Associations of low-carbohydrate diets with breast cancer survival

Abstract

Background: The objective of this study was to evaluate the role of low-carbohydrate diets after breast cancer diagnosis in relation to breast cancer–specific and all-cause mortality. Methods: For 9621 women with stage I–III breast cancer from two ongoing cohort studies, the Nurses’ Health Study and Nurses’ Health Study II, overall low-carbohydrate, animal-rich low-carbohydrate, and plant-rich low-carbohydrate diet scores were calculated by using food frequency questionnaires collected after breast cancer diagnosis. Results: Participants were followed up for a median 12.4 years after breast cancer diagnosis. We documented 1269 deaths due to breast cancer and 3850 all-cause deaths. With the use of Cox proportional hazards regression and after controlling for potential confounding variables, we observed a significantly lower risk of overall mortality among women with breast cancer who had greater adherence to overall low-carbohydrate diets (hazard ratio for quintile 5 vs. quintile 1 [HRQ5vsQ1], 0.82; 95% CI, 0.74–0.91; ptrend =.0001) and plant-rich low-carbohydrate diets (HRQ5vsQ1, 0.73; 95% CI, 0.66–0.82; ptrend