Consumption of sugar-sweetened and artificially sweetened soft drinks and risk of cancers not related to obesity

Consumption of sugary drinks increases the risk of obesity. Previously, we reported a positive association between sugar-sweetened soft drink consumption and obesity-related cancer, but this association was not fully explained by obesity; in contrast, we found no association for consumption of artificially sweetened soft drinks. Our aim was to determine whether the consumption of sugar-sweetened or artificially sweetened soft drinks was associated with cancers other than those currently identified as being related to obesity. We used data from the Melbourne Collaborative Cohort Study. Participants completed a 121-item food-frequency questionnaire at baseline including separate questions about the number of times in the past year they had consumed sugar-sweetened and artificially sweetened soft drinks. Cox regression models were fitted to estimate hazard ratios and 95% confidence intervals for the risk of cancers not related to obesity. During 19 years of follow-up, there were 35,109 eligible participants who developed 4,789 cancers not related to obesity. There was no association between frequency of consuming sugar-sweetened soft drinks and the risk of these cancers, but an unexpected positive association was observed for consumption of artificially sweetened soft drinks. Although, we did not find an association with sugar-sweetened soft drinks, we previously reported a positive association with obesity-related cancers, not fully explained by obesity. These findings leave unresolved the question of whether consumption of sugar-sweetened soft drinks influences cancer risk independently of their influence on body size.