A food supplement having prophylactic and-cancer effects, wherein the supplement comprises 20 to 99.99% by weight of a product of biosynthesis by the productive microorganism Penicillium oxalicum var. Armeniaca CCM 8242, obtained by fermentation of a nutrient broth containing carbohydrates and ammonia nitrogen, and 0.01 to 8'% by weight of a physiologically inert carrier, and optionally auxiliary additives.