Drinking sugary drinks raises the risk of developing gout, a new local study shows.
Research from Otago University, which examined blood samples from about 1600 New Zealanders between 2007 and 2012, revealed sugar-sweetened drinks reversed the effectiveness of a human gene variant designed to protect against gout.
Associate Professor Tony Merriman, from the university's Biochemistry Department, said the gene variant took on "Jekyll and Hyde" characteristics when people consumed sugary drinks.
Downing a 300ml serving of sugar-sweetened drink increased the chance of gout by 13 per cent, he said.
A standard can of soft drink was about 355ml.
Having two servings in a day would double the risk, Professor Merriman said.
Study findings showed when the variant of the gene behaved correctly, it assisted in the transport of uric acid out of the blood stream and facilitated its excretion through the kidney.
Sugary drinks reversed this action, causing uric acid to be transported back into the blood-stream.
Because gout was caused by a build up of uric acid in the blood, those who consumed sugary-drinks were more likely to develop it.
Professor Merriman referred to the interaction as "unpredictable."
"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 secretion of uric acid from the kidney."
The study also showed consumption of sugar-sweetened soft drinks increased the risk of gout to all New Zealanders, including Maori and Pacific people, independent of their weight.
Previous US research has already proved people of European ancestry were more likely to develop gout from drinking high-fructose corn syrup soft drinks.
Study participants, who were mainly from Auckland and Christchurch, were also asked how much soft-drink and fruit juice they consumed.
Five per cent of participants of European heritage were drinking more than 1 litre of sugar-sweetened drink, compared to 14.4 per cent of Maori and 16.6 per cent of Pacific Island people.
Professor Merriman said gout attacks could be prevented by the prescribed daily use of the medicine allopurinol, which lowered the production of uric acid in the blood.
People suffering from gout should not drink any sugary drinks and take this medication, he advised.
The study was published in the international journal Annals of the Rheumatic Diseases today.