title: Effects of low fat diets differing in degree of fat unsaturation on plasma lipids, lipoproteins, and apolipoproteins in adult men.
abstract: The effects of two low fat diets with differing ratios of polyunsaturated to saturated fatty acids (P/S) on blood lipids, lipoproteins (LP), and apolipoproteins (Apo) were studied in 23 adult men, 30-60 years old, using a crossover design. Both test diets had 25% fat calories with either a P/S of 0.3 (Diet 1) or a P/S of 1.0 (Diet 2) and equivalent amounts of cholesterol. The study consisted of four periods: a 5-week prestudy on self-selected diet (SS), two 6-week test diet periods followed by a second 5-week post-study period on the SS diet. When compared with the SS diet, Diet 2 lowered the mean plasma total cholesterol (TC) by about 20% (P less than 0.01). Low density lipoprotein (LDL) cholesterol was also decreased by about 18% by Diet 2 (P less than 0.01). The high P/S diet did not cause a change in total cholesterol in the high density lipoprotein (HDL) subclass2 (HDL2) when compared to the SS diet. Levels of triglycerides (TG) were slightly reduced in HDL2 but showed a greater reduction in HDL3 in both diets. Phospholipids (PL) were significantly reduced in HDL2 and in HDL3, but the reduction in HDL3 PL was not statistically significant. Apo A-I levels were not changed by either diet when compared with the SS diet, but Apo A-II levels of HDL2 and HDL3 were significantly decreased by the low fat diets, and there was no P/S effect. No other consistent changes in apoprotein levels occurred. Our data suggest that, in men with normal lipid levels, practical dietary changes involving a moderate increase in P/S from 0.3 to 1.0 in a low fat, low cholesterol diet do influence lipoprotein composition and apoprotein distribution in a short time. The reduction in cholesterol in total lipid composition and in LDL lipids which accompanied the reduction of dietary fat and cholesterol are considered to be beneficial.
authors.affiliation: USDA, BHNRC, Maryland 20705.
authors.forename: J T
authors.initials: JT
authors.lastname: Judd
authors.forename: S Y
authors.initials: SY
authors.lastname: Oh
authors.forename: B
authors.initials: B
authors.lastname: Hennig
authors.forename: J
authors.initials: J
authors.lastname: Dupont
authors.forename: M W
authors.initials: MW
authors.lastname: Marshall
mesh_terms: D000328:Adult; D001053:Apolipoproteins / Q000097:blood*; D004041:Dietary Fats / Q000008:administration & dosage*; D004734:Energy Metabolism; D005224:Fats, Unsaturated / Q000008:administration & dosage*; D006801:Humans; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged
chemical_list: D001053:Apolipoproteins; D004041:Dietary Fats; D005224:Fats, Unsaturated; D008055:Lipids; D008074:Lipoproteins; D008077:Lipoproteins, LDL