Ayurvedic medicines are frequently contaminated with lead, mercury and arsenic, a new study found. The toxic metals were found in the traditionally Indian herbal mixtures at dangerously high levels.

Although Ayrvedic medicine has become an increasingly accepted alternative medical treatment in America, the study conducted by researchers at the Boston University School of Medicine and Boston Medical Center notes that more than 80 people have developed lead poisoning worldwide from Ayurvedic medicines since 1978.

The study found that one in five of Ayurvedic medicines sold online in America contains toxic metals.

Researchers found that 20.7% of the herbal products purchased from sites selling these types of medicines contained lead, mercury and arsenic. 21.7 percent of the products manufactured in the United States contained toxic metals and 19% of the Indian-made products contained metals. Those products that were identified as containing metals contained unacceptable levels of lead, mercury, and/or arsenic. Several Indian-manufactured Ayurvedic medicines could result in lead and/or mercury ingestions 100 to 10,000 times greater than acceptable limits, according to the study.

Dr. Robert Saper, a Boston University professor of family medicine who led the study, said the findings should draw the attention of the Food and Drug Administration on the world of pills and herbs that are used as alternative treatments. Researchers are calling for tougher regulations for all those pills, herbs and powders that are classified as dietary supplements. “New FDA regulations and current Indian policies do not specify any maximum acceptable concentrations or daily dose limits for metals in dietary supplements for domestic use,” researchers said. “We suggest strictly enforced, government-mandated daily dose limits for toxic metals in all dietary supplements and requirements that all manufacturers demonstrate compliance through independent third-party testing.” The FDA doesn’t specify how much lead is permitted in these products, but it has the power to ban products if they’re found to be unsafe.

Arsenic can cause cancer, lead and mercury lead to damage in the kidneys and brain especially in the case of children. The symptoms of lead poisoning include fatigue, anemia and abdominal pain.

Although Ayurvedic medicines are largely manufactured for use in adults to treat problems such as indigestion to infertility, the researchers found that 4 % of the medicines they examined were labeled for use in children.

The traditional medicines come in two major types: herbal-only and rasa shastra, which is an ancient practice of deliberately combining herbs with metals (e.g., mercury, lead, iron, zinc), minerals (e.g., mica) and gems (e.g., pearl). According to rasa shastra experts, these medicines are safe and therapeutic when properly prepared and administrated. Rasa shastra medicines were more than twice as likely as non-rasa shastra products to contain detectable metals (40.5 percent vs 17.1 percent) and had higher concentrations of lead and mercury.

According to the original texts, the goal of Ayurveda is prevention as well as promotion of the body’s own capacity for maintenance and balance. Ayurvedic medicines have been used to treat acne, allergies, asthma, anxiety, arthritis, chronic fatigue syndrome, colds, colitis, constipation, depression, diabetes, flu, heart disease, hypertension, immune problems, inflammation, insomnia, nervous disorders, obesity and ulcers.

Saper and his colleagues recommended that the herbal Ayurvedic medicines should be used rather than the rasa shastra medicines. Saper told Reuters Health that products made by members of the American Herbal Product Assn, including capsules, liquids, pastes are less likely to contain toxic metals.