NCI Seeks Toxicity Studies of Five Natural Substances

 RESEARCH TRIANGLE PARK, NC—The National Toxicology Program is considering an NCI request that it do toxicity studies of four herbal products and a substance found in vegetables: aloe vera, used in cosmetics and as a dietary supplement; ginseng, promoted to increase vigor; kava kava, sold as a mood elevator; milk thistle, believed by some to prevent cancer and protect the liver; and indole-3-carbinol, which occurs in cruciferous vegetables, and, according to some evidence, may reduce cancer risk.