Association of Artificially Sweetened Beverage Consumption and Urinary Tract Cancers in the Women's Health Initiative Observational Study.

Background: Insufficient data exist to conclude whether consumption of artificially sweetened beverages is associated with a higher risk of urinary tract cancers. Objective: We sought to investigate whether urinary tract cancer incidence differed among women who consumed various amounts of artificially sweetened beverages. Design setting and participants: This was a secondary analysis of data from the Women's Health Initiative Observational Study, a multicenter longitudinal prospective study of the health of 93 676 postmenopausal women with a mean follow-up time of 13.5 yr. Women were identified at 40 clinical centers across the USA and enrolled from 1993 to 1998. Women between the ages of 50 and 79 yr were enrolled. We included women who answered questions about artificially sweetened beverage consumption and reported no prior urinary tract cancer diagnoses. The frequency of artificially sweetened beverage consumption was categorized as follows: rare artificially sweetened beverage consumption (never to fewer than one serving per week), frequent consumption (one to six servings per week), and daily consumption (more than one servings per day). Outcome measurements and statistical analysis: The incidence of urinary tract cancer reported during subsequent visits until February 28, 2020 was recorded. Demographic characteristics were compared between those with varying levels of artificially sweetened beverage consumption. Descriptive statistics were used to report the rates of urinary tract cancer diagnosis, and Cox regression models were constructed to determine hazard ratios and adjust for potential confounders. Results and limitations: We identified 80 388 participants who met the inclusion criteria. Most participants (64%) were infrequent consumers of artificially sweetened beverages, with 13% (n = 10 494) consuming more than one servings per day. The incidence of urinary tract cancers was low, with only 804 cases identified. Cox regression models showed that frequent artificially sweetened beverage consumption was associated with a higher risk of kidney cancer (adjusted hazard ratio 1.34, 95% confidence interval 1.03-1.75). There was no significant association between artificially sweetened beverage intake and bladder cancer. Conclusions: Frequent consumption of artificially sweetened beverages may be associated with a higher risk of kidney cancer among postmenopausal women. Patient summary: A secondary analysis of the Women's Health Initiative Observational Study showed that higher consumption of artificially sweetened beverages was associated with a higher risk of kidney cancer.