Associations Between Immigrant Status and Dietary Patterns in ENCLAVE, A Pooled, Observational Study of Women Diagnosed With Breast Cancer.

Background: Diet, critical to breast cancer (BC) survivorship, may change with immigration.

Objective: We examined associations between immigration factors and diet in a large, diverse population of BC survivors.

Methods: The Exploring Networks in a Cohort of Latina and Asian Emigrants, lifestyle, and Vital status (ENCLAVE) study included harmonized, pooled data from 4882 Asian, Hispanic, and non-Hispanic White (NHW) women from 3 Northern California cohorts of women diagnosed from 1996 to 2013 with invasive BC and who provided data on immigrant status and diet. We conducted principal components analysis of data from food frequency questionnaires, which produced "prudent" and "Western" dietary patterns. Outcomes were tertiles characterizing the most healthful (i.e., highest prudent, lowest Western) patterns. Secondary outcomes included high intakes of fruits and vegetables (F&V) and soy and low intakes of red meat, high-fat dairy, and sweets. We fit log-binomial regression models to examine self-reported nativity and immigration-related variables (language preference, age at immigration, years in the United States, and second-generation status) and relative prevalence of dietary outcomes, overall and by race and ethnicity.

Results: The correlation between the prudent and Western patterns was r = -0.08, P < 0.001. Foreign-born women consumed higher prudent (prevalence ratio [PR] = 1.52; 95% CI: 1.38, 1.67) and lower Western (PR = 1.51; 95% CI: 1.37, 1.67) diets, as well as higher F&V, and lower butter and red meat intake, compared with United States-born women. Associations were similar by race and ethnicity, although we noted dietary heterogeneity for certain foods and by other immigration-related variables.

Conclusions: Foreign-born Asian, Hispanic, and NHW women with BC have healthier dietary patterns than United States-born women, overall and within same-race groups.