The relationship between the phospholipid fatty acid composition of red blood cells, plasma lipids, and apolipoproteins.

This study examined the relationship between the fatty acid composition of red blood cell phospholipids and lipid markers of atherosclerotic risk in an urban male population aged 45 to 66 years. There was a surprisingly significant positive association between the docosahexaenoic acid ([DHA] 22:6n-3) content of erythrocyte phospholipids and the following risk markers: plasma cholesterol (P < .01), low-density lipoprotein (LDL) cholesterol (P < .01), apolipoprotein (apo) B (P < .05), and apo B-containing lipoprotein particles (P < .05) recognized by a monoclonal antibody (LpBL3). On the other hand, phospholipid alpha-linolenate was positively correlated with apo A-I and high-density lipoprotein (HDL) cholesterol levels (P < .05), while arachidonate showed an inverse relationship with plasma cholesterol (P < .05). There was a negative association between palmitoleic acid and apo B (P < .01) and LpBL3 (P < .001); the latter showed a negative association with stearic acid (P < .001). These interesting findings emphasize the beneficial effect on atherosclerotic risk markers of dietary n-6 polyunsaturated and monounsaturated fatty acids, and suggest that long-chain n-3 polyunsaturated fatty acids (DHA) could have an adverse effect on some of the lipid risk markers.