Abstract
In this study we compared the effects of a low-fat, high-carbohydrate (LFHC) diet at two levels of polyunsaturated fatty acids on plasma lipids of 20 patients affected by familial endogenous hypertriglyceridemia. During the intervention period the proportion of dietary energy derived from fat was reduced from about 45% to 20% in all the subjects. Ten patients (group I) consumed a LFHC diet with a polyunsaturated to saturated fat (P/S) ratio of 0.4, while the other 10 patients (group II) had a diet with a P/S ratio of 1–7. During the intervention period we observed a significant decrease of total plasma triglycerides and cholesterol in both groups. In spite of the different P/S ratio, the decrease of total triglycerides and cholesterol was superimposable in the two groups. The fall in plasma triglycerides and cholesterol was due only to the decrease in very low density lipoproteins (VLDL). On the contrary, low density lipoproteins (LDL) cholesterol was unchanged in both groups. Finally, during the intervention period we observed an increase of high density lipoproteins (HDL) cholesterol only in group I while it did not vary in group II. During the intervention period the HDL to LDL cholesterol ratio increased significantly only in group I while it did not vary in group II. The increase of HDL cholesterol levels observed in group I was due mainly to the rise of HDL2 cholesterol concentrations. The results show that when the intake of fat, and in particular, of saturates is reduced the effect of different amounts of polyunsaturates or monounsaturates on plasma triglycerides and cholesterol subfraction levels seems to be variable.