International Omega-3 Learning and Education Consortium for Health and Medicine

The long-chain omega-3 fatty acid EPA has recently been investigated for its effects on cardiovascular health. Specifically, the effects of EPA on major coronary events were investigated in a large Japanese study known as the JELIS trial (Japan EPA Lipid Intervention Study). Conducted over a 5-year period, the JELIS trial was designed to test the hypothesis that long-term supplementation with 1800 mg/day EPA would prevent major coronary events in hypercholesterolemic patients in Japan.

The obesity-associated metabolic syndrome epidemic is a significant health care concern today. The most recent study from the World Health Organization approximates that, globally, 1.6 billion adults are overweight with at least 400 million adults classified as obese (1). Obesity is a major susceptibility factor leading to the development of various conditions of the metabolic syndrome. Chronic morbidities due to insulin resistance, hypertension, and dyslipidemia are metabolic abnormalities that are included in the disorder (2). The association between excess body fat accumulation and the metabolic syndrome has been documented (3).

There is considerable evidence from population studies that higher maternal intakes of fish and seafood containing long-chain omega-3 fatty acids such as DHA (docosahexaenoic acid, 22:6 n-3) plus EPA (eicosapentaenoic acid, 20:5 n-3) or DHA/EPA via supplementation can benefit neurodevelopmental outcomes in children 4-8 years of age (1,2,3). The accretion of DHA in the brain, while particularly pronounced up to 2 years of age, has been found to progressively increase in the cerebral cortex up to 18 years of age (4,5).

Staple food products enriched with omega-3 fatty acids provide a low dose, long-term supply of the essential omega-3 fatty acids. Research on these fortified food products has shown that the omega-3 fatty acids that are added into traditional food products are absorbed by and incorporated into the blood lipids to be available for the biochemical and physiological functions in the body. Yep et al (1) showed that supplementing human participants with as little as 60 mg of long-chain omega-3 fatty acid per day from bread that contained microencapsulated tuna oil (MTO, 20 mg of long-chain n-3 PUFA / slice) for three weeks significantly increased the proportions of 20:5n-3, 22:5n-3 (EPA), 22:6n-3 (DHA), and total n-3 PUFA in plasma.

Inflammation is a normal defense mechanism that protects the host from infection and other insults; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites (1). It is typified by redness, swelling, heat, pain and loss of function, and involves interactions amongst many cell types and the production of, and responses to, a number of chemical mediators. Where an inflammatory response does occur, it is normally well regulated in order that it does not cause excessive damage to the host, is self-limiting and resolves rapidly. This self-regulation involves the activation of negative feedback mechanisms such as the secretion of anti-inflammatory cytokines, inhibition of pro-inflammatory signaling cascades, shedding of receptors for inflammatory mediators, and activation of regulatory cells. As such, when controlled properly, regulated inflammatory responses are essential to remain healthy and maintain homeostasis.

The European Union will leap ahead of other governments in its recognition of EPA and DHA omega-3 fatty acids' benefits with legislation that will establish multiple health claims, nutrition claims, and intake targets for EPA and DHA. The European Food Safety Agency (EFSA) is considering recommending a Dietary Reference Value (DRV) of 250mg EPA+DHA intake per day, based on reducing cardiac mortality risk. The level is controversial because many leading scientists believe 500mg is more appropriate, but EFSA noted that a recent paper suggested that intakes over 250mg provided no additional cardioprotection. The level is not likely to change until this issue is addressed, but papers currently being published do exactly that.

This is one of the most commonly asked questions about omega-3 fatty acids, and it naturally begs the question "what is enough?" Although the answer is and will continue to be the subject of intense investigation, in 2004 an important paper was published that will help define "enough." Harris and von Schacky proposed a new blood test called "the omega-3 index," and presented a case for why it should be considered as a new risk factor for fatal coronary heart disease.

Omega-3 fatty acids are notable for their protean physiological effects, including regulation of eicosanoid production, cell membrane physiology, gene expression and translation, and metabolism. Such diversity of action allows omega-3 fatty acids to be investigated as potential therapy in a variety of disease states. In fact, there is active omega-3 research in many disparate medical fields.

Though omega-3 fatty acids are being applied to a variety of disease states; arguably, the most prominent and extensively investigated is in the area of cardiovascular illness. Such research began in the early 1970s with the discovery that Northern European Eskimos, whose food intake was limited primarily to omega-3 fatty acid rich fatty animal meats and fish, had substantially lower levels of blood lipids and lower rates of heart disease than their European counterparts, who consumed a less fatty, more "balanced" diet (1). Since then, omega-3 fatty acids have been linked to salutary cardiovascular effects.