Oyster sauce

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

Oyster sauce contains moderate levels of histamine. Oyster sauce is not fermented oyster, and it is fermentation that makes histamine: it is oyster extract cooked down with sugar, salt and usually caramel colour, and most brands contain very little oyster. That is why it sits below fish sauce despite the similar shelf position - the process is reduction rather than fermentation.

Oyster sauce contains moderate levels of tyramine. Oyster sauce is not fermented oyster: it is oyster extract cooked down with sugar, salt and caramel, and most brands contain very little oyster. Reduction is not fermentation, which is why its tyramine sits below the others' in this group despite sharing their shelf.

Oyster sauce contains moderate levels of nickel. Oyster sauce is reduced oyster extract, and oysters filter seawater for a living. The reduction concentrates what they filtered; the small pouring portion is what keeps this moderate. The second French Total Diet Study ranks the food groups for nickel rather than valuing them, and tofu heads that ranking.

Oyster sauce contains only low levels of FODMAPs. Oyster sauce rests on starch or a refined base, and starch is not a FODMAP - it is a polysaccharide, digested to glucose in the small intestine. What would change the answer is an added ingredient rather than the base: onion or garlic powder in the seasoning, or inulin added as fibre. Amounts vary by brand and recipe, so always check the label of the exact product.