The study's lead author, Associate Prof Tony Merriman, said the findings showed for the first time that sugary drinks reversed the benefits of a gene variant which usually protected against gout.
Gout, which is caused by high levels of uric acid in the blood, is the most common form of arthritis in New Zealand, with particularly high rates in men.
When the variant of the gene SLC2A9 behaved correctly, it helped transport uric acid out of the bloodstream and facilitated its excretion through the kidney, Prof Merriman said.
''But when people with this gene variant consume sugary drinks, it takes on Jekyll-and-Hyde characteristics; the apparent function of the gene variant reverses, such that we think uric acid is instead transported back into the bloodstream and the risk of gout is increased.
''So, not only does sugar raise uric acid in the blood due to processing in the liver, but it also appears to directly interfere with excretion of uric acid,'' he said.
Previous studies had shown that in the general population each daily 300ml serving of sugar-sweetened drink increased the chance of gout by 13%.
Prof Merriman said the findings - especially because they were gathered from New Zealand participants - added more weight to calls to increase taxes on sugary drinks.
''They shouldn't be as cheap as they are.''
People should also be more aware of the amount of sugary drinks they were consuming''If you have either got gout or are at risk of gout, you should not be drinking sugary drinks. I would say aim for zero.''
Alternatives included drinking coffee, which had been shown to reduce the risks of gout, and sugar-free soft drinks.
The study, a collaboration between Otago and Auckland Universities was published in the international journal Annals of the Rheumatic Diseases yesterday.
Dr Merriman wished to thank the study's participants and Health Research Council and Arthritis New Zealand for providing funding.
