Omega-3 fatty acids (fish oil) have been studied for more than 30 years, resulting in more than 7,000 reports, and nearly 900 human clinical trials. Omega-3 fatty acids have been shown to have positive effects on the heart, brain, joints, skin and even pregnancy. Studies have evaluated not only the multiple ways omega-3s promote cardiovascular health, but also the healthy functioning of many other biological activities.
Evolutionary Aspects of Diet
Studies of hunter-gatherer societies indicate that man evolved on a diet that was low in saturated fat (wild game, seeds, berries, fish), and the amounts of n-3 and n-6 fatty acids were quite equal (1:1). Over the past 10,000 years the development of agriculture has triggered changes in the food supply, especially during the last 100-150 years. This has led to increases in trans-fatty acids from the hydrogenation of vegetable oils, and an enormous increase in n-6 fatty acids (about 30g/day) due to the production of oils from vegetable seeds such as corn and safflower. There have also been large increases in meat consumption and large decreases in fish consumption. Even cultivated vegetables contain fewer n-3 fatty acids than do plants in the wild.
Why do I need more EPA and DHA omega-3 fatty acids?
Both omega-6s and omega-3s are essential fatty acids. According to experts and the World Health Organization, the optimal ratio between omega-6 and omega-3 is approximately 5:1. The average American’s ratio ranges from 12-18:1. The typical western diet is to blame. Our food supply contains an abundance of omega-6 fatty acids from vegetable oils such as corn oil, safflower oil, sunflower oil, and meat. Many metabolic/physiological functions depend on a balanced ratio between these two essential fatty acids. It is recommended that people try to improve this ratio as good health depends on it. To achieve optimum balance, we should attempt to consume fewer omega-6s (vegetable oils and meat) and more omega-3s (fish and fish oil). A very high omega-6/omega-3 ratio promotes the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3s exert suppressive effects.
What are the dietary recommendations for omega-3 intake?
The American Heart Association Dietary Guidelines recommends consuming two fish meals per week, with an emphasis on fatty fish (ie, salmon, herring and mackerel). Commercially prepared fried fish (eg, from restaurants and fast food establishments, as well as many frozen, convenience-type fried fish products) should be avoided because they are low in omega-3 and high in trans-fatty acids. For those who do not, or cannot eat fish, taking a quality omega-3 supplement is a good option.
Benefits of Omega-3 Fatty Acids:
Numerous studies have shown that omega-3 fatty acids enriched diets are associated with reduction of cardiovascular mortality, myocardial infarction and sudden death. Higher fish intake was associated with decreased incidence of coronary artery disease and cardiovascular mortality in several prospective cohort studies. Putting it in perspective, a minimum of one fish meal a week was associated with a 52% reduction in sudden cardiac death.
Rheumatoid arthritis is an autoimmune disease that is characterized by inflammation of the synovium (lining) of the joints. Several clinical trials favor the use of omega-3 fish oil in patients with rheumatoid arthritis and one double-blind placebo-controlled trial showed that the omega-3 supplementation of 130 mg/kg/day decreased the number of tender joints, duration of morning stiffness, pain and global arthritis activity versus placebo. This study suggests that fish oil supplementation may relieve some of the symptoms of rheumatoid arthritis and reduce the need for non-steroidal anti-inflammatory drug use. In addition, another study demonstrated that omega-3 fatty acids reduced the cartilage destroying enzymes responsible for joint destruction.
An alternative treatment with fewer side effects than NSAID medications that also reduces the inflammatory response and thereby reduces pain is believed to be omega-3 EFAs found in fish oil.
Omega-3 and Skin
Human skin acts as a barrier between the internal and external environments. Besides vital biological functions, the skin plays a pivotal role in the feeling of well-being and in physical attractiveness. Studies have shown that omega-3 fatty acids protect keratinocytes and fibroblasts from free radicals and immune mediators generated by sun exposure, helping to soothe the skin. Additionally, omega-3s help promote elasticity and hydration for smoother looking skin.
Mothers and Infants:
Omega-3 fatty acids use in pregnancy has shown promise in prolonging gestation and preventing preterm labor.
In 2002, the FDA approved supplementation of both omega-3 and omega-6 fatty acids in infant formula. Both are potentially important in fetal and infant neural development. Studies have shown that higher DHA content in formula is related to improved visual acuity and another study showed sustained increase in intelligence at 4 years of age in children whose mothers were supplemented with fish oil from 18 weeks of pregnancy to 3 months postpartum.
Brain, Mood, Personality:
The human brain is more than 60% structural fat, but about a fifth of that fat cannot be formed by the body and must be consumed in the diet. And, it has to be certain types of fats – omega-3s — and we no longer eat these types of fats as we did years ago. Worse, we eat man-made trans-fats and excessive amounts of saturated fats and vegetable oils high in omega-6 fatty acids, all of which interfere with our body’s attempt to utilize the tiny amount of omega-3 fats that it gets. Numerous studies have shown the beneficial effects of supplementing with omega-3s (EPA and DHA) in patients suffering from depression, bipolar and unipolar disorders as well as postpartum depression. Our grandmothers told us fish was “brain food” and now scientists have evidence to back the claim.
Numerous clinical trials in the past 30 years have studied the effects of omega-3 fatty acids on several disease states with positive results, heart disease in particular. Other studies have concluded that omega-3s have positive effects on weight control and obesity-related diseases, enhanced mental abilities in adults, age-related macular degeneration, lupus symptoms, menstrual pain, cancer, inflammation and autoimmune diseases, and chronic fatigue syndrome. Over 2,000 scientific studies have demonstrated the wide range of problems associated with omega-3 deficiencies. The American diet is almost devoid of omega-3s, except for certain types of fish. In fact, researchers believe that about 60% of Americans are deficient in omega-3 fatty acids, and about 20% have so little that test methods cannot even detect any in their blood. An optimal balance of omega-6/omega-3 fatty acids (approximately 5:1) is vital for good health.