Joint Association of High Cabbage/Sauerkraut Intake at 12-13 Years of Age and Adulthood with Reduced Breast Cancer Risk in Polish Migrant Women: Results from the US Component of the Polish Womenís Health Study (PWHS). * DR Pathak, JP He, J Charzewska (Michigan State University, E. Lansing, MI 48824 and University of New Mexico, Albuquerque, NM 87131, National Food and Nutrition Institute, Warsaw, PL)
Introduction: Cabbage is a member of Brassica vegetables which contain glucosinolates (GLS). The break-down products of GLS include indole-3-carbinol and its digestive derivative, 3,3í-diindolylmethane and isothiocyanates, all of which have been shown to have anti-carcinogenic properties both in vitro and in vivo studies. Consumption of cabbage and sauerkraut is high in Poland (30 lbs/year) relative to US (10lb/year). Polish migrant women to the US experience a tripling in breast cancer (BC) mortality, reaching in their lifetime the high rates observed for US-born women. We hypothesized that reduced consumption of cabbage/sauerkraut that follows acculturation could contribute to the increased risk of BC in Polish migrant women.
Methods: The PWHS is a case-control study of BC in Poland and Polish-born immigrants to the US**. Using a 143-item food frequency questionnaire, we ascertained food consumption for ages 12-13 years and during 1985-89, a period immediately prior to introduction of the market economy in Poland. Specifically we assessed consumption of cabbage foods that can be categorized as: raw salads (sauerkraut and fresh cabbage), short-cooked (sauerkraut as side dish and steamed cabbage), and long-cooked (hunterís stew, cabbage rolls, and pierogi).
Results: There was no association between case status and consumption of long-cooked cabbage foods. Results are based on analyses of raw and short-cooked cabbage foods, thus accounting for bioavailability of active compounds Consumption for both time periods was categorized as: low (L) ≤1.5, medium (M) =1.5-3, high (H) >3 servings/week). Conditional logistic regression was used with age/site (Chicago, Detroit) categories as strata. The odds ratios (ORs) are adjusted for energy intake, physical activity, reproductive history and hormone use. The OR for the joint effect of (adolescence, adulthood) of (H, H) consumption relative to the reference of (L, L) was OR=0.28, p<0.05. Similar effect was observed for the (H, M) and (H, L) consumption subgroups. For the medium consumers in adolescence a dose response was observed for the effect of adult consumption with (M, H) category, OR=0.27, p<0.05. For low consumers in adolescence a non-significant reduction in risk was observed for the (L, H) group, OR=0.37, p=0.15.
Discussion: Results from the US component of the PWHS provide epidemiological evidence for a significant decrease in BC risk with high intake of raw/short-cooked cabbage/sauerkraut during adolescence. The protective effect was present irrespective of the level of cabbage/sauerkraut consumption during adulthood. High consumption during adulthood continues to provide significant protective effect for women with medium or low consumption during adolescence. This pattern of risk reduction indicates that breakdown products of glucosinolates in cabbage foods may affect both the initiation phase of carcinogenesis, by decreasing the number of initiated cells, and the promotion phase, by blocking the processes that inhibit apoptosis and stimulate cell growth. Therefore, increased consumption of cabbage/sauerkraut foods in adolescence and adulthood may be an important primary prevention for breast cancer.