British Medical Journal — Consumption of sweetened soft drinks and fructose is strongly associated with an increased risk of gout in men, finds a study published on bmj.com today.

Gout is a joint disease which causes extreme pain and swelling. It is most common in men aged 40 and older. It is caused by excess uric acid in the blood (hyperuricemia) which leads to uric acid crystals collecting around the joints.

In the United States, levels of gout have doubled over the last few decades, which coincided with a substantial increase in the consumption of soft drinks and fructose (a simple sugar and the only carbohydrate known to increase uric acid levels). The authors point out that sugary soft drinks are the largest single food source of calories in the US diet, and that the per capita intake of commercial high fructose corn syrup in the United States is now up to a whopping 29 kilograms (over 60 pounds) per year!

It is also known exactly how fructose spikes uric acid levels acutely. Fructose, like alcohol, increases blood levels of uric acid within minutes by using the high energy phosphate ATP in the liver for its own metabolism. This process converts ATP to AMP, which is a chemical forerunner to uric acid.

Conventional dietary recommendations for gout have focused on the restriction of purines (found in high levels in meat and meat products, especially liver and kidney) and alcohol but with no restriction of sugar sweetened soft drinks.

So researchers in the US and Canada examined the relation between intake of sugar sweetened soft drinks and fructose and the risk of gout.

They followed over 46,000 men aged 40 years and over with no history of gout. The men completed regular questionnaires on their intake of more than 130 foods and beverages, including sugar sweetened soft drinks and diet soft drinks, over a period of 12 years. Different types of fruits and fruit juices (high in natural fructose) were also assessed.

At the start of the study, and every two years thereafter, information on weight, regular use of medications and medical conditions were also recorded. Gout was diagnosed according to American College of Rheumatology criteria.

During 12 years of follow-up, the researchers documented 755 newly diagnosed cases of gout.

The risk of gout increased with increasing intake of sugar sweetened soft drinks. The risk was significantly increased with an intake level of 5-6 servings per week and the risk was 85% higher among men who consumed two or more servings of sugar-sweetened soft drinks per day compared to those who consumed less than one serving per month.

These associations were independent of other risk factors for gout such as body mass index, age, diuretic use, high blood pressure, alcohol intake, and dietary factors.

Diet soft drinks were not associated with the risk of gout.

Fruit juice and fructose-rich fruits (apples and oranges) were also associated with a higher risk of gout. However, the authors stress that this finding needs to be balanced against the benefit of fruit and vegetable intake to prevent other chronic disorders like high blood pressure, coronary heart disease, stroke and certain types of cancer.

In conclusion, the findings provide prospective evidence that consumption of fructose sweetened soft drinks and fructose is strongly associated with an increased risk of gout, say the authors. Furthermore, fructose rich fruits and fruit juices may also increase the risk. In contrast, diet soft drinks were not associated with the risk of gout.

A free PDF download of the original article is available here:

Soft drink, fructose intake, and gout risk