New results show guggulipid extract fails to lower cholesterol
cholesterol-lowering drugs in Asia, has turned out to be no more
effective than a placebo in clinical trials, report researchers in
the latest edition of JAMA.
A guggulipid extract, used as an alternative to cholesterol-lowering drugs in Asia, has turned out to be no more effective than a placebo in clinical trials, report researchers in yesterday's Journal of the American Medical Association (JAMA).
"We found that the guggulipid product did not lower the level of LDL-C (low density lipoprotein cholesterol) in our trial participants, but actually raised LDL-C slightly," said Dr Philippe O. Szapary, assistant professor of Medicine at the University of Pennsylvania School of Medicine and principal author of the study.
Recently, guggulsterones, the bioactive compounds of guggul, have been shown to be potent antagonists of two nuclear hormone receptors involved in cholesterol metabolism, establishing a plausible mechanism of action for the hypolipidemic effects of these extracts. However, there is little data on the use of guggul extracts in Western populations.
The randomised, double-blind, eight-week study included 103 healthy adults with raised cholesterol levels who were divided into three groups. One group was given a standard dose (1000mg) of a standardized guggul extract (guggulipid, containing 2.5 per cent guggulsterones) three times daily; a second group was given a high dose of 2,000 mg of the extract; and the third group was given the placebo. All continued eating typical Western diets.
"We found LDL-C increased by 4 per cent in the standard-dose group and 5 per cent in the high-dose group. At the same time, it decreased by 5 per cent in the placebo group," Szapary said. Low-density lipoprotein can lead to heart disease by accumulating on arterial walls.
The researchers also reported that a small subset of patients taking the herb developed a rash "indicating they were experiencing hypersensitivity drug reactions". The rash disappeared when they stopped taking the supplement.
"Our findings do not support the use of guggulipid to control LDL-C in the general population," Szapary concluded. He added that the results "strengthen our belief that dietary supplements need to be studied in a rigorous way, to test both their safety and their efficacy".
Szapary is extending the study to investigate further the effects of guggulipid on triglycerides, or blood fats, and inflammation, both of which appeared to be more responsive than cholesterol to the effects of the herb in the clinical study.
Guggulipid, a substance derived from one of the fabled myrrh plants of the Middle East, has a 2,600-year tradition in traditional medicine. Indian practitioners of ayuvedic medicine have used the herb in holistic regimens combining meditation, yoga and diet to treat obesity, atherosclerosis, high cholesterol and arthritis.
The study was partly funded by Sabinsa, a US manufacturer of a guggulipid extract product.
