Many foods we trust are only safe because of traditions we barely notice anymore. Cassava must be soaked and cooked to remove cyanide; green-tinged potatoes should be thrown away, not trimmed and eaten. Starfruit seems exotic and harmless, yet for people with kidney disease, even a small glass of juice can trigger confusion, seizures, or death. Cherry pits, apple seeds, and bitter almonds all carry cyanide-producing compounds that become dangerous in large amounts, turning “natural” into lethal.