Research from New Zealand suggests there is a biological basis for the long held belief that tomatoes trigger gout flares.

In a survey of 2051 New Zealanders with clinically diagnosed gout 71% reported having one or more food triggers. One-fifth of these respondents listed tomatoes as a trigger.

The researchers then analysed data from 12,720 male and females participating in NHANES and ARIC studies.

This data showed that tomato consumption was linked to higher levels of uric acid.

One serve per week of tomato increased serum urate by 0.7 μmolL ⁻¹ whereas alcohol increased serum urate by 2.3 μmolL ⁻¹ per serving per week and sugar-sweetened drinks increased urate 0.4 μmolL ⁻¹ per serve per week, reported the researchers in BMC Musculoskeletal Diseases.

Together meat and seafood increased urate 0.5 μmolL −1 and 2.4 μmolL −1 per extra serve per week, respectively.

“Tomatoes alter serum urate levels to an extent comparable to other established dietary risk factors for gout,” the study authors wrote.

While the research did not categorically prove that tomatoes trigger gout attacks, it does suggest that this food can alter uric acid levels to a degree comparable to other commonly accepted gout trigger foods.

“To our knowledge this is the first time tomatoes have been associated with serum urate, suggesting that the avoidance of tomatoes by people with gout may have a biological basis,” they concluded.