Low-Fat Diets With Increased Vegetable, Fruit, and Grain Intake Linked to Reduced Risk of Breast Cancer Mortality in Postmenopausal Women – 20-year results.
In the trial, 48,835 postmenopausal women aged 50 to 79 years with no history of breast cancer and a dietary fat intake of ≥ 32% of energy were randomly assigned to receive either a usual diet (60%) or a dietary intervention (40%). The goal in the intervention group was to reduce fat intake to ≤ 20% of energy and increase intake of vegetables, fruits, and grains.
Key Findings
As previously reported, during 8.5 years of dietary intervention, breast cancer incidence and incidence of death as a result of breast cancer were lower in the dietary intervention group. During this period, death due to breast cancer occurred in 27 (0.016%) vs 61 women (0.024%), with a hazard ratio of 0.67 (95% confidence interval
After a cumulative median follow-up of 19.6 years and occurrence of a total of 3,374 breast cancers, the hazard ratio for breast cancer incidence for the intervention vs control group was 0.95 (95% CI = 0.89–1.02).
There was a significant reduction in death after breast cancer diagnosis in the dietary intervention group both during the intervention period and after a median 16-year follow-up. Death after breast cancer occurred in 359 (0.12%) vs 652 women (0.14%), with a hazard ratio of 0.85 (95% CI = 0.74–0.96, P = .01).
Conclusion
Adoption of a low animal fat high vegetable, fruit, and grain intake reduces the risk of death from breast cancer in postmenopausal women. Vegetables and grains have multiple anti-cancer effects. They contain healthy polyphenols, fibre, vitamins and minerals, plus they are less fattening than meat products and contain fewer carcinogens.