Time dependent effects of n-3 supplementation for eight months on erythrocyte phospholipid fatty acid composition

Long chain polyunsaturated fatty acids (LCPUFAs) play an important role in maintaining health conditions. LCPUFAs are mainly present in cell membrane phospholipids. their release by specific enzymes results in the synthesis of biofunctional lipids. In order to avoid misregulation of specific pathways the ratio between the two main products of LCPUFA metabolism, i.e. arachidonic (AA) and eicosapentaenoic acid (EPA) should not exceed 5:1 as a maximum. due to changes in industrialized countries diet this value has been reported to be much higher. In a previous work, we described and validated for total blood fatty acid assays, a rapid method suitable for large scale population studies, and we have verified a possible correlation between total N-6/N-3 ratio and AA/EPA ratio in RBC phospholipids and in whole blood total lipids. 1.432 healthy volunteers and patients with various pathologies were recruited and categorised according to their age, sex and any existing pathologies. Our results indicate that AA/EPA ratio is a more sensitive and reliable index for determining changes in total blood fatty acids; moreover, it is correlated with the ratio observed in phospholipid extracted from RBC. in this study, we try to correlate, after a prolonged supplementation with a known amount of EPA and DHA, the values found in blood with those in RBC membrane phospholipids to evaluate the real incorporation of the supplement and the distribution of the fatty acids in the single phospholipid species.