The U.S. Government Accountability Office, a government watchdog agency, released a report Wednesday on its investigation of deceptive or questionable marketing and sales practices for dietary supplements popular among seniors, including ginkgo biloba, garlic, ginseng, and chamomile. Those herbals and botanicals are loosely regulated under the 1994 Dietary Supplement Health and Education Act, which expressly prohibits claims that they diagnose, treat, cure, or prevent any disease. In addition they must carry a label disclaimer that statements have not been evaluated by the FDA.

The most egregious practices included suspect marketing claims that a dietary supplement prevented or cured cancer, heart problems and other extremely serious diseases, according to the report. Other dietary supplements were claimed to mitigate age-related medical conditions, such as Alzheimer’s disease and diverticular disorder. The GAO also found some claims that could be considered deceptive or questionable and provide consumers with inaccurate information. While conducting in-person and telephone conversations with dietary supplements sellers, GAO investigators, posing as consumers, were given potentially harmful medical advice by sales staff, including that they could take supplements in lieu of prescription medication. In making these claims, sellers put the health of consumers at risk, the GAO concluded.

That’s not all. The GAO found trace amounts of at least one potentially hazardous contaminant in 37 of the 40 herbal dietary supplement products it tested, though none of the contaminants were found in amounts considered to pose an acute toxicity hazard to humans.