The Omega-3 Index: New Risk Factor for a Healthy Heart?
Low omega-3 levels: a future problem for hearts healthy today
Scientific evidence shows that the level of omega-3 fatty acids in the blood can be a new risk factor and proposes a new diagnostic tool – the Omega-3 Index – which can be easily used by anyone. This new diagnostic tool, consisting of a quantification of the fatty acid profile in an individual, could help doctors and patients at risk of heart disease to reach adequate levels of omega-3 fatty acids that, according to recent scientific research, ensure a measurable reduction in the risk of heart attack and sudden death. "To address the problem of so-called 'bad cholesterol' (LDL) in the future, cardiology associations could rightly recommend the consumption of EPA and DHA as a crucial therapeutic intervention to support heart health," write Clemens von Schacky from Ludwig-Maximilians-Universität in Munich and Prof. William Harris from the University of South Dakota. Numerous studies over time have linked the consumption of omega-3 fatty acids to a series of beneficial effects: for heart health, optimal fetal development during pregnancy, joint health, mood and behavior improvement, and prevention of certain types of cancer.
The new review of studies published online in Cardiovascular Research examined a set of epidemiological studies and four large-scale intervention studies, concluding that the scientific evidence supports the benefits of omega-3 consumption on heart health. The mechanism behind these beneficial effects is believed to be the incorporation of EPA and DHA into the membranes of heart cells, explain researchers Von Schacky and Harris. These fatty acids replace those present, positively altering the properties of the cells themselves. These changes involve the dilation of blood vessels favoring improved blood flow. This is followed by a reduction of inflammatory events and a lowering of blood triglyceride levels.
Since omega-3s become part of the composition of cell membranes, measuring omega-3 content at the level of heart cells could be fundamental as a primary marker of cardiovascular risk, argue Von Schacky and Harris. "The possibility that omega-3s could serve as biomarkers and thus have clinical prognostic utility should be seriously considered." Following these observations, Von Schacky and Harris propose the "omega-3 index" defined as the percentage of EPA and DHA relative to other fat categories present in red blood cell membranes as a new diagnostic tool for primary prevention.
Based on data in the scientific literature, the researchers calculated that an omega-3 index of 8% or higher is associated with a 90% reduction in the risk of sudden cardiac death compared to a value of 4% or lower. "A standard dose of one gram per day of omega-3, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), recommended by cardiology associations, is probably far from the ideal omega-3 intake for each of us, since not only the standard dose but also diet type, our genetic background, body mass index, and the combination of many other factors underlie the omega-3 fatty acid profile of a given person," write the researchers.
The risk of finding pollutants in oily fish, such as mercury, dioxins, and polychlorinated biphenyls (PCBs), has led some to reduce fresh fish consumption despite opposing considerations that benefits far outweigh the risks. At the same time, consumers increasingly seek omega-3s from safer sources. Von Schacky and Harris strongly recommend that pollutants be categorically avoided.
Source: Wolk A, Larsson SC, Johansson JE, Ekman P. Long-term fatty fish consumption and renal cell carcinoma incidence in women. JAMA. 2006 Sep 20;296(11):1371-6.
