This systematic review and meta-analyses explored the strength of evidence on efficacy and safety of Ayurvedic herbs for hypercholesterolemia. Methods: Literature searches were conducted and all randomized controlled trials on individuals with hypercholesterolemia using Ayurvedic herbs (alone or in combination) with an exposure period of ≥ 3 weeks were included. The primary outcomes were total cholesterol levels, adverse events, and other cardiovascular events.
A total of 32 studies with 1386 participants were found. They tested three Ayurvedic herbs:
- Allium sativum (garlic),
- Commiphora mukul (Guggulu),
- Nigella sativa (black cumin).
The average duration of intervention was 12 weeks. The meta-analysis of the trials showed that
- Guggulu reduced total cholesterol and low-density lipoprotein levels by 16.78 mg/dL (95% C.I. 13.96 to 2.61; p-value = 0.02) and 18.78 mg/dL (95% C.I. 34.07 to 3.48; p = 0.02), respectively.
- Garlic reduced LDL-C by 10.37 mg/dL (95% C.I. -17.58 to -3.16; p-value = 0.005).
- Black cumin lowered total cholesterol by 9.28 mg/dL (95% C.I. -17.36, to -1.19, p-value = 0.02).
Reported adverse side effects were minimal.
The authors concluded that there is moderate to high level of evidence from randomized controlled trials that the Ayurvedic herbs guggulu, garlic, and black cumin are moderately effective for reducing hypercholesterolemia. In addition, minimal evidence was found for any side effects associated with these herbs, positioning them as safe adjuvants to conventional treatments.
For the following reasons, I fail to see how these conclusions can be justified:
- Too many of the included studies are of poor quality.
- Only for garlic are there a sufficient number of trials for attempting to reach a generalizable conclusion.
- Giving garlic to patients with hypercholesterolemia is hardy Ayurvedic medicine.
- Even the effect of the best-tested herbal remedy, garlic, is not as large as the effects of conventional lipid-lowering drugs.
- Conclusions about the safety of medicines purely on the basis of RCTs are unreliable.
- The affiliations of the authors include the College of Integrative Medicine, Maharishi International University, Fairfield, USA, the School of Science of Consciousness, Maharishi University of Information Technology, Noida, India, and the Maharishi International University, Fairfield.