(P13-039-25) Characterization of Plant-Based Dietary Patterns and Their Association With Total Cancer Risk in Postmenopausal Women: Insights From the Women’s Health Initiative

Objectives: This study employed a novel approach to characterize subtypes of plant-based dietary patterns and evaluated whether certain clusters were associated with cancer risk among postmenopausal women.

Methods: 824 postmenopausal women enrolled in the larger WHI Observational Study, who were cancer-free and reported no meat or poultry consumption in the preceding three months (i.e. non-meat eaters) at baseline (Between 1993 and 1998) were included in this study. A synthetic group of 825 participants representing meat eaters was generated and used as the comparison group in the Cox proportional hazards models. Dietary intake for all participants was assessed based on the validated food frequency questionnaire. Within the non-meat eater group, dietary patterns were derived using principal component analysis (PCA) followed by k-means clustering. Cox proportional hazards models evaluated the associations between dietary patterns and the risks of total breast or colorectal cancer, adjusting for sociodemographic, lifestyle, and clinical factors.

Results: A total of 65 breast or colorectal cancer cases were observed among the non-meat eaters, compared to 92 breast or colorectal cancer cases in the synthetic meat-eater group. Among the non-meat eater group, three distinct plant-based dietary patterns were identified: High Dairy and Solid Fat, High fish and alcohol consumption, High Fruit and Vegetable intake. Cox proportional hazards models demonstrated no statistically significant associations between these dietary patterns and total breast or colorectal cancer risk.

Conclusions: This study identified three distinct plant-based dietary patterns among postmenopausal women in the WHI Observational Study, but no significant associations were observed between these dietary patterns and total breast or colorectal cancer risk. The lack of significant findings for dietary patterns may be due to the small sample size of non-meat eaters and limited statistical power.

Funding Sources: This research was supported by the National Cancer Institute of the NIH under award number T32 CA092408. The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services through contracts HHSN268201600018C, HHSN268201600001C, HHSN268201600002C, HHSN268201600003C, and HHSN268201600004C.