Comparing the Impact of Saturated Fatty Acids from Different Dairy Sources on LDL Particle Size Phenotype

Abstract

BackgroundLow‐density lipoproteins (LDL) constitute a heterogeneous class of lipoproteins among which small and dense LDL may be more atherogenic than large LDL particles, independent of cholesterol concentrations. The aim of this study was to examine how consumption of saturated fat (SFA) from different dairy sources modifies the LDL particle size phenotype compared with other dietary fats (monounsaturated ‐ MUFA and polyunsaturated fat‐ PUFA) and a low‐fat diet/high carbohydrate diet.MethodsA randomized crossover controlled trial was conducted in 92 men and women with abdominal obesity and relatively low HDL‐C. Subjects were assigned to sequences of 5 isoenergetic diets of 4 weeks each (Table): 1) a diet rich in SFA from cheese (CHEESE); a diet rich in SFA from butter (BUTTER); a diet rich in MUFA; a diet rich in PUFA and a low‐fat, high carbohydrate diet (CHO). All foods were provided to the participants during the experimental phases. Features of the LDL particle size phenotype (mean LDL particle size, proportion of small and large) were assessed by one dimension nondenaturing polyacrylamide gel electrophoresis.ResultsLDL particle size at baseline (mean±SD) in women was larger than in men (252.24±2.85 vs. 251.67±3.49, p=0.04), although differences were no longer significant after adjustment for waist circumference. The CHEESE diet had no significant impact on all phenotypic measures of LDL particle size compared with BUTTER, CHO, MUFA and PUFA. Consumption of the BUTTER diet significantly increased LDL mean size compared with CHO (p=0.021) and MUFA (p=0.005). The increase in mean LDL size with BUTTER was more apparent among individuals with small LDL particles at baseline than among those with large LDL (P treatment × baseline LDL size=0.047). There was no difference in the distribution of small and large LDL particles among diets.ConclusionsResults from this full‐feeding study suggest 1‐ that SFA from butter and cheese have similar effects on features of the LDL particle size phenotype, and 2‐ that consumption of SFA from butter may be associated with less atherogenic LDL particles. These data are partly consistent with the fact that consumption of cheese and butter are not associated with an increased risk of cardiovascular disease.Support or Funding InformationSource of Research Support : Dairy Research Cluster Initiative (Dairy Farmers of Canada, Agriculture and Agri‐Food Canada, the Canadian Dairy Network and the Canadian Dairy Commission). Macronutrient (% energy), calcium and sodium content of experimental diets CHEESE BUTTER MUFA PUFA CHO Lipids (%) 32.0 32.0 32.0 32.0 25.0 SFA (%) 12.6 12.4 5.8 5.8 5.8 MUFA (%) 12.5 12.3 19.6 12.6 12.6 PUFA (%) 4.8 4.8 4.8 11.5 4.8 Carbohydrates (%) 51.9 52.0 51.9 51.9 58.9 Proteins (%) 16.0 16.0 16.0 16.0 16.0 Calcium (mg/2500 kcal) 1261 811 812 812 842 Sodium (mg/2500 kcal) 2482 2480 2479 2479 2485 Fibers (g/2500kcal) 31 31 31 31 31