Diet and Prognosis in Women with Breast Cancer.

Women who have obesity or who have metabolic abnormalities, including diabetes, prediabetes, or hyperglycemia/insulinemia, have poorer survival compared with other women with breast cancer. Data are lacking on specific lifestyle modifications to prevent or treat these conditions to improve women's chances of survival from breast cancer. The Nurses' Health Study cohorts provide new evidence that diets with the potential to elevate circulating insulin or glucose are associated with breast cancer prognosis. The researchers found statistically significant evidence that women in the highest quintile of glycemic load had a 31% higher risk of breast cancer-specific mortality and a 26% higher risk of all-cause mortality. While a randomized controlled clinical trial testing if a reduced glycemic load diet reduces recurrence or death would be optimal, evidence from this observational study suggests that diet matters in survival from breast cancer. The dietary guidelines provided by the World Cancer Research Fund/American Institute for Cancer Research, the American Cancer Society, and the American Society for Clinical Oncology, which collectively emphasize increased intake of vegetables, fruits, whole grains, and legumes, and reduced intake of sugar, calorie-dense foods, and sugary drinks, are reasonable for most breast cancer survivors to follow for optimal health.