Curcumin potentiates cholesterol-lowering effects of phytosterols in hypercholesterolaemic individuals. A randomised controlled trial

• Published in: Metabolism, clinical and experimental Vol. 82; pp. 22 - 35
• Main Authors: Ferguson, Jessica J.A., Stojanovski, Elizabeth, MacDonald-Wicks, Lesley, Garg, Manohar L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2018
• Subjects: Anticholesteremic Agents - therapeutic use; Cardiovascular disease; Cholesterol; Cholesterol - blood; Curcumin; Curcumin - therapeutic use; Double-Blind Method; Drug Interactions; Female; Humans; Hypercholesterolemia; Hypercholesterolemia - blood; Hypercholesterolemia - drug therapy; Male; Middle Aged; Phytosterols; Phytosterols - therapeutic use; Treatment Outcome; Triglycerides - blood; RCT; PS; LDL-C; LXR; Cardiovascular disease; ACAT; HDL-C; HMG-CoA reductase; NPC1L1; LCn-3PUFA; Curcumin; CYP7A; CC; SREBP; PS-CC; TC:HDL; Phytosterols; Cholesterol; TC; CVD; HOMA-IR; TG; Hypercholesterolemia; PL; ATP; CHD
• ISSN: 0026-0495; 1532-8600
• DOI: 10.1016/j.metabol.2017.12.009

Dietary phytosterols (PS) are well-known hypocholesterolaemic agents. Curcumin elicits hypolipidaemic and anti-inflammatory effects in preclinical studies, however, consistent findings in humans are lacking. Concurrent PS and curcumin supplementation may exhibit enhanced hypocholesterolaemic and anti-inflammatory effects to optimise cardio-protection. The objective of this trial was to investigate the effects of dietary intervention with PS with or without curcumin on blood lipids (primary outcome) in hypercholesterolaemic individuals. A double-blinded, randomised, placebo-controlled, 2 × 2 factorial trial was conducted in hypercholesterolaemic individuals. Participants received either placebo (PL, no phytosterols or curcumin), phytosterols (PS, 2 g/d), curcumin (CC, 200 mg/d) or a combination of PS and curcumin (PS-CC, 2 g/d–200 mg/d respectively) for four weeks. Primary outcomes included fasting total cholesterol (TC), LDL-cholesterol, HDL-cholesterol, triglycerides (TG), TC-to-HDL-C ratio (TC:HDL-C). Secondary outcomes included anthropometrics and fasting blood glucose concentrations. Seventy participants with a mean (±SEM) fasting TC concentration of 6.57 ± 0.13 mmol/L completed the study (PL, n = 18; PS, n = 17; CC, n = 18; PS-CC, n = 17). PS and PS-CC supplementation significantly lowered TC, LDL-cholesterol and TC:HDL-C post-intervention (p < 0.05). Reductions from baseline in the PS group were 4.8% and 8.1% for TC and LDL-cholesterol respectively (p < 0.05). CC exhibited non-significant reduction (2.3% and 2.6%) in TC and LDL-C respectively, however, the PS-CC resulted in a greater reduction in TC (11.0%) and LDL-cholesterol (14.4%) than either of the treatments alone (p < 0.0001). The reduction in the PS-CC treatment was significantly greater compared to those for CC (p < 0.05) or PL (p < 0.01) alone. Plasma HDL-cholesterol and TG concentrations remained unchanged across all groups. No adverse side effects were reported. The addition of curcumin to phytosterol therapy provides a complementary cholesterol-lowering effect that is larger than phytosterol therapy alone. Implications of these findings include the development of a single functional food containing both the active ingredients for enhanced lipid-lowering and compliance in hypercholesterolaemic individuals. ANZCTR identifier: 1261500095650