Genes cause gout not diet

By Dr. Ananya Mandal, MDOct 11 2018

It has been believed for centuries that a diet rich in red meat and wine is associated with gout. This painful joint disease leads to extremely painful swelling of the joints (mainly of the great toes). This is caused due to elevation of uric acid in blood that gets deposited around the joints causing pain and inflammation.

Scientists have now shown that genetics could be the culprit behind causation of gout and diet has little do with gout exacerbation. The study titled, “Evaluation of the diet wide contribution to serum urate levels: meta-analysis of population based cohorts,” appeared in the latest issue of the British Medical Journal.

Gout in feet 3d illustration. Image Credit: Sciencepics / Shutterstock

The team of researchers from University of Otago, New Zealand, have found that poor and unhealthy dietary habits have been long blamed for this disease. Tudor King Henry VIII was one of its illustrious sufferers and thus the disease has also been called “disease of the kings”.

For this study the team looked at data of 16,760 Americans of European ancestry (8,414 males and 8,346 females) from five cohort studies. The participants were all adults and none of them were diagnosed with high uric acid levels or were taking medications for uric acid. Information regarding their gender, age, diet, uric acid, body mass index, socioeconomic and education levels, smoking status, alcohol consumption, menopausal status etc. were gathered. In addition they were genotyped.

Earlier evidence has shown that certain foods such as alcohol, beer, wine, soft drinks, red meat (pork, lamb and beef) and potatoes can raise the uric acid in blood and thus worsen gout whereas some foods such as eggs, peanuts, cheese, brown bread, cold cereal, non-citrus fruits, margarine, skimmed milk etc. can lower uric acid and thus benefit gout. This new study shows that the effect of these foods in increasing or decreasing the symptoms of gout or uric acid is less than one percent. The team of researchers compared healthy and gout-exacerbating diet and found that there was a variation of only 0.3 percent in the uric acid levels. Genetic predisposition on the other hand can explain around a quarter of all the cases of gout, the team wrote.

Post-Doctoral Fellow Dr. Tanya Major who led the study said diet changes can change urate levels to a small extent only. She said that genetics playing a major role was no surprise but what was surprising was the almost 100 fold difference in causation between genetics and diet. Genetics was found to be responsible for 23.9 percent cases she explained. She said that the researchers hoped physicians treating gout patients would keep this in mind while trying to manage urate levels.

Authors concluded, “diet explains very little variation in serum urate levels in the general population.” They agreed that this study results cannot be considered for people of non-European descent and those who already have gout since these populations have not been studied here. They write that this study adds to the common knowledge that “individual food items and estimates of dietary patterns explain very little variation in serum urate levels and genetic variants explain substantially more of the variation in serum urate levels compared with dietary patterns.”