The biochemist Bruce Ames and his colleagues have found that “99.99% (by weight) of the pesticides in the American diet are chemicals that plants produce to defend themselves. Only 52 natural pesticides have been tested in high-dose animal cancer tests, and about half (27) are rodent carcinogens; these 27 are shown to be present in many common foods.”
此外，包括有机和传统食品在内的人类饮食中“天然”出现绝大多数农产品上发现的杀虫物质。生物化学家布鲁斯·埃姆斯及其同事发现“美国人饮食中（以重量计）99.99%的农药是植物自身防御产生的化学物质。高剂量动物致癌试验只检出52种天然农药，其中约半数（27种）为啮齿类动物致癌物质；许多常见食物中都含有这27种物质。”