More research needed on this Indian remedy
The Irish Times
Health Supplement, p. 13
5 May 2009
DOES IT WORK? Guggul and high cholesterol
THE GUGGUL tree is native to India and produces a resin that has been used in traditional Indian (or Ayurvedic) medicine since at least 600BC. The resin is similar to biblical myrrh, used in anointing oils and incense. Myrrh comes from a different shrub that is closely related to the guggul tree. The bark of the guggul tree is cut, which results in a yellowish gum “bleeding” from the incision. After this dries and hardens, the resin is collected for further processing.
In 1987 an extract of the resin, called guggulipid, was officially approved in India as a lipid-lowering agent. This led to American and European interest in the product, leading to the marketing of guggulipid as a dietary supplement. It is often included in multiherb products that are said to give more healthy blood lipid levels.
Evidence from studies
Numerous laboratory studies have identified several compounds in guggul which affect blood lipids. Some compounds also have antioxidant effects, which are beneficial in reducing some of the damaging effects of blood lipids.
Cholesterol and other lipid levels are reported in different ways. Total triglyceride level measures all the lipids in the blood. Total cholesterol includes high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). A dietary supplement, or other change, is beneficial if it leads to reductions in total triglycerides, total cholesterol or LDL-C levels and increases in HDL-C levels.
A small number of studies were conducted in India in the 1970s and 1980s. Most, but not all, of these studies found beneficial effects when people used guggulipid for up to four months. These included reductions in total triglycerides, total cholesterol and LDL-C levels and increases in HDL-C levels. However, these studies had small numbers of participants and only two were high-quality randomised, double-blind studies. Nonetheless, they were deemed sufficient to approve guggulipid in India.
With the increased interest in guggul, the first randomised, controlled trial in a western population was published in 2003. In contrast to the Asian studies, this US study found an almost 10 per cent increase in LDL-C levels, with no significant changes in any of the other measurements. This problematic change had been found in some patients in India, although not in the research studies.
The second controlled trial of guggulipid in a western population was published in 2009. This study was conducted in Norway and found reductions in total cholesterol and HDL-C levels. The other lipid levels were not significantly changed. Thus, beneficial effects have not been found for European and American participants.
Guggulipid does have a number of adverse effects, though they tend to be relatively mild. Up to about one-third of people get various gastrointestinal side effects, including diarrhoea, nausea and vomiting. Almost three-quarters of the participants in one study reported getting headaches.
Mild skin reactions also occur regularly, though they tend to disappear within a week of using the products. Very occasionally, more severe reactions have occurred, though once guggulipid was stopped, the symptoms resolved themselves.
Laboratory research supports the presence of ingredients which may produce beneficial effects on blood lipid levels. The differences between the results obtained in earlier Indian research and more recent western research could be due to a number of factors. One common proposal is that guggul combined with an Indian diet is more beneficial than when taken by people on western diets. Also, the precise composition of the products may have varied. An independent evaluation of guggul products on the US market found that only one of the five analysed contained the amount of guggulipid stated on its label. Given all these variables, more research is needed before we can know if guggulipid would have beneficial effects for people eating an average Irish diet.