薬理と治療

Abstract

Background Garlic has been widely shown in animal and human studies to be hypolipidemic, although the impact of garlic on human lipid parameters has become more and more controversial. In Japan there is a unique type of traditional health food known as“kurozu-garlic（KG）”that has been made from kurozu（unrefined black rice vinegar）and garlic combination through an acetic acid fermentation process. Using a representative commercial product of KG diet as the study diet, the present clinical trial was undertaken to investigate the effect of KG on serum lipid profiles, particularly serum total cholesterol（TC）and low-density lipoprotein cholesterol（LDL-C）, in volunteer subjects with prehypercholesterolemia and mild-to-moderate hypercholesterolemia. Methods A randomized, double-blind, placebo-controlled intervention study was conducted in 64 subjects with serum LDL-C ranging from 120 to 180 mg╱dL at baseline. Each subject was given KG diet capsules containing 200 mg of KG（KG group）or matching placebo capsules（placebo group）daily for 12 weeks. Blood samples were taken from all subjects to measure serum lipid parameters at weeks 0 （baseline）, 4, 8, and 12. Results Intervention with the KG diet resulted in a moderate but statistically significant decrease in TC and LDL-C levels that was observed at 4, 8, and 12 weeks of active intervention. By the end of the study, TC and LDL-C levels in KG group had fallen by 6.4 and 6.2％ （both: P＜0.01）, respectively, from baseline, and between-group differences in changes from baseline of TC and LDL︱C levels were significant at week 4（P＝0.031 and P＜0.01, respectively）. A similar hypocholesterolemic effect of the KG diet consumption was also observed when substudy analyses were performed on the subjects with relatively low LDL-C levels at baseline（120︱159 mg╱dL）referred as the subpopulation L. In KG group of this subpopulation, there were significant reductions in TC and LDL-C levels from baseline at weeks 4, 8, and 12（P＜0.01 or＜0.05）with a significant difference from placebo group in changes from baseline of LDL-C values at week 4（P＝0.038）. Conclusion Although the results are not definitive, the present study showed that the KG diet intake may have the potential for improving serum levels of TC and LDL-C in the subject population comprising prehypercholesterolemic and mild-to-moderate hypercholesterolemic subjects（LDL-C levels, 120-180 mg╱dL）, as well as in the subpopulation whose LDL-C levels are between 120 and 159 mg╱dL.