According to the American Heart Association, about 40 million American adults have high cholesterol, or ]]>hypercholesterolemia]]> , which is defined as having total blood cholesterol values of 200 milligrams per deciliter (mg/dL) [5.18 millimole per liter (mmol/L)] and higher. High cholesterol is known to be a risk factor for cardiovascular disease. Each year, more than one million Americans have heart attacks, and about a half million people die from ]]>heart disease]]> .

Dietary supplements made of herbal extracts from Commiphora mukul ( ]]>guggul]]> ) have been widely used, particularly in Asia, as cholesterol-lowering agents. Recent research has suggested a plausible mechanism of action for the effects of guggul extract (guggulipid). Yet, little is known about the safety or efficacy of this herb.

Researchers set out to investigate whether guggulipid could safely reduce cholesterol levels in healthy adults with ]]>hyperlipidemia]]> (elevated concentrations of cholesterol and other lipids in the blood) who eat a typical Western diet. The results, which are published in the August 13, 2003 issue of the Journal of the American Medical Association (JAMA), indicate that neither a commonly used dose nor a high dose of guggulipid improves levels of cholesterol over the short term, and might in fact raise levels of LDL-cholesterol (the “bad” kind).

About the Study

The researchers randomized 103 adults to one of three groups: placebo, standard-dose guggulipid (SDG) of 1,000 milligrams (mg), and high-dose guggulipid (HDG) of 2,000 mg—taken three times daily with meals for eight weeks. Participants were told to maintain their usual dietary habits. The study was conducted from March 2000 through August 2001.

At the outset, participants were required to have an LDL of 130-200 mg/dL (3.37-5.18 mmol/L) and fasting triglyceride levels of less than 400 mg/dL (4.52 mmol/L). They were excluded if they had a history of cardiovascular disease, diabetes, untreated thyroid disorder, liver function abnormalities, or renal insufficiency.

Study assessments took place at baseline, four weeks, and eight weeks. At each visit, participants were weighed, had vital signs measured, were asked about adverse events and changes in medications, and had blood samples obtained for analysis.

The Findings

Levels of LDL-cholesterol increased significantly by 4% in the SDG group and by 5% in the HDG group, while they decreased by 5% in the placebo group. There were no significant changes in levels of HDL-cholesterol (the “good” kind) or triglycerides. Additionally, no effect was seen on total cholesterol/HDL or LDL/HDL ratios. However, in those participants who had a high baseline level of LDL (160 mg/dL (4.14 mmol/L) or greater), there was a significant decrease of triglycerides in both guggulipid groups. And, small but non-significant decreases were seen in levels of other substances (lipoprotein a and c-reactive protein) thought to play a role in cardiovascular disease.

In terms of safety, guggulipid was generally well tolerated and did not appear to adversely affect the kidneys or liver. However, six participants developed a hypersensitivity drug rash associated with itching, which in five of the six cases, led to dropout from the study.

An important limitation of this study is that the researchers did not recommend a specific diet. Although there were no statistically significant changes in weight or dietary consumption of fat, cholesterol, or fiber among the participants by the end of the trial, it is possible that unforeseen aspects of participants’ diet influenced the results. In addition, patients who take other cholesterol-lowering medications and supplements in the real world are strongly advised to also lower their intake of cholesterol.

How Does This Affect You?

This study suggests that dietary supplements containing guggulipid do little to improve cholesterol levels and may even cause a hypersensitivity drug reaction in certain people. But the researchers also found a significant reduction of triglycerides in both the SDG and HDG groups among participants with high LDL-cholesterol levels, as well as borderline significant reductions in the level of other cardiovascular health markers. It could be that individuals with high triglycerides and LDL-cholesterol may benefit from supplementing their low-fat, high-fiber diet with guggulipid.

Because the study lasted only eight weeks, researchers could not assess whether guggulipid might improve or worsen a person’s chances of developing cardiovascular disease in the long-term, which is really the point. And, although the amount of guggulipid used in this study was relatively high, it is possible that higher doses are needed to have a clinically important effect.

While this study does not seem to support the use of guggulipid for the modification of lipids and other cardiovascular risk factors, it may be too soon to give up on this treatment. Meanwhile, try lowering your cholesterol by eating a healthful diet and getting plenty of exercise. If you have high blood cholesterol, talk to your doctor about what’s right for you.