Cabbage and Sauerkraut Consumption in Adolescence and Adulthood and Breast Cancer Risk among US-Resident Polish Migrant Women

Background: Breast cancer (BC) incidence and mortality are lower in Poland than in the United States (US). However, Polish-born migrant women to US approach the higher BC mortality rates of US women. We evaluated the association between consumption of cabbage/sauerkraut foods and BC risk in Polish-born migrants to US. Methods: We conducted a case-control study of BC among Polish-born migrants in Cook County and the Detroit Metropolitan Area. Cases (n = 131) were 20-79 years old with histological/cytological confirmation of invasive BC. Population-based controls (n = 284) were frequency matched to cases on age and residence. Food frequency questionnaires assessed diet during adulthood and age 12-13 years. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated with conditional logistic regression. Consumption of total, raw/short-cooked, and long-cooked cabbage/sauerkraut foods was categorized as low, medium, or high (frequency of servings/week). Results: Higher consumption of total and raw/short-cooked cabbage/sauerkraut foods, during both adolescence and adulthood, was associated with a significantly lower BC risk. Consumption of long-cooked cabbage/sauerkraut foods was low and not significantly associated with risk. The multivariate OR for total cabbage/sauerkraut consumption, high vs. low (> 4 vs. <= 2 servings/week) during adolescence was 0.36 (95% CI = 0.18-0.71, p(trend) < 0.01) and 0.50 (95% CI = 0.23-1.06, p(trend) = 0.08) during adulthood. For raw/short-cooked cabbage/sauerkraut (> 3 vs.<= 1.5 servings/week), the ORs were 0.35 (95% CI = 0.16-0.72, p(trend) < 0.01) during adolescence and 0.37 (95% CI = 0.17-0.78, p(trend) < 0.01) during adulthood. For joint adolescent/adult consumption of raw/short-cooked cabbage/sauerkraut foods, (high, high) vs. (low, low), the OR was 0.23 (95% CI = 0.07-0.65). The significant association for high adolescent consumption of raw/short-cooked cabbage/sauerkraut foods and reduced BC risk was consistent across all levels of consumption in adulthood. Conclusion: Greater consumption of total and raw/short-cooked cabbage/sauerkraut foods either during adolescence or adulthood was associated with significantly reduced BC risk among Polish migrant women. These findings contribute to the growing literature suggesting a protective effect of a potentially modifiable factor, cruciferous vegetable intake, on breast cancer risk.