Background: Guggul, herbal extracts from resin of the Commiphora mukul tree, is widely used in Asia as cholesterol-lowering agents from the Indian traditional system of medicine. Their popularity is increasing in the US and Western Europe. Guggulsterones, the presumed bioactive compounds of guggul, may antagonise two nuclear hormone receptors involved in cholesterol metabolism, which is a possible explanation for hypolipidemic effects of these extracts. However, publications of efficacy data on the use of guggul extracts in Western populations are scarce.
Objective: To study the efficacy of guggul on blood lipids in healthy adults with moderately increased cholesterol.
Methods: Double-blind, randomised, placebo-controlled trial in Norwegian general practice. 43 women and men, age 27 to 70, with moderately increased cholesterol, randomised to use 4 capsules daily, either of guggul or placebo, for 12 weeks.
Outcome measures: Mean change in levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglycerides, high-density lipoprotein cholesterol (HDL-C) and total cholesterol/HDL-C-ratio compared with baseline. Levels were measured at baseline, after 6 and 12 weeks. In addition, unexpected effects and adverse events were recorded.
Results: Three of the 43 participants originally randomised, were excluded: one because of concurrent disease, another because he developed a skin rash, the third discontinued for reasons not related to the trial. In addition, incomplete laboratory data were gathered for six participants. Because of technical mistakes, these measurements where lost. 34 participants accomplished the trial (18-gugull, 16-pacebo), with complete laboratory data.
After 12 weeks, mean levels of total cholesterol and HDL-C in the active group were significantly reduced (respectively 3,4% and 6,3%) compared with the placebo group. However, the mean levels of LDL-C, triglycerides, and total cholesterol/HDL-C-ratio between the two groups did not change significantly. The guggul capsules were generally well tolerated, but seven participants treated with guggul reported mild gastrointestinal discomfort, compared with one in the placebo group. One participant treated with guggul developed a skin rash, two reported thyroid related problems.
Conclusions: This randomised placebo-controlled trial did not altogether show guggul to improve levels of blood lipids in adults with moderately increased cholesterol: levels of total cholesterol and HDL-C were significantly reduced. However, total cholesterol/HDL-C-ratio did not change significantly.
We can not recommend use of guggul on this indication. Further study is necessary before a definitive conclusion on the efficacy and safety of guggul can be reached.