Background and aims: Sphingolipids (SL) are important components of the milk fat globule membrane (MFGM) found in buttermilk. While studies in animal models suggest that dietary SL may have cholesterol-lowering properties, data in human are lacking. The aim of this study was to investigate the impact of buttermilk consumption on plasma lipids and surrogate markers of cholesterol (C) homeostasis in humans.
Methods and results: Men and women (n = 34) with serum LDL-C <5.0 mmol/L at screening (mean LDL-C = 3.8 mmol/L) were recruited in this double-blinded randomized crossover placebo controlled study. Their diets were supplemented with 45 g/d of buttermilk and with 45 g/d of a macro/micronutrient matched placebo (4 weeks each in random order). Serum lipid concentrations and surrogate markers of cholesterol homeostasis were measured post diet and compared using mixed models for repeated measures. Consumption of buttermilk led to reduction in serum cholesterol (-3.1%, P = 0.019), LDL-C (-3.1%, P = 0.057) and triacylglycerol (-10.7%, P = 0.007). Buttermilk consumption increased plasma lathosterol concentrations (+12.1%, P = 0.001), but multiple regression analysis indicated that variations in β-sitosterol concentrations (P = 0.002) were the only significant predictor of the LDL-C response to buttermilk consumption.
Conclusion: Buttermilk consumption may be associated with reduced cholesterol concentrations in men and women, primarily through inhibition of intestinal absorption of cholesterol.
Registration number: This trial is registered at clinicaltrials.gov as NCT01248026.
Keywords: ApoB; BMI; Buttermilk; C; C-reactive protein; CDV; CHD; CRP; Cholesterol homeostasis; FA; FFQ; FSH; MFGM; Milk polar lipids; PCSK9; Plasma lipids; SFA; SL; SM; Sphingomyelin; TG; apoliporotein-B; body mass index; cardiovascular disease; cholesterol; coronary heart disease; fatty acids; follicle-stimulating hormone; food-frequency questionnaire; milk fat globule membrane; protein convertase subtilisin kexin-9; saturated fatty acids; sphingolipids; sphingomyelin; triacylglycerol.
© 2013 Elsevier B.V. All rights reserved.