Crayfish

Crayfish is notable for histamine. Clear on FODMAPs, lactose, gluten, fructose, oligosaccharides, sorbitol, sucrose, tyramine, salicylate, nickel and oxalates.

Crayfish contains moderate levels of histamine. Crayfish are liberators like all crustaceans, and their own histamine is governed by the cold chain rather than by the species: storage temperature, how they were handled and which bacteria came with them decide what has formed by the time they reach you. They are usually cooked whole and shelled at the table, which keeps the gut with the meat. The Swiss list rates it 2 of 3 under “crayfish” and marks it H! for rapid histamine formation and L for liberators of mast cell mediators. The letters are a presumed reason, not a measurement. That list is Visciano's, and the species is not on it. What the paper does not cover is liberation — it is about amines formed in the food, and the liberator classification above comes from SIGHI. Amounts vary by brand and recipe, so always check the label of the exact product.