Tomatoes Plus Soy May Reduce Risk of Prostate Cancer
AICR’s expert report and its updates concluded that tomatoes and other food containing lycopene lower the risk of prostate cancer. And lab research points to the prostate cancer-preventive actions of soy and its constituents.
A new animal study now suggests that tomatoes and soy in combination may be even more protective against prostate cancer than each food consumed separately.
The study was published online in Cancer Prevention Research.
Study researchers used a type of mice genetically engineered to develop an aggressive form of prostate cancer. Researchers placed the mice into four groups: one group ate a diet containing whole tomato powder; another group's diet contained soy germ; a third group ate a diet containing both tomato powder and soy germ; and a fourth control group consumed a conventional diet, without soy or tomato. Soy germ, just like wheat germ, is the reproductive part of the soy that germinates to grow into a plant.
The mice ate the assigned diet from 4 to 18 weeks old which, according to the authors, is the period of time that reflects early and lifelong exposure to the foods. At the end of the study, almost half of the mice (45 percent) consuming a combination of soy and tomato were free of prostate cancer compared to the mice that did not eat soy or tomato. Approximately one-third of the animals in each the tomato-eating group and the soy germ group had reduced incidence of prostate tumors. All of the mice in the control group developed the disease.
The researchers emphasize that their findings support AICR and the government’s dietary recommendations that a healthy cancer-protective diets consists of eating a variety of fruits and vegetables.
Source: Zuniga K, Clinton SK, Erdman JW Jr.meena Batada et al. "The interactions of dietary tomato powder and soy germ on prostate carcinogenesis in the TRAMP model. Cancer Prev Res. 2013 Apr 16.