Omega-3 Index: At least three servings of fish a week and EPA and DHA supplements are needed to protect the heart
Consuming two servings of fish per week is not sufficient to reach the desirable level of the Omega-3 Index, a parameter that measures the level of EPA and DHA in red blood cells. According to recent research, in fact, to achieve an index value between 8 and 12%, synonymous with good cardiovascular and overall health, it is necessary to combine at least three servings of fish per week with omega-3 rich supplements.
This is what American researchers from OmegaQuant and the University of South Dakota (USA), including Professor William Harris, creator of the Omega-3 Index, reported in the scientific journal Prostaglandins, Leukotrienes and Essential Fatty Acids.
The percentage of EPA and DHA in red blood cells as an indicator of heart health
The Omega-3 Index indicates the amount of EPA and DHA relative to the total fatty acids present in the cell membranes of red blood cells—membranes that are easy to analyze and that better reflect long-term EPA and DHA intake, indicating the actual level of these substances in the body. The composition of polyunsaturated fatty acids in red blood cells is thus an indicator of nutritional status and cardiovascular risk. A high Omega-3 Index, between 8-12%, has been associated with a lower risk of coronary heart disease and coronary mortality in epidemiological studies, but it also seems to be linked to maintaining good general health, especially regarding vision, joints, and cognitive abilities. This tool was developed in 2004 as a parameter to estimate the risk of sudden cardiac death by William Harris, professor at the University of South Dakota, and Professor Clemens von Schacky, cardiologist at the University of Munich.
Professor Harris is also the creator of the Omega-3 Index Test, a minimally invasive test that easily measures EPA and DHA levels in the blood. The test for identifying the Omega-3 Index must be performed in laboratories following a strict quality management system to obtain fast, reliable, and reproducible results, useful for doctors and patients to estimate the risk of heart disease and to achieve adequate omega-3 levels, which help reduce the risk of heart attack and sudden death.
At least three servings of fish per week and proper supplementation are necessary
According to current recommendations from the American Heart Association, consuming one or two servings of fish per week is necessary to achieve an Omega-3 Index of 8%. The results of two cross-sectional studies published in Prostaglandins, Leukotrienes and Essential Fatty Acids comparing EPA and DHA levels consumed through fish and the Omega-3 Index found that to achieve an 8% Index, two servings of fish per week are insufficient; it is necessary to consume sources of these unsaturated fatty acids at least three times per week and supplement accordingly. These studies examined data from 3,458 people who underwent the Omega-3 Index test and answered questions about their dietary intake and supplement use. The results indicated that people who reported not taking omega-3 supplements and not eating fish had an average Index of 4.1%. Those who took supplements and consumed three EPA and DHA-rich meals weekly reached a value of 8.1%. “These results prompt a reconsideration of the optimal amount of omega-3 fatty acids to consume through diet or supplements,” said Harry Rice, vice president of regulatory and scientific affairs at the Global Organization for EPA and DHA (GOED).
According to Dr. Jackson, one of the study's authors, there is a discrepancy between the amount of EPA and DHA indicated by current recommendations (250-500 milligrams per day) and the amount most Americans need to reach an 8% Omega-3 Index, which corresponds to more than 800 milligrams of fish oil per day. To achieve this goal, EPA and DHA supplements can be added to the diet or fish oil sources increased to 4-5 servings per week. Recently, OmegaQuant developed a calculation system to help people estimate their omega-3 needs and adjust their diet and supplementation regime to achieve a good Omega-3 Index. For example, according to this tool, a man with an Omega-3 Index of 4.5% would need about 950 milligrams of EPA plus DHA daily to reach 8%. Considering that three servings of sockeye salmon per week provide about 410 milligrams of EPA and DHA daily, he would need to add supplements of approximately 500 mg per day of EPA and DHA. Alternatively, he could consume supplements containing the full dose of 900 milligrams of EPA and DHA daily. Whatever the approach, it should be maintained for at least 4 months to reach a new steady state of the Index.
An adequate intake of EPA and DHA cannot be achieved with only two servings of fish per week
Currently, recommendations for the general population suggest consuming two servings of fish per week and do not advise supplementation with fish oil products. In light of this study’s findings, it is unlikely that this regimen produces an 8% Omega-3 Index. Consuming at least three servings of fish per week plus an EPA and DHA supplement greatly increases the likelihood of reaching this goal. As suggested by the study’s authors, new dietary recommendations aiming to reach a target blood level would be necessary as an effective strategy to reduce the risk of heart disease.
Source: K.H. Jackson et al. ‘Association of reported fish intake and supplementation status with the omega-3 index”Prostaglandins, Leukotrienes and Essential Fatty Acids. March 2019, Volume 142, Pages 4-10.
