a powerful indication of your ability to have healthy lipid profiles, which can be indicative of your heart health.

Studies have also shown that omega-3 fats are anti-arrhythmic (preventing or counteracting cardiac arrhythmia), anti-thrombotic (prevents thrombosis or a blood clot within a blood vessel), anti-atherosclerotic (preventing fatty deposits and fibrosis of the inner layer of your arteries), and anti-inflammatory (counteracting inflammation – the heat, pain, swelling, etc).

3. DHA affects your child’s learning and behavior. Do you want to maximize your child’s intellectual potential? A study published in Plos One in June 2013 linked low levels of DHA with poorer reading, and memory and behavioral problems in healthy school-age children. In another study published in theAmerican Journal of Clinical Nutrition in August 2013, children who consumed an omega-3 fat supplement as infants scored higher on rule learning, vocabulary, and intelligent testing at ages 3 to 5.

Previous research also found that children with attention deficit hyperactivity disorder (ADHD) and related behavior or learning disabilities are more likely to have low omega-3 fat levels.

Omega-3 has such great impact on your brain health – EPA and DHA keep the dopamine levels in your brain high, increase neuronal growth in the frontal cortex of your brain, and increase cerebral circulation.

Omega-3 has been found to save the lives of children going through short bowel syndrome, which is uncommon but impacts thousands of people in the United States. SBS can occur from birth (when a portion of the intestine fails to develop) or due to an infectious inflammatory disease striking premature newborns. In adults, it can be caused by surgery for Crohn’s disease or injury.