Tonic water

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

Yes — Tonic water is high in salicylate. Tonic water is high in salicylates through its botanical flavourings, quinine and citrus among them. As a mixer it is easy to drink in volume without registering it. Neither study publishes a value for this particular drink.

Tonic water contains only low levels of histamine. Tonic water contains no histamine and does not liberate any. It is on the scale because it is a mixer - what it is mixed with is where the question usually lies.

Tonic water contains only low levels of nickel. Tonic water is carbonated water, sugar and a trace of quinine. None of the three carries nickel; what is measurable comes from the water supply, which varies by region more than by brand. The nickel here follows a national survey covering four decades - the kind of series that shows whether a level is drifting, which a single study never can.

Tonic water contains only low levels of oxalates. Tonic water contains no oxalate. On this axis it counts as fluid, and fluid is the first thing stone guidance asks for - volume dilutes urine and dilute urine crystallises less. Amounts vary by brand and recipe, so always check the label of the exact product.