['To evaluate whether the relationship between dietary composition and plasma lipid levels is genetically determined.', 'We have evaluated the influence of common apolipoprotein A5 (APOA5) variants (T-1131 > C, Ser19 > Trp and Val153 > Met) on plasma lipid concentrations in 117 males for whom dietary composition markedly changed and total cholesterol decreased (from 6.21 +/- 1.31 mmol/L in 1988 to 5.43 +/- 1.06 mmol/L in 1996) over an 8 year follow-up study.', 'APOA5 T-1131 > C and Val153 > Met variants did not influence the change in lipid measures over time. In Ser/Ser19 homozygotes, the plasma cholesterol was relatively stable over the years (6.1 +/- 1.2 mmol/L in 1988 and 5.6 +/- 1.0 mmol/L in 1996, -8%, P < 0.01). In contrast, in the Trp19 carriers, the decrease of the plasma cholesterol was more than 20% (6.5 +/- 1.6 mmol/L in 1988 and 5.1 +/- 1.0 mmol/L in 1996) (P < 0.001). The difference of the changes is significant (8% vs. 20%, P < 0.005). Changes in other analyzed lipid parameters have not been significantly associated with APOA5 variants.'] Does aPOA5 variant Ser19Trp influence a decrease of the total cholesterol in a male 8 year cohort?