Soy, Whey Proteins May Lower Cancer Risk
NEW YORK (Reuters Health) - Consuming a diet rich in soy and whey protein may help women lower their risk of developing breast cancer, results of a study in rats suggest.
The findings, although preliminary, add weight to a growing body of evidence supporting a link between diet and cancer.
"These results suggest diets containing these commonly consumed protein sources have great potential in reducing the risks of breast cancer," report Dr. Reza Hakkak and colleagues with the Arkansas Children's Nutrition Center in Little Rock.
The investigators looked at chemically induced mammary tumors in rats fed a diet containing casein, a major milk protein; whey, a minor milk protein; or soy, a plant-derived protein found in tofu, tempeh, soybeans and several other foods.
As expected, all of the rats fed a diet containing casein as the only source of protein developed mammary tumors. However, only 77% of rats in the soy group developed one or more tumors and about 54% of rats in the whey group developed at least one mammary tumor.
Overall, the study found that soy protein decreased the incidence of mammary tumors by about 20% and whey protein was about twice as effective as soy in reducing the incidence and number of tumors. The results are published in the January issue of Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.
"This significant new research, although preliminary, suggests that adding whey or soy protein to the diet may help protect women and children from developing breast cancer," said Dan Glickman, secretary of the US Department of Agriculture, the organization that funded the study.
The mechanisms by which whey and soy protein appears to lower breast cancer risk are not clear, however. The study authors note that rates of breast cancer in Asia, where people consume diets rich in soy protein, are about 10% lower than in the US. What's more, rates of cancer increase in the second generation of families that migrate to the US and consume a typically American diet.
While other components of the Asian diet may contribute to lower rates of cancer and specifically breast cancer, "factors found in soybeans have been reported to provide important protection against initiation, promotion, or progression of breast cancer in animal models," Hakkak and colleagues write.
Cancer, Epidemiology, Biomarkers and Prevention 2000;9.
Copyright 2000 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.
NEW YORK (Reuters Health) - Consuming a diet rich in soy and whey protein may help women lower their risk of developing breast cancer, results of a study in rats suggest.
The findings, although preliminary, add weight to a growing body of evidence supporting a link between diet and cancer.
"These results suggest diets containing these commonly consumed protein sources have great potential in reducing the risks of breast cancer," report Dr. Reza Hakkak and colleagues with the Arkansas Children's Nutrition Center in Little Rock.
The investigators looked at chemically induced mammary tumors in rats fed a diet containing casein, a major milk protein; whey, a minor milk protein; or soy, a plant-derived protein found in tofu, tempeh, soybeans and several other foods.
As expected, all of the rats fed a diet containing casein as the only source of protein developed mammary tumors. However, only 77% of rats in the soy group developed one or more tumors and about 54% of rats in the whey group developed at least one mammary tumor.
Overall, the study found that soy protein decreased the incidence of mammary tumors by about 20% and whey protein was about twice as effective as soy in reducing the incidence and number of tumors. The results are published in the January issue of Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.
"This significant new research, although preliminary, suggests that adding whey or soy protein to the diet may help protect women and children from developing breast cancer," said Dan Glickman, secretary of the US Department of Agriculture, the organization that funded the study.
The mechanisms by which whey and soy protein appears to lower breast cancer risk are not clear, however. The study authors note that rates of breast cancer in Asia, where people consume diets rich in soy protein, are about 10% lower than in the US. What's more, rates of cancer increase in the second generation of families that migrate to the US and consume a typically American diet.
While other components of the Asian diet may contribute to lower rates of cancer and specifically breast cancer, "factors found in soybeans have been reported to provide important protection against initiation, promotion, or progression of breast cancer in animal models," Hakkak and colleagues write.
Cancer, Epidemiology, Biomarkers and Prevention 2000;9.
Copyright 2000 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.