Persin

One study found that persin has anti-cancer properties specifically related to breast tissue. The study suggesting persin causes DNA damage was conducted in vitro, bypassing the body's normal protective systems and making its findings largely irrelevant to real-world consumption. Persin is a naturally occurring fungicide produced by the avocado plant. Persin is toxic to animals but is not considered toxic to humans under normal consumption conditions. Some individuals may have sensitivities or allergic reactions to persin, and very large quantities could pose a theoretical risk. Persin is mostly concentrated in the avocado seed, bark, and leaves rather than the flesh.