A recent systematic review and meta-analysis from The BMJ attempts to define a relationship between fructose intake and the development of gout and hyperuricemia. Researchers were only able to identify two prospective cohort studies which met their selection criteria; both of which pertained to fructose intake and gout but did not address incidence of hyperuricemia. One study was conducted in male health professionals aged 40 to 75 years and the second was conducted in female nurses aged 30 to 55 years. In both studies, dietary intakes were assessed via food frequency questionnaire and medical history and incidence of gout were self-reported. Adjustments to the statistical model were made for the following factors: BMI, age, total energy intake, alcohol consumption, diuretic use, history of hypertension, history of renal failure, menopause status, use of hormone therapy, caffeine intake, total vitamin C, and percentage of energy from total carbohydrates.
It was noted that the median fructose intake was ~7.2% of total energy intake in the lowest quantiles and ~11.9% in the highest quantiles. The main sources of dietary fructose were orange juice, sugar sweetened beverages, apples, raisins, and oranges. When using the most-adjusted model, researchers found “a significant overall association between fructose intake and increased risk of incident gout with a pooled RR of 1.62 (95% CI 1.28 to 2.03) with no evidence of significant interstudy heterogeneity…This model allows for the effects of fructose compared with isocaloric exchange for other carbohydrates to be estimated.” Researchers conclude “The results of our pooled analysis indicated that total fructose consumption was positively associated with an increased risk of developing gout by 62% when comparing extreme quantiles of fructose intake.”
Points of Consideration
Researchers highlight a number of limitations to their analysis. While the number of participants was high (n=125,999) the participants were recruited for two studies that were limited to health care workers in the USA. Moreover, one study reported that its male participants were predominantly Caucasian. Together, these factors contribute to low generalizability. Furthermore, because there were only two studies utilized in this analysis, researchers were unable to assess publication bias or perform sensitivity. Lastly, because both of the studies examined were observational, no cause and effect relationship can be determined.