The
use of alternative medicines for the management of diabetes is
widespread in the Indian subcontinent, mostly in the form of so-called
nutraceuticals (eg, capsules made of fenugreek or bitter melon extract).
In 2014, the Indian Government created an independent Ministry of AYUSH
(Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homoeopathy),
emphasising the prominence of alternative medical practices in the
country. Furthermore, Ayurveda and other forms of alternative medicine
are increasingly visible in the public domain, with some officials
describing them as effective and emphasising a supposed absence of
side-effects.
We searched the scientific literature to
gauge whether firm claims of efficacy and safety regarding Ayurvedic
treatments could be made, as is increasingly being done in the
mainstream media in India. We identified three major systematic reviews
of studies investigating the use of Ayurvedic treatments for diabetes.
In 2001, Hardy and colleagues
1
discussed the major methodological limitations in the evidence base:
few randomised trials, underpowered studies, and the use of
inappropriate statistical methods. That human trials with Ayurvedic
medicines fall short of methodological standards was again emphasised in
a systematic review in 2004.
2 About 7 years later, Sridharan and colleagues
3
reviewed the existing literature and noted that, because of
methodological deficiencies and small sample sizes, no definite
conclusions regarding the efficacy of Ayurvedic treatments could be
drawn, affirming that there was insufficient evidence to recommend their
use in routine clinical practice.
There are other
important issues pertaining to alternative medicines in India. For
example, there is indistinct compartmentalisation between herbs,
Ayurvedic medicines, and functional foods. As such, there is the
possibility of interactions between the potential bioactive ingredients
of the herbs used in alternative medicines (which are often given as
mixed formulations), the toxicity of which should be properly studied in
keeping with national guidelines (
appendix).
Notably, Indian guidelines have waived or relaxed the rules for
rigorous pharmacological and toxicology studies for Ayurvedic products (
appendix), provided that medicines are “prepared in same way as mentioned in ancient Ayurvedic treatises” such as
Charaka Samhita or similar texts, purported to have been written and rewritten between the 6th century BCE and the 1st century CE.
The
safety of Ayurvedic preparations is also a major concern. In addition
to several reports of heavy metal toxicity due to these drugs, in one
study, a fifth of Ayurvedic medicines manufactured in the USA and India
contained detectable lead, mercury, or arsenic compounds, which exceeded
one or more standards for acceptable daily intake of toxic metals.
4
Among the metal-containing products, 95% were sold by US websites and
75% were claimed to have been manufactured in accordance with good
manufacturing practices.
If Ayurvedic medicines are to be
recommended for use in diabetes care, their active components should be
defined, their precise pharmacodynamic actions identified, and
bioassays for their standardisation developed; essentially, rigorous
methods of modern pharmaceutical drug testing should be applied.
Importantly, toxicity of these compounds remains an area of major
concern. Based on current scientific data, there is scant scientific
basis for the use of these products in the management of diabetes.
We declare no competing interests.
Article Info
Supplementary appendix