Background
We previously reported a positive association between sugar-sweetened beverage (SSB) consumption and obesity-related cancers; this association was not fully attributable to obesity and we hypothesised that there could be an underlying mechanism related to sugar that might be relevant to other cancers.
Aim
To investigate prospectively the association between SSB consumption and cancers not related to obesity, using data from the Melbourne Collaborative Cohort Study (MCCS). The association for artificially-sweetened beverages (ASB) was included for comparison.
Methods
Using the MCCS, which recruited men and women aged 40 to 69 years, we investigated associations between soft drink consumption (separately for SSB and ASB) at study entry and risk of all cancers other than the 13 identified by IARC as related to obesity. Hazard ratios (HR) and 95% confidence intervals were estimated using Cox regression.
Results
During 19 years follow-up of 35,202 participants, we ascertained 4,936 cancers unrelated to obesity (and 3,219 obesity-related). There was no association between consumption of SSB and non-obesity-related cancers. However, for those who consumed at least one ASB per day there was an increased risk of non-obesity related cancer, which was slightly stronger for younger participants (for >1 ASB/day: HR=1.29 (1.05, 1.59) for 63 years old vs HR=1.17 (0.91, 1.50) for 76 years old). There was a positive association between obesity-related cancers and frequency of SSB, but not ASB consumption.
Conclusion
Overall, there was no association between SSB consumption and risk of non-obesity-related cancers. There was a positive association between ASBs and non-obesity-related cancers, that was stronger for younger participants.