Open Collections

Abstract

Background: Coffee, tea, and soft drinks are among the most widely consumed beverages worldwide, yet their associations with cancer remain unclear. This study aims to clarify associations between coffee, tea, and soft drink intake and cancer risk in a large prospective cohort. Objectives: To review existing studies on the links between coffee, tea, and soft drinks and cancer risk, summarizing findings and identifying research gaps. To evaluate the association between coffee, tea, and soft drink intake and cancer risk in the Alberta’s Tomorrow Project. Methods: First, a scoping review of the literature was conducted to summarize current research and identify existing research gaps. Subsequently, a population-based analysis was performed using Alberta’s Tomorrow Project cohort, with dietary intake data collected using the Canadian Diet History Questionnaire (CDHQ), linked to incident cancer data from the Alberta Cancer Registry. Descriptive statistics summarized baseline information, including socio-demographic, disease history and behavioral indicators. Case-specific Cox proportional hazards models were employed, adjusted for confounders and competing events—to investigate associations between beverage intake and cancer risk. Restricted cubic splines were used to test for potential nonlinear associations. Results: A total of 25,146 participants were included in the analysis. The median follow-up time was 15.6 years (range: 1.0–21.1 years), and 4,515 incident cancer cases were identified. After adjusting for energy intake, BMI, age, smoking, and other confounders, the Cox proportional hazards analysis revealed that the highest quartile of coffee consumption was significantly associated with increased risk of lung cancer, leukemia, and colorectal cancer, while there was a protective association with prostate cancer. In contrast, tea consumption—particularly more than 400 ml per day—was linked to reduced risk for prostate, lung, and breast cancers. The consumption of soft drinks was significantly associated with elevated hazard ratios for breast cancer, colorectal cancer, and melanoma. Conclusion: Our findings highlight that the highest quartiles of coffee and soft drinks was associated with increased risks for several cancers, including breast, colorectal, and lung cancer, whereas tea consumption showed an inverse association with cancers, including breast, prostate, and lung cancer. These associations warrant further investigation to elucidate the underlying biological mechanisms