Nutritional aspects of trans unsaturated fatty acids

Abstract

Dietary trans unsaturated fatty acids from hydrogenated vegetable and fish oils have been shown to raise plasma low density lipoprotein cholesterol and lower high density lipoprotein cholesterol levels at 10%, 6% and 3% of energy intake. As trans fatty acid intake has not been previously assessed in Ireland a food frequency questionnaire (FFQ) was developed to assess fat intake with particular focus on trans fatty acids. A nutrient database was developed which included the fatty acid and total trans fatty acid composition of foods (measured by gas chromatography and infra-red spectroscopy) which are sources of fat in the Irish diet. The FFQ was used to assess fat intake in 105 healthy volunteers and was validated by comparison with results obtained in the same population using the diet history method. In addition the linoleic acid and total trans fatty acid intake was assessed by gas chromatographic analysis of adipose tissue biopsies taken from the study group and this provided additional validation of the mean TUFA intake assessed by the FFQ. Mean TUFA intake assessed by the FFQ was 5.4 g/day (2% energy) although intakes ranged from 0.3-26 g/day.