High serum n6 fatty acid proportion is associated with lowered LDL oxidation and inflammation: The Cardiovascular Risk in Young Finns Study

Abstract

The intake of polyunsaturated fatty acids (PUFAs) is generally linked with a reduced cardiovascular disease (CVD) risk, but an elevated n6PUFA intake, without simultaneous n3PUFA supply, may elevate the risk. PUFAs are suspected as being easily oxidized and have a potential role in lipoprotein oxidation and inflammation. Saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) are resistant to oxidation. However, in a Western diet, their most important source is red meat, a food stuff rich in heme iron which can catalyze oxidative reactions. Therefore, different serum fatty acid (FA) proportions (free + esterified) were correlated with the status of low-density lipoprotein (LDL) oxidation in vivo (conjugated dienes = oxLDLlipids and antibody-based oxidized proteins = oxLDLprot) and inflammation (serum CRP) in 2196 Finnish subjects (age: 24–39 years) using CVD risk factor-adjusted linear regression models. High n6PUFA, PUFA/SFA and n6/n3 ratios, and low SFA and MUFA were all associated with reduced levels of oxLDLlipids, oxLDLprot, and CRP. These findings at the population level suggest that PUFAs are negatively and SFAs and MUFAs positively related with LDL oxidation and inflammation; these conclusions are in line with previous observations linking PUFAs, particularly n6PUFAs, with lower CVD risk, and SFAs with increased risk.

Keywords::

• atherosclerosis
• degree of fatty acid unsaturation
• lipid peroxidation
• oxidative stress
• polyunsaturated fatty acid

Acknowledgments

We thank Irina Lisinen and Ville Aalto for data management.

Declaration of interest

The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

This work was financially supported by the Academy of Finland: grants 126925, 121584, 124282, 129378, 117797, and 41071, the Social Insurance Institution of Finland, Kuopio, Tampere and Turku University Hospital Medical Funds (grant 9N035 for T.L.), Juho Vainio Foundation, Paavo Nurmi Foundation, Finnish Foundation of Cardiovascular Research (T.L., O.T.R.) and Finnish Cultural Foundation, Sigrid Juselius Foundation, Tampere Tuberculosis Foundation, Emil Aaltonen Foundation (T.L.) and by the Yrjö Jahnsson foundation (J.E.K).