Sugar-Sweetened Beverages, Artificially Sweetened Beverages, and Breast Cancer Risk: Results From Two Prospective US Cohorts

OBJECTIVES: Whether consumption of sugar-sweetened beverages (SSBs) or artificially sweetened beverages (ASBs) is associated with risk of breast cancer is of public health interest. Therefore, we aimed to evaluate associations between consumption of SSBs and ASBs with risk of total and subtype-specific breast cancer. METHODS: We followed 80,677 women from the Nurses’ Health Study (NHS; 1980 to 2016) and 86,115 women from the Nurses’ Health Study II (NHSII; 1991 to 2017) who were free from breast cancer at baseline. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: We documented 10,248 breast cancer cases during 3,990,008 person-years of follow-up. Consumption of SSBs or ASBs were not associated with total breast cancer risk; pooled HR (95% CI) comparing extreme categories were 1.05 (0.97, 1.15) and 0.97 (0.91, 1.03), respectively. In cohort-specific analysis, SSBs were associated with a higher risk of breast cancer in NHS (HR (≥1/day vs. < 1/month) 1.12; 95% CI 1.00, 1.24; P-trend = 0.03). We observed a significant interaction by BMI (P-interaction = 0.02), where a modestly higher risk of breast cancer with each serving per day increment of SSBs was found in lean women (BMI < 25 kg/m(2)) (HR, 1.06, 95% CI, 1.01, 1.12), but not among overweight or obese women (BMI ≥ 25 kg/m(2)) (HR, 0.98, 95% CI, 0.93, 1.04). Moreover, in the pooled, fully adjusted analysis, compared to infrequent consumers (<1/month), those who consumed ≥ 1 serving of ASBs per day had a lower risk of luminal A breast tumors (HR, 0.88; 95% CI, 0.78, 0.99; P-trend = 0.01). CONCLUSIONS: Although no significant associations were observed overall, consumption of SSBs was associated with a modest higher risk of breast cancer among lean women. This finding could have occurred by chance and needs confirmation. Our findings also suggest no substantial increase in risk of breast cancer with consumption of ASBs. FUNDING SOURCES: This study was supported by grants from the National Institutes of Health, and the Breast Cancer Research Foundation. ARN was supported by a fellowship from the Spanish Association Against Cancer Scientific Foundation (FC AECC). The funding sources did not participate in the design or conduct of the study; collection, management, analysis or interpretation of the data; or preparation, review, or approval of the manuscript.