Dietary fat and breast cancer mortality: A systematic review and meta-analysis

ABSTRACT

Background: The influence of dietary fat upon breast cancer mortality remains largely understudied despite extensive investigation into its influence upon breast cancer risk. Objective: To conduct meta-analyses of studies to clarify the association between dietary fat and breast cancer mortality. Design: MEDLINE and EMBASE were searched for relevant articles published up to March 2012. Risk of all-cause or breast-cancer-specific death was evaluated by combining multivariable adjusted estimates comparing highest versus lowest categories of intake; and per 20 g increase in intake of total and/or saturated fat (g/day) using random-effects meta-analyses. Results: Fifteen prospective cohort studies investigating total fat and/or saturated fat intake (g/day) and breast cancer mortality were included. There was no difference in risk of breast-cancer-specific death (n = 6; HR = 1.14; 95% CI: 0.86, 1.52; p = 0.34) or all-cause death (n = 4; HR = 1.73; 95% CI: 0.82, 3.66; p = 0.15) for women in the highest versus lowest category of total fat intake. Breast-cancer-specific death (n = 4; HR = 1.51; 95% CI: 1.09, 2.09; p < 0.01) was higher for women in the highest versus lowest category of saturated fat intake. Conclusions: These meta-analyses have shown that saturated fat intake negatively impacts upon breast cancer survival.

Keywords:

• Dietary fat
• saturated fat
• breast cancer survival

Acknowledgments

Authors' responsibilities: SFB and PML conducted the literature search and SFB, JVW, MMC, and CRC extracted the data. CRC, JVW, and MMC conducted the statistical analysis. SFB prepared the first draft of the article. SFB, JVW, PML, CRC, and MMC contributed to the writing, editing, and proofreading of the final version of the article. No conflicts of interest were declared.

Funding

SFB was funded by a PhD studentship from the Department of Employment and Learning, Northern Ireland.