Estimation and predictors of the Omega-3 Index in the UK Biobank

authored by
Jan Philipp Schuchardt, Nathan Tintle, Jason Westra, William S. Harris

Information on the Omega-3 Index (O3I) in the United Kingdom (UK) is scarce. The UK-Biobank (UKBB) contains data on total plasma n3-PUFA% and DHA% measured by NMR. The aim of our study was to create an equation to estimate the O3I (eO3I) from these data. We first performed an inter-laboratory experiment with 250 random blood samples in which the O3I was measured in erythrocytes by GC, and total n3 % and DHA% were measured in plasma by NMR. The best predictor of eO3I included both DHA% and a derived metric, the total n3 %-DHA%. Together these explained 65 % of the variability (r = 0·832, P < 0·0001). We then estimated the O3I in 117 108 UKBB subjects and correlated it with demographic and lifestyle variables in multivariable-adjusted models. The mean eO3I was 5·58 % (sd 2·35 %) in this UKBB cohort. Several predictors were significantly correlated with eO3I (all P < 0·0001). In general order of impact and with directionality (-, inverse and +, direct): oily-fish consumption (+), fish oil supplement use (+), female sex (+), older age (+), alcohol use (+), smoking (-), higher waist circumference and BMI (-), lower socioeconomic status and less education (-). Only 20·5 % of eO3I variability could be explained by predictors investigated, and oily fish consumption accounted for 7·0 % of that. With the availability of the eO3I in the UKBB cohort, we will be in a position to link risk for a variety of diseases with this commonly used and well-documented marker of n3-PUFA biostatus.

Institute of Food Science and Human Nutrition
Nutrition Physiology and Human Nutrition Section
External Organisation(s)
Fatty Acid Research Institute (FARI)
University of Illinois at Chicago
University of South Dakota
British Journal of Nutrition
No. of pages
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Medicine (miscellaneous), Nutrition and Dietetics
Sustainable Development Goals
SDG 3 - Good Health and Well-being
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