A new study has reported that high consumption of dietary fiber is associated with lower risk of death among breast cancer survivors, but the link to breast cancer-specific death is weak. The study was designed to investigate the associations between fiber, carbohydrates, glycemic index/load and breast cancer prognosis. The glycemic index ranks foods based on their immediate effect on blood glucose levels. Glycemic load is calculated by multiplying the glycemic index, carbohydrate content, and intake frequency of individual foods. It is possible that consumption of fiber, carbohydrates, and high glycemic index or high glycemic load foods influences breast cancer survival, but consistent and convincing evidence is lacking.

The study included 688 breast cancer survivors with stage 0 to IIIA breast cancer in the Health, Eating, Activity, and Lifestyle (HEAL) cohort. Study participants included both premenopausal and postmenopausal women from Western Washington State, Los Angeles County, and New Mexico. The women were followed for a median of 6.7 years after diagnosis. A food frequency questionnaire was used to assess usual diet. Surveillance, Epidemiology, and End Results (SEER) registries and medical records were used to collect data concerning total mortality, breast cancer-specific mortality, non-fatal breast cancer recurrence and second occurrence data.

There were a total of 106 deaths, 83 breast cancer-specific deaths and 82 non-fatal breast cancer recurrences during the study period. High fiber consumption was found to be associated with lower overall likelihood of death. The benefit increased up to 9 grams of fiber per day, indicating a threshold effect. Fiber intake was found to be inversely associated with both breast-cancer specific death and risk of non-fatal recurrence or second breast cancer occurrence, but the results were far from statistically significant. Further studies to evaluate and confirm this relationship are needed in order to offer effective dietary strategies for breast cancer patients, according to the authors.