Meta-analysis concluded that in women with breast cancer a low-fat diet. reduces the risk of breast cancer recurrence by 23% and all-cause mortality by 17%. (Xing MY).
In the WHI diet modification study there was a reduced incidence of ER positive, PR negative breast cancers and a 20% reduction in deaths from breast cancer in the low fat dietary intervention group.
Adoption of a low-fat dietary patterns associated with increased vegetable, fruit, and grain intake significantly reduces the risk of death from breast cancer in postmenopausal women (WHI).
Consuming a diet with a high glycemic index or glycemic load may increase the risk of breast cancer (NutriNet-Santé study).
The mechanisms involved could be elevated postprandial glucose and insulin levels and insulin resistance, as well as diabetes and obesity.
The researchers evaluated 103,020 patients – 81,256 of them women – who had a mean age of 42 years and did not have cancer or diabetes at baseline.
The patients’ mean total carbohydrate intake was 198.4 g/day, their mean sugar intake was 92.8 g/day, their mean dietary glycemic index was 50.7, and their mean dietary glycemic load was 101.2 g/day.
The main contributors to dietary glycemic load were bread (27%), sugary items such as cakes and breakfast cereals (25%), and starch-based and processed savory dishes such as pizza (13%).
At a median follow-up of 7.7 years, 927 patients had received a breast cancer diagnosis and 3,131 had received any cancer diagnosis.
Higher dietary glycemic load was significantly associated with an increased risk of cancer overall and postmenopausal breast cancer.
The association with the carbohydrate intake measure was significant for both premenopausal and postmenopausal breast cancer.
Patients have reduced overall cancer risk if their diets had a higher contribution of low-glycemic-index foods to carbohydrate intake or caloric intake.
Potential mechanisms for the observed associations is weight gain, inflammation, oxidative stress, and increased insulin levels.
Certain popular diets with higher fiber content and more whole-grain foods, such as the Mediterranean diet, also have a lower glycemic index.
Dietary modification to lower glycemic load is a viable option for broad-scale prevention.
Observational data support associations between higher glycemic load diets and higher breast cancer risk.