Ayurveda

Ayurveda (; IAST: āyurveda) is an alternative medicine system with historical roots in the Indian subcontinent. It is heavily practised throughout India and Nepal, where as much as 80% of the population report using ayurveda. The theory and practice of ayurveda is pseudoscientific and toxic metals including lead and mercury are used as ingredients in many ayurvedic medicines. Ayurveda therapies have varied and evolved over more than two millennia. Therapies include herbal medicines, special diets, meditation, yoga, massage, laxatives, enemas, and medical oils. Ayurvedic preparations are typically based on complex herbal compounds, minerals, and metal substances (perhaps under the influence of early Indian alchemy or rasashastra). Ancient ayurveda texts also taught surgical techniques, including rhinoplasty, lithotomy, sutures, cataract surgery, and the extraction of foreign objects. Historical evidence for ayurvedic texts, terminology and concepts appears from the middle of the first millennium BCE onwards. The main classical ayurveda texts begin with accounts of the transmission of medical knowledge from the gods to sages, and then to human physicians. Printed editions of the Sushruta Samhita (Sushruta's Compendium), frame the work as the teachings of Dhanvantari, the Hindu deity of ayurveda, incarnated as King Divodāsa of Varanasi, to a group of physicians, including Sushruta. The oldest manuscripts of the work, however, omit this frame, ascribing the work directly to King Divodāsa. In ayurveda texts, dosha balance is emphasised, and suppressing natural urges is considered unhealthy and claimed to lead to illness. Ayurveda treatises describe three elemental doshas: vāta, pitta and kapha, and state that balance (Skt. sāmyatva) of the doshas results in health, while imbalance (viṣamatva) results in disease. Ayurveda treatises divide medicine into eight canonical components. Ayurveda practitioners had developed various medicinal preparations and surgical procedures from at least the beginning of the common era. Ayurveda has been adapted for Western consumption, notably by Baba Hari Dass in the 1970s and Maharishi ayurveda in the 1980s. Although some Ayurvedic treatments can help relieve some symptoms of cancer, there is no good evidence that the disease can be treated or cured through ayurveda. Several ayurvedic preparations have been found to contain lead, mercury, and arsenic, substances known to be harmful to humans. A 2008 study found the three substances in close to 21% of US and Indian-manufactured patent ayurvedic medicines sold through the Internet. The public health implications of such metallic contaminants in India are unknown.