Can Indian Systems of Medicine, such as Ayurveda, Siddha, and tribal medicines, be evidence-based? These questions have come to the fore in the Ramdev Baba Coronil dispute, in which an herbal product was claimed to be a cure for COVID-19 without sufficient scientific evidence.
Many decades ago, in Vietnam, during the war, more soldiers fighting the American army were dying from chloroquine-resistant malaria than American bullets. At the request of Ho Chi Min, China’s Mao Zedong initiated Project 523, sending researchers to scour traditional Chinese medicinal literature to identify herbs for malaria-like symptoms.
The most remarkable outcome was the discovery of artemisinin, a life-saving anti-malarial drug. Tu Youyou and her team, inspired by a 1,700-year-old treatise, discovered artemisinin using modern scientific methods. This breakthrough saved millions of lives and earned her a Nobel Prize in 2015.
Despite initial scepticism, clinical trials and pathophysiological studies confirmed the efficacy of artemisinin in controlling malaria. This robust evidence convinced the global health community and led the World Health Organization to endorse artemisinin. Today, academia worldwide investigates traditional Chinese medicine using modern science tools.
In the past, Indian systems were evidence-based
In ancient Indian philosophy and scientific texts, rationalistic epistemological keywords such as pariksha, anumana, ganita, yukti, nyaya, siddhanta, tarka, and anvesana share space with some form of mythology. According to Narasimha (dated 7th-8th century), the commentator of the Rasavaiseshika-sutra, attributed to Bhadanta Nagarjuna in the 5th-6th century, only two types of evidence count in Ayurveda: pratyaksha (directly observed) and anumana (conjectured/inferred), with no role for ‘belief’ in the sense of blind faith. (Na hy āyurvede pratyakṣārthānumeyārthābhyām āgamābhyām anyacchraddheyārthatvam asti, dṛṣṭaphalatvād iti. -RVSBh 3.45).
Caraka distinguished between Yuktivyapashraya bheshaja (reason-based) and Daivavyapashraya bheshaja (faith-based) therapies, emphasising the process of investigation, ‘pariksha‘, as critical for arriving at scientific truth. He stated that a claim becomes generally acceptable only after it has been thoroughly investigated by several investigators and is supported by robust and rational evidence.
Then why has Ayurveda fallen on the way?
From the sixth to tenth century CE, Ayurveda was a thriving and active field. New medicinal formulas were discovered and added to its extensive corpus. For example, Vagbhata (6th century CE) emphasised the importance of updating medical literature, ‘yuga anurupa,’ and authored new commentaries on Charaka Samhita and Sushruta Samhita. Dalhana (11th century CE) did not deter to amend and add two new iron formulations for anaemia treatment in his commentary on Sushruta Samhita.
“Ayurveda does not derive its authority because it is divined by Brahma; its merit comes simply from the verifiable truths it contains”, according to Vagbhata. However, numerous practitioners of Ayurveda believed that it was attained by ancient ‘rishis’ through their divine ‘yogic’ powers rather than as an experimental and experience-based scientific therapeutic system subject to critique.
“Subservience to the written word and textual authority, reinforced by the societal effects of caste hierarchy and mystical philosophies, gradually replaced the spirit of scientific adventurism and enquiry that characterised the work of Ayurvedic pioneers,” says MS Valiathan, a noted cardiologist and author of the book series Legacy of Charaka, Sushruta, and Vagbata.
In recent history, conservatism and mysticism were reinforced and promoted by the trope formulated by Captain G Srinivasa Murti, a practising medical doctor, to the committee constituted by the Government of the Madras presidency in 1921 under the chairmanship of Muhammad Usman on the question of recognising and encouraging indigenous medical systems. While modern Western science used external aids such as the microscope, telescope, spectroscope, and so on to comprehend things beyond the range of the senses, he asserted that the Hindu sages “sought to effect the same results, not by providing their senses with external aids, but by improving their own internal organs of sense”.
“The general unwillingness of contemporary practitioners of Ayurveda to question the wisdom enunciated in the classical Samhitas is contrary to the teachings of the sages in ancient India who preferred pratyaksha (direct evidence), anumana (inferential evidence), and yukti (logic) over shabda pramana (textual narrations)“ says Subhash C Lakhotia, professor of cytogenetics at the Banaras Hindu University and a pioneer in using the drosophila model to study Ayurvedic biology.
Western and Eastern
Not all invoke the divine to refuse scientific scrutiny; some hide behind cultural relativism. They argue that ‘allopathy’ is based on Western science and that Ayurveda is an epistemologically different yet valid knowledge system, which can be validated only using Ayurvedic logic and methods.
According to Ayurvedic physiology and anatomy, shukra (semen) is formed in majja (bone marrow), and urine is formed without the involvement of the kidneys. The text further states that the combination of semen and menstrual blood results in the creation of an embryo. All of these contradict ‘pratyaksha‘, and can these be accepted as alterative ‘ways of seeing’?
Kishor Patwardhan, a Kriya Sharir Ayurveda professor at Banaras Hindu University, explains that Ayurveda’s epistemology aligns with Nyaya Vaisheshika schools of thought, similar to modern science but using simple tools. “In ancient times, pratyaksha meant employing the sense organs to acquire knowledge; today, we use tools like microscopes for the same purpose”, he says.
Clinical trials
Randomised control trials (RCTs) are the gold standard for clinical trials assessing medication efficacy. Allopathy prescribes the same therapy for two people with identical diagnostic assessments.
However, Ayurvedic treatment is individualised based on the constitution (prakriti, agni, samhanana, etc). Due to its complexities, including multiple medications, mid-course correction, therapies, diet restrictions, and lifestyle modifications, the RCT appears to be not feasible for Ayurvedic clinical trials. Some argue that only case studies from the personal experience of Ayurvedic medical professionals are viable.
The situation is not hopeless, however. Recently, methotrexate-based treatment was compared to Ayurvedic intervention in patients with radiological indications of rheumatoid arthritis, proving the viability of double-blind, placebo-controlled trials even for individualised treatments. If there is a will, there is a way.
The elephant in the room
It is frequently argued that modern science gives stepmotherly treatment to studying old medical systems. But this is not the case. Prompted by a fortuitous talk by former President of the Indian National Science Academy, M S Valiathan, on Ayurveda and modern medicine, Naveen Khanna and his team at the International Centre for Genetic Engineering and Biotechnology (ICGEB) discovered a potent antiviral against all four dengue strains, after reviewing Ayurvedic literature. After years of research, they found that a botanical extract of Cissampelos pareira Linn (Cipa) was beneficial against dengue in both in vitro and animal models. Human clinical trials are currently underway.
Similarly, researchers at the CSIR-Indian Institute of Integrative Medicine in Jammu isolated Sinococuline, a bioactive constituent of Cocculus hirsutus, which has a powerful anti-dengue action, and discovered IIIM-290, a botanical medicine with anti-cancer characteristics.
China is investing massive amounts of government funds to revalidate ancient medicine using current evidence standards, by accepting therapies that work while rejecting those that do not. In India, we lack both funding and an unflinching commitment to evidence.
Aura of mystical, the critical hurdle
Sushruta maintains that medical interventions are trustworthy not just because they are effective in his own experience (pratyaksha / phaladarshana) but only because they have been rationally vetted by the community of specialists. He is seeking what is now known as a rigorous peer assessment before the claims are accepted. It is obvious that case studies cannot replace well-designed clinical trials in evaluating efficacy and assessing the underlying pathophysiology of disorders.
Naturally, classical medical texts from centuries ago contain imprecise anatomy and physiology, with outdated theories of pathophysiology and aetiology. Yet, practitioners often claim divine revelation and do nothing to update or change this knowledge. Unearthing the biological basis of this knowledge trove can benefit both the Indian System of Medicine and biology.
(The author acknowledges Krishna GL, particularly in his paper ‘Ayurveda awaits a new dawn’, for providing perspectives on the philosophical and epistemological aspects of Ayurveda)
