High soy intake during adolescence reduces the risk of breast cancer in the pre-menopausal years by about 25 to 50 percent, suggests a recent study.
Larissa Korde, principal researcher at the Clinical Genetics Branch Division of Cancer Epidemiology and Genetics, National Cancer Institute, US, in her report found that soy intake from childhood was significantly associated with reduced breast cancer risk.
Korde is an assistant professor in the University of Washington (UW) division of Medical Oncology.
"The rate of breast cancer has always increased or decreased with food habits. Breast cancer rates are high in western nations as compared to women living in China and Japan where people consume high soy diet since childhood," Sameer Kaul, senior consultant, oncology, at Apollo Hospital told IANS.
Soy protein is a high quality protein equivalent to the protein quality of egg, milk or meat. Soybean is a functional food of this millennium with complete protein package, containing essential amino acids that are required by the body.
With almost 40 percent protein, soybeans are higher in protein content than other legumes and numerous animal products.
According to the study, the isoflavone protein in soy inhibits the growth of cancer in men (prostate cancer) and women (breast cancer).
"Isoflavone in soybean acts like tamoxifen, a medicine which is used to cure breast cancer. Women with a high lifetime exposure to estrogen have greater risk of breast cancer. So, isoflavone exerts an anti-estrogen effect at some body tissues which may explain the reduced risk of breast cancer," said Anupama Hooda, chief of medical oncology at Max Health Care Superspeciality Hospital.
Hooda says that soy should be consumed from its natural sources - plant products like tofu and miso. Soya products like soy milk, soybean chunks, soy-flour, soy papad, soy cookies and soy namkeens can also be consumed instead of taking pills having high soy proteins.
Talking about the ill-effects of soy pills, Hooda said: "Isoflavones in the pill thickens the blood since they are processed and can bring about clumping red blood cells which is not a good sign."
"Consuming soy food consistently at an early age is always better than going for hormonal replacement therapy opted by women to remain young as it increases the period of menopause and also increases the risk of breast cancer," said Rohit V. Nayyar, senior consultant, oncology, Apollo Hospital.
The study further concluded that no significant association with soy food consumption was found for post-menopausal breast cancer.