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.
Medical experts in India agree.
"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
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
"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,
The study further concluded that no significant
association with soy food consumption was found for post-menopausal breast cancer.