Soy sauce

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

Yes — soy sauce is high in tyramine. Soy sauce is brewed for months with mould, yeast and lactic bacteria in turn, each stage breaking the soy protein down further - which is exactly what produces tyramine. It is poured in small volumes and it is very concentrated, so the volume is the only thing keeping the dose down.

Yes — soy sauce is high in gluten. Standard soy sauce is brewed with wheat and contains gluten. Choose tamari labelled gluten-free as a safe alternative.

Soy sauce contains moderate levels of histamine. Soy sauce is brewed for months with mould, yeast and lactic bacteria in turn, and each of those stages breaks protein down further - which is exactly what produces amines. It is used by the spoonful, which is the only thing keeping it where it is rather than higher. There is no low-histamine soy sauce. Gardner's narrowed MAOI diet names it, and names it as a category — "soy sauce and soy bean condiments" — which covers miso, tamari and the rest of the shelf rather than one bottle.

Soy sauce contains moderate levels of salicylate. The salicylate of a soy sauce comes from the long ferment rather than from any added spice, and no measurement separates soy sauce from tamari here - the two carry the same level for that reason. It is poured by the spoonful, so the portion stays modest unless the sauce is the dish rather than the seasoning. Amounts vary by brand and recipe, so always check the label of the exact product.