High Prevalence of Suboptimal Blood Levels of Omega-3 in US Population
Murphy, R. A. et al., Nutrients , 7: 10282-10289, 2015
Nutrition Science and Advocacy , DSM Nutritional Products, Parsippany , NJ, USA
Recommendations from federal agencies in the USA and elsewhere have advised upon target intakes of fish/seafood and the long-chain omega-3 (LC omega-3) fatty acids as EPA plus DHA for optimizing human health and protection against cardiovascular disease. Assessments of dietary intakes of EPA/DHA in the population at large are challenging due to the accuracy limitations of food frequency questionnaires and fatty acid compositional data on relevant food sources. Thus, blood measures of LC omega-3 are considered to be useful biomarkers for estimating their intakes and associated health risks. In the present population study, the levels of LC omega-3 fatty acids (EPA plus DHA plus DPA (docosapentaenoic acid)) as a % of total fatty acids in the total lipid from 1386 human plasma samples from adult Americans collected during 2003-2004 were determined by gas-liquid chromatographic analyses. The resulting data from each subject was then compared to published literature studies which provided minimal estimates of combined EPA/DHA/DPA levels in plasma lipid that were associated with recommended dietary intakes of LC omega-3 for better cardiovascular health and target plasma levels for cardiovascular protection.
The data revealed that 80.6 % of the population studied (ages 20 and over) had circulating plasma LC omega-3 levels that were below concentrations recommended for cardiovascular health. The low levels of LC omega-3 were somewhat more prevalent in the younger population sector aged 20-39 years (84.2 %) as compared to the older sector aged equal to or greater than 60 years (72.9 %). Almost all participants (95.7 %) had LC omega-3 levels which were below target for cardiovascular protection. The authors concluded that sub-optimal LC omega-3 levels are common amongst American adults which highlight the need for greater intakes of these fatty acids.
Dr. Holub's Comments:
The present study reporting a high prevalence of sub-optimal LC omega-3 levels in the circulation of adults in the United States is consistent with studies elsewhere in other countries. For example, an earlier Canadian study (Holub et al., Nutrition Journal, 8:58 (2009)) wherein 2053 blood samples were analyzed for the total omega-3 fatty acid levels in the serum phospholipid (biomarker) indicated that at least half would be in the ‘risk’ category for cardiovascular-disease related outcomes. These findings emphasize the importance of public educational programs directed at increasing dietary intakes of LC omega-3 fatty acids (from appropriate fish/seafood sources and enriched foods as well as quality supplements as needed) for health conditions where higher intakes of DHA/EPA have been found to be beneficial.