So, Tell Me About Omega-3 Fatty Acids…
First classified as Vitamin F, Omega-3 (ω-3) fatty acids were discovered to have the chemical structure of polyunsaturated fats (for more information, see blog, “The Story on Trans Fat”) in the 1930’s. Omega-3’s are a type of essential fatty acids. Our bodies do not produce these, therefore they are ‘essential’ in our diet for proper growth and health maintenance.
Studies involving the Greenland Inuit Tribe in the 1970’s helped elucidate further health benefits of omega-3 fatty acids. Researchers noted the high consumption of fat from seafood among these people, but almost no cardiovascular disease. We subsequently learned that high consumption of omega-3 fatty acids reduces triglycerides, blood pressure, and atherosclerosis (hardening of the arteries).
In 2004, the FDA offered a qualified health claim. They reported, “supportive but not conclusive research shows that consumption of EPA and DHA [n−3] fatty acids (including omega-3’s) may reduce the risk of coronary heart disease.”
Additional health benefits include reduced inflammation (helpful in rheumatoid arthritis, lupus, Crohn’s, etc.), arrhythmia protection, ischemic (low blood-flow) stroke prevention, and even easing of depression and anxiety.
Omega-3 fatty acids help to strengthen our myelin (the protective sheath around our nerves that helps them send signals). Current research is examining potential benefits in cognitive functioning, attention-deficit hyperactivity disorder (ADHD), bipolar disease, schizophrenia, and developmental disorders.
If, however, omega-3 fatty acids are consumed at levels greater than 3 grams per day, detrimental effects may occur. Reports include the possibilities of increased bleeding, hemorrhagic (bleeding) stroke, difficult glucose control in diabetics, increased LDL (bad cholesterol) levels in the blood, and even death from cardiac arrhythmias in patients with congestive heart failure.
So, where do we get our omega-3 fatty acids? The most widely available source is cold water oily fish (highest content in salmon, herring, mackerel, anchovies, and sardines; tuna in lesser amounts). Although fish is a major dietary source for omega-3 fatty acids, they are also ‘essential’ in the fish diet. The omega 3’s are actually produced by algae and plankton. We obtain further omega 3 fatty acids from pure fish oil, krill oil, plant sources like flaxseed, black raspberries, hemp, and pecans, fortified eggs, and meats such as lamb.
The American Heart Association has made dietary recommendations for daily intake relative to cardiovascular benefits and risks. Individuals with no history of coronary artery disease or myocardial infarction (heart attack) should consume oily fish or fish oils two times per week. Those with history of coronary disease or myocardial infarction should consume 1 gram of Eicosapentaenoic acid (EPA) daily (an omega-3 fatty acid).
As we climb the fish food chain, heavy metals (mercury, lead, nickel, arsenic, and cadmium) and fat-soluble pollutants (dioxins, PCB’s) tend to accumulate within the fish. Fortunately, most heavy metals selectively bind to proteins within the fish, and do not accumulate within the fish oil. Thus, consumption of pure fish oils may avoid unwanted toxicity.