Chemical composition and mammary cancer inhibitory activity of dry bean
The global economic burden caused by chronic diseases such as diabetes, heart disease, and cancer is enormous. Little information exists about the role that specific crops in the diet play to reduce these diseases. To address this question, the phenolic and flavonoid contents, oxygen radical absorbance capacity (ORAC), and anticancer activity of six market classes of dry bean (Phaseolus vulgaris L.) were evaluated. Cooked dry bean powder from two crop years were fed to laboratory rats to determine if bean had an effect on chemically induced mammary carcinogenesis compared to the standard diet in a preclinical model for breast cancer. Dry beans in the diet reduced cancer incidence (no. of animals with cancerous tumor) from 95% in the control to 67% in animals fed bean, and mean multiplicity (no. of cancer tumors per animal) from 3.23 to 1.46, respectively (both P 0.001). Dry bean market classes differed for cancer multiplicity (white kidney vs. navy, 1.05 vs. 1.87 tumors per animal, P = 0.004), but anticancer activity was not associated with ORAC, phenolic or flavonoid content, seed coat color, or nutrient content. Dry bean market classes from the Andean center of domestication (COD) reduced cancer multiplicity more than those from the Middle American COD (P = 0.02), and dry beans from race Nueva Granada were more protective than those from race Mesoamerican (P = 0.01).