Low-Fat Diet Reduced Risk of Death From Breast Cancer in Randomized Trial

A low-fat dietary intervention reduced the risk of dying from breast cancer among postmenopausal women without a prior diagnosis of breast cancer, according to the results of the prospective, randomized Women’s Health Initiative clinical trial (ClinicalTrials.gov identifier: NCT00000611). The trial results will be reported at the upcoming 2019 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.¹

The trial included 48,835 postmenopausal women aged between 50 and 79 years from 40 clinical centers in the United States. Eligible women had no prior diagnosis of breast cancer, a normal mammogram, and a daily fat consumption of least 32%. At baseline, women on the trial had an average age of 62 years and an average body mass index of 28; the majority of women were white (81%).

Between 1993 and 1998, women were randomly assigned to either the dietary intervention group (19,541 women) or the control group (29,294 women). Those in the dietary intervention group participated in a low-fat diet with increased servings of fruits, vegetables, and grains, and those in the control group continued their normal diet. The target daily fat consumption was 20% for the dietary intervention group, but most did not achieve this, having a daily fat consumption of 25%.

Women participated in the dietary intervention for a median of 8.5 years, and at a median of 19.6 years of follow-up, 3374 cases of breast cancer were diagnosed. The low-fat dietary intervention group had a 21% reduced risk of dying from breast cancer compared with the control group (hazard ratio [HR], 0.79; 95% CI, 0.64-0.97; P =.025).

“To our review, this is the only study providing randomized clinical trial evidence that an intervention can reduce a woman’s risk of dying from breast cancer,” wrote the primary study author Rowan Chlebowski, MD, PhD, FASCO, from the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center in Torrance, California, during a press conference prior to the meeting.²

References

1. Chlebowski RT, Aragaki AK, Anderson GL, et al. Low-fat dietary pattern and long-term breast cancer incidence and mortality: The Women’s Health Initiative randomized clinical trial. Poster presented at: 2019 American Society of Clinical Oncology Annual Meeting; Chicago, IL; May 31-June 4, 2019. Abstract 520.
2. American Society of Clinical Oncology (ASCO). Balanced, low-fat diet reduces risk of death from breast cancer in postmenopausal women. Published May 15, 2019. Accessed May 23, 2019.

This article originally appeared on Cancer Therapy Advisor