While browsing through Biogerontology looking for the citation details of one of my publications (which appears to still be available only online), I came across this review, which kind of stands out because of its subject matter. And any paper with two citations from 300AD and 1300AD has to be looked at!
At the outset, I should say that I know next to nothing about Ayurveda, and that I am unwilling to take claims of efficacy of Complementary and Alternative Medicine (CAM) that lack a serious evidence-base seriously. (I regard Ayurveda as a CAM, as it most certainly is that from a western perspective). This paper is a brief review article that I suppose has been peer-reviewed, and seeks to review the impact of the therapy on brain ageing. Does it convince me?
My first observation is the lack of cited evidence. The review begins with a brief introduction to the Ayurvedic concept of ageing (in which the two early citations occur). This is followed by sections entitled “Rasayana therapy”, “Brain aging”, and “Neuronutrient Medhya Rasayanas” in which there are a few citations to demographic data but little to any evidence. There is a self-citation to a supplement to Ann. Neurosci. in the context of “scriptural” and “experience”-based evidence for efficacy, and a vague reference to recent scientific studies substantiating the ancient claims of efficacy, though unfortunately I can’t find this via PubMed. The bulk of the citations describing efficacy are self-citations in quite onscure journals.
The review finishes up with this:
The evidence-base for the efficacy of these medications is three-fold viz., (1) Literary and conceptual evidence, (2) Experience-based evidence and long tradition of use and (3) New scientific evidence which is being attempted now to be generated with the help of selected clinical and experimental studies which are obviously not adequate at present but it is worthwhile to project such evidences to provide lead for further studies.
Now this strikes me as a little odd for publication in a scientific journal. Of the three forms of evidence, (1) is not evidence at all; (2) is not evidence, but hearsay and habit; the authors say that (3), the actual evidence is “being attempted now to be generated”. I’m not convinced of a “magic pill” to delay brain ageing, and I’m also unconvinced of the efficacy herbal remedies where the evidence is just that they’ve been used for centuries. That bio-active compounds can be identified in plants is unquestionable however.
Ram Harsh Singh, K. Narsimhamurthy, Girish Singh (2008). Neuronutrient impact of Ayurvedic Rasayana therapy in brain aging Biogerontology, 9 (6), 369-374 DOI: 10.1007/s10522-008-9185-z