Herbal Products for High Blood Cholesterol

Although many herbal products are promoted for their cholesterol-lowering properties, in general, conclusive scientific evidence supporting the safety and efficacy of herbal products is still lacking.

In June 2003, researchers from the United Kingdom published a study in The Journal of Family Practice (Volume 52; No.6, pp. 468-478) in which they summarized their findings of a systematic review randomized clinical trials of select herbal products that are promoted for their cholesterol-lowering properties. In general, the authors found that there is some supporting evidence from randomized clinical trials that the following herbal products can lower total serum cholesterol by 10% to 33%:

  • Arjun
  • Artichoke
  • Eggplant
  • Fenugreek
  • Guggul
  • Holy basil
  • Red yeast rice
  • Yarrow

Some of these herbal substances appear to lower LDL ("bad") cholesterol while also increasing levels of HDL ("good") cholesterol. In general, few adverse effects or drug interactions were noted in clinical trials of these herbal substances. Nevertheless, it is prudent for patients to notify their health care provider about any herbal products that they may be taking in order to reduce the likelihood of possible adverse drug interactions with any prescription medications that they may be taking simultaneously.

Another herbal substance that has been touted as an effective "natural" cholesterol-lowering agent is garlic. Is there any conclusive evidence that garlic can actually lower cholesterol levels? To investigate the effect of garlic on lowering cholesterol levels in people with high blood cholesterol, researchers conducted a meta-analysis of 13 randomized, double-blind, placebo-controlled clinical trials. The results of this study, published in the September 2000 in the Annals of Internal Medicine (Volume 133; No. 6, pp. 420-429) can be summarized as follows:

  • Although garlic was found to be more effective than a placebo for lowering the total levels of blood cholesterol, the magnitude of the decrease was only modest.

  • A few of the clinical trials reported that garlic slightly reduced the levels of LDL cholesterol and also slightly increased the levels of HLD cholesterol, however, these differences were not statistically significant when compared to placebo.

  • Garlic appears to be safe and was associated with few adverse effects. The most common problems reported were:

    • gastrointestinal disturbances
    • "garlic breath"
    • body odor

A more recent study published in 2007 conducted by researchers at Stanford University in California involving 192 people with modereately high levels of LDL ("bad") cholesterol reported that garlic was ineffective in lowering the levels of LDL cholesterol. According to the authors of this study, "the lack of effect (of garlic) was compelling and clear".