May 9, 2013
Diets Rich In Soy And Tomato Could Help Prevent Prostate Cancer
redOrbit Staff & Wire Reports - Your Universe Online
Eating tomatoes and soy together could be better at preventing prostate cancer than consuming either food product by itself, according to new research published online in the journal Cancer Prevention Research.
“In our study, we used mice that were genetically engineered to develop an aggressive form of prostate cancer,” John Erdman, a professor of food science and nutrition at the University of Illinois and one of the study authors, said in a statement.
“Even so, half the animals that had consumed tomato and soy had no cancerous lesions in the prostate at study's end,” he added. “All the mice in the control group — no soy, no tomato — developed the disease.”
According to the researchers, the mice were fed one of four different diets from the time they were four weeks old until they were 18 weeks old — a time frame chosen to model early and lifelong exposure to the bioactive components contained within those foods, Erdman explained.
The first group ate 10 percent whole tomato powder while the second consumed two percent soy germ. The third group was given both tomato powder and soy germ, while the fourth was a control group that was given neither substance. The researchers then measured the success of each diet at helping to prevent prostate cancer.
“Eating tomato, soy, and the combination all significantly reduced prostate cancer incidence,” Erdman said. “But the combination gave us the best results. Only 45 percent of mice fed both foods developed the disease compared to 61 percent in the tomato group, and 66 percent in the soy group.”
While prostate cancer is the most frequently diagnosed form of the disease in men, it has a nearly 100 percent survival rate provided it is detected early enough, the researchers said. It tends to be a slow-growing cancer in older men, and they often choose waiting over surgery and radiation, both of which could have side effects.
The soy isoflavone serum and prostate levels of the rodents are said to be similar to those found in Asian men who consume between one to two servings of the legume each day. In countries where soy is consumed daily, Erdman said that prostate cancer occurs at significantly lower levels — and the findings of the research suggest that soy and tomato could help men who are concerned about their prostate health.
“The results of the mouse study suggest that three to four servings of tomato products per week and one to two servings of soy foods daily could protect against prostate cancer," said study co-author Krystle Zuniga.
“It's better to eat a whole tomato than to take a lycopene supplement. It's better to drink soy milk than to take soy isoflavones,” Erdman added. “When you eat whole foods, you expose yourself to the entire array of cancer-fighting, bioactive components in these foods.”