Consumption of Sugars, Sugary Foods, and Sugary Beverages in Relation to Cancer Risk: A Systematic Review of Longitudinal Studies

Abstract

High sugar intake may increase cancer risk by promoting insulin–glucose dysregulation, oxidative stress, inflammation, and body adiposity, but epidemiologic evidence is unclear. Associations between dietary sugars and lifestyle-related cancer risk from longitudinal studies were evaluated. We systematically searched PubMed, Embase, and CINAHL and identified 37 prospective cohort studies (1990–2017) reporting multivariable adjusted risk estimates for dietary sugars in relation to cancer. Of 15 and 14 studies on total sugar and sucrose respectively, 11 reported a null association in relation to cancer. Of 14 studies on fructose, 8 reported null associations, and 2 reported protective and 4 reported detrimental associations. In two of five studies on added sugars, a 60–95% increased cancer risk was observed with higher intakes. In 8 of 15 studies on sugary foods and beverages, a 23–200% higher cancer risk was observed with higher sugary beverage consumption. In conclusion, most studies were indicative of a null association, but suggestive detrimental associations were reported for added sugars and sugary beverages.