Change in plasma phospholipid fatty acids over 13 years and determinants of change: EPIC‐Norfolk Study

Abstract

We aimed to investigate the changes in 27 individual plasma phospholipid fatty acids and fatty acid groups over time, and examine potential determinants of these changes. In the European Prospective Investigation of Cancer (EPIC)‐Norfolk study, plasma phospholipid fatty acids (%mol) were profiled in 722 participants at three time‐points (1993–1997, 1998–2000, 2004–2011) over approximately 13 years. Linear mixed‐effects models were used to estimate 1) the annual change in individual plasma fatty acids and fatty acid groups, adjusting for potential confounders and 2) associations of change in dietary or lifestyle factors with change in 8 pre‐specified plasma fatty acid groups, with mutual adjustment for dietary/lifestyle factors and other confounders. The pre‐specified fatty acid groups were odd‐chain saturated fatty acids (SFA, C15:0+C17:0), even‐chain SFAs (C14:0+C16:0+C18:0), very‐long‐chain SFAs (C20:0+C22:0+C23:0+C24:0), marine n‐3 polyunsaturated fatty acids (PUFA, C20:5n3+C22:5n3+C22:6n3), plant n‐3 PUFA (C18:3n3), n‐6 PUFAs, monounsaturated fatty acids (MUFAs) and trans fatty acids. There were significant annual decreases in levels of odd‐chain SFAs (−0.63%, 95%CI: −0.73%, −0.52%), even‐chain SFAs (−0.05%, 95%CI: −0.06%, −0.03%), n‐6 PUFAs (−0.25%, 95%CI: −0.29%, −0.20%) and trans fatty acids (−7.84%, 95%CI: −8.07%, −7.61%), significant annual increases in marine n‐3 PUFAs (1.28%, 95%CI: 1.11%, 1.44%) and MUFAs (0.45%, 95%CI: 0.37%, 0.54%), and no significant changes in very‐long‐chain SFAs or plant n‐3 PUFA. Change in each plasma fatty acid group was associated with change in intake of various food groups; for example, 100g/day increase of change in fatty fish intake was associated with a 5.26% (95% CI: 1.26%, 9.42%) annual increase in plasma marine n‐3 PUFAs. Change in BMI or physical activity was not associated with change in any fatty acid group. The annual changes observed cannot be explained by diet alone and therefore suggest that aging processes have a discernible effect on fatty acids of the plasma phospholipid fraction. In conclusion, most individual plasma fatty acids and fatty acid groups changed over time. These changes were partially explained by changes in aspects of diet.Support or Funding InformationMedical Research Council Epidemiology Unit MC_UU_12015/1 and MC_UU_12015/5; Medical Research Council Human Nutrition Research MC_UP_A090_1006; Cambridge Lipidomics Biomarker Research Initiative G0800783; Cambridge Initiative‐Nutrition (RG71466, SJAH/004), Marie Skłodowska‐Curie Fellowships (701708, RG82205, SJAI/051),