title: The -308 G/A polymorphism of the tumour necrosis factor-α gene modifies the association between saturated fat intake and serum total cholesterol levels in white South African women.
abstract: This study explored interactions between dietary fat intake and the tumour necrosis factor-α gene (TNFA) -308 G/A polymorphism on serum lipids in white South African (SA) women. Normal-weight (N = 88) and obese (N = 60) white SA women underwent measurements of body composition, fat distribution, fasting serum lipids, glucose, insulin concentrations and dietary intake. Subjects were genotyped for the functional -308 G/A polymorphism within the TNFA gene. There were no significant differences in the genotype or allele frequencies between groups, and no significant genotype associations were found for body fatness or distribution, or serum lipid concentrations. However, there was a significant interaction effect between dietary saturated fat (SFA) intake (%E) and TNFA -308 genotypes on serum total cholesterol concentrations (P = 0.047). With increasing SFA intake (%E), serum total cholesterol levels decreased for the GG genotype and increased for the GA plus AA genotypes. The TNFA -308 G/A polymorphism appears to modify the relationship between dietary fat intake and serum total cholesterol concentrations in white SA women.
authors.affiliation: UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Newlands, Cape Town, South Africa.
authors.forename: Yael T
authors.initials: YT
authors.lastname: Joffe
authors.forename: Lize
authors.initials: L
authors.lastname: van der Merwe
authors.forename: Malcolm
authors.initials: M
authors.lastname: Collins
authors.forename: Madelaine
authors.initials: M
authors.lastname: Carstens
authors.forename: Juliet
authors.initials: J
authors.lastname: Evans
authors.forename: Estelle V
authors.initials: EV
authors.lastname: Lambert
authors.forename: Julia H
authors.initials: JH
authors.lastname: Goedecke