Dietary Nutrients and Plasma n -3, n -6, Saturated and Monounsaturated Fatty Acids

The aim of this study was to determine the relationship between dietary nutrients and plasma fatty acids in a cross-sectional survey of the general population. A sample of 306 men and women aged 55-74 years (half of whom had clinical evidence of arterial disease) completed a food frequency questionnaire and had a blood sample taken for the estimation of plasma fatty acid concentrations. Several dietary nutrients were found to correlate with the plasma fatty acids. Dietary saturated fat was positively correlated with plasma oleic acid, but inversely related to the n -6 fatty acids. Dietary linoleic acid (LA) and a -tocopherol were positively correlated with plasma LA and its metabolites, but inversely associated with palmitic and oleic acids, and with a -linolenic (ALA) and eicosapentaenoic acids (EPAs). Vitamin C showed positive correlations with LA and its metabolites, but negative associations with oleic acid. b -Carotene was inversely associated with oleic acid, and positively associated with LA. Alcohol intake was positively associated with plasma arachidonic acid (AA), docosahexaenoic acid (DHA) and EPAs which are protective against atherosclerosis. Both dietary vegetable and cereal fibre showed negative correlations with oleic acid and positive associations with LA, but only vegetable fibre was associated with AA, EPAs and DHA. These findings therefore demonstrate that several dietary nutrients known to be associated with less cardiovascular disease are correlated with higher levels of polyunsaturated fatty acids, which may therefore be acting as mediators in the prevention of vascular disease.