An introduction to dietary/supplemental omega-3 fatty acids for general health and prevention: Part 1.
An introduction to dietary/supplemental omega-3 fatty acids for general health and prevention: Part 1.
Year: 2005
Authors: Moyad, MA.
Publication Name: Urologic Oncology: Seminars and Original Investigations.
Publication Details: Volume 23, Page 28.
Abstract:
One of the most intriguing and highly researched areas is the impact of omega-3 fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosohexaenoic acid (DHA) on the prevention of a variety of conditions including cardiovascular disease, arthritis, certain cancers, depression, maternal and child health, neurological diseases, and osteoporosis. In part 1 of this manuscript, a number of landmark studies are discussed that demonstrate the important role that omega 3 fatty acids play in the prevention of certain CVD conditions. In the Lyon Diet Heart Study (1994), participants with previous history of cardiac events were allocated to consume either a control diet or a Mediterranean ALA-rich diet rich (intervention group). The intervention diet consisted of significantly less fat, saturated fat, cholesterol, and linoleic acid, with more oleic acid and ALA (1.8 g/day from a canola-based margarine). After only 27-months, a significant reduction in cardiac events was observed in the intervention group compared to the control group. In fact, the study was originally funded for 5-years, however, the study was terminated early by its Science and Ethics Review Committee due to the dramatic beneficial impact in the intervention group. The Indian Experiment of Infarct Survival Study (1997) included 360 patients who had suffered a previous acute myocardial infarction (MI). Patients were allocated to consume a placebo, 1.8g fish oil, or mustard seed oil (2.9g ALA) daily beginning approximately 18 hours after onset of symptoms. After 1 year, total cardiac events and nonfatal infarctions were significantly reduced in the fish oil and mustard oil groups compared to the placebo group. Fish oil and mustard oil groups also demonstrated a significant reduction in total cardiac arrhythmias, left ventricular enlargement, and angina compared to the control group. Fish and fish oil have been evaluated for effects on the end points of CVD. In the Diet and Reinfaction Trial (Dart – 1989) a 29% reduction in all-cause mortality was observed after 2 years of follow up in 1015 men who received a recommendation to eat oil fish (200-400g portions twice weekly) compared to 1018 men who did not receive this specific advice. Similar results were also observed in additional trials investigating the effect of fish oils or EPA/DHA on various CVD endpoints, including the US Physician Health Study (1998) and the GISSI-Prevenzione trial (1999). An “omega-3 test for CHD” has been developed in which the level of erythrocyte EPA + DHA levels can be associated with risk of mortality from CHD – particularly sudden cardiac death. Based on past primary and secondary trials, an omega-3 index of more than or equal to 8% is associated with the highest level of cardio-protection, while an index of less than or equal to 4% is associated with the least amount of cardio-protection.
