Can Tomatoes Trigger Gout?

Some patients have shared that eating tomatoes caused them to experience gout flares, but these anecdotal claims have not been substantiated by medical literature.

But now, a new study provides evidence of this association.

Study author Tony Merriman, an associate professor at the University of Otago, told Pharmacy Times that pharmacists can be a helpful resource for patient education on this topic.

“In terms of advice pharmacists could give patients, it would be that if a patient knows tomatoes trigger their gout, then they should avoid tomatoes. Far more important than dietary advice, however, is advice and assistance for patients to get on urate-lowering therapy, if they are not already on it,” Merriman said. “The typical drugs available have a far greater reducing effect on urate levels than tomatoes have on increasing urate levels.”

Merriman and his fellow researchers examined 2051 patients with gout and asked them questions about gout flare trigger foods. The study subjects were asked whether certain foods triggered their gout, whether alcohol or seafood in particular triggered their gout, and, in an open-ended question, which food caused flare-ups.

A little more than 70% of the patients reported that they had at least 1 gout trigger food, and 20% of these patients mentioned tomatoes. In fact, tomatoes ranked as the fourth most commonly reported trigger food for gout flares.

The researchers also found an association between tomato intake and serum urate levels in both men and women.

High serum urate levels have been known as a major risk factor for gout, the researchers noted. When there is a “supersaturation,” monosodium urate crystals may deposit in joints and create an immune reaction.

“Avoiding tomatoes may be helpful for people who have experienced a gout attack after eating them, but with proper treatment, this doesn't have to be a long-term avoidance,” study author and PhD student Tanya Flynn said in a press release.

European patients from 3 other studies—the Atherosclerosis Risk in Communities Study, the Cardiovascular Health Study, and the Framingham Heart Study—were also examined to test for an association between serum urate and tomato intake. Their results also showed an association between serum urate and tomatoes.

In total, the study authors had examined 12,720 men and women from 3 US health studies.

“Whilst our data cannot support the claim that tomato consumption is a trigger of gout attacks, we provide support for the hypothesis that tomato consumption may trigger gout attacks through increasing serum urate,” the researchers concluded.

Thus, the researchers called for more research on the causal influence of tomatoes on serum urate levels.

“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,” the researchers stated.

There were 8.3 million US adults with gout in 2007-2008, according to the US Centers for Disease Control and Prevention (CDC).

The CDC also noted that gout incidence is on the rise, as the prevalence of gout increased by 1.2 percentage points over the past 2 decades.