Fat restriction alters the composition of apolipoprotein B-100 containing very low-density lipoproteins in humans.

We investigated effects of fat saturation and fat restriction on very low-density apolipoproteins (VLDL) including the isoforms. Normolipidemic women (22) were given a reference diet, a polyunsaturated diet, and a low-fat, polyunsaturated diet for 6 wk each. The polyunsaturated diet decreased cholesterol and apolipoprotein B levels in VLDL (-33.1% and -23.8%) and in LDL (-13.5% and -8.8%) without affecting HDL. The low-fat, polyunsaturated diet resulted in a reincrease of VLDL triglycerides, but not of VLDL cholesterol. Concentration of VLDL apolipoprotein B fell further (-41.6%). All VLDL apolipoprotein B was in the B-100 region. Though the apolipoprotein E phenotype (E-3/E-3) remained constant, a shift to more (nonsialated) apolipoprotein E isoforms could be confirmed, resulting in an increased apolipoprotein E-3 to apolipoprotein E-2 area ratio (+30.6%). This study indicates that restriction of dietary-fat intake alters the composition of apolipoprotein B-100 containing VLDL that may be favorable for atherogenesis.