Proteins "whey" in against free radicals - Prostate Cancer

USA Today (Society for the Advancement of Education), Feb, 2004

Whey, a liquid by-product from cheese production, may play a role in helping prevent prostate cancer. When Ohio State University, Columbus, food scientists treated human prostate cells in the lab with whey protein, cellular levels of the antioxidant glutathione increased up to 64%. Antioxidants such as glutathione have been shown to control cancer-causing free radicals.

"The buildup of free radicals is associated with the onset of many chronic illnesses, such as heart disease and cancer," notes Joshua Bomser, assistant professor of food science and technology. "And human prostate tissue is particularly susceptible to oxidative stress. In diseases like cancer, there's usually a reduction in the body's overall capacity to deal with oxidative stress. Keeping antioxidant levels elevated through diet and supplementation may prevent the development of chronic disease."

The researchers treated another batch of prostate cells with casein, the major protein found in cheese. Casein does not contain the key ingredient for manufacturing the antioxidant, and, as expected, glutathione levels in these cells did not increase. "Unlike casein, whey proteins are rich in cysteine, an amino acid that increases glutathione in the prostate," maintains Kyle Kent, a Department of Food Science graduate student. "Cheese contains various proteins that can influence the levels of different antioxidants in prostate cells. But cysteine is the amino acid that helps create healthy glutathione levels in the prostate, and glutathione helps keep free radicals under control."

The researchers caution that simply eating cheese will not ensure an increase in glutathione levels, because cysteine is contained in the whey that is separated from cheese early in the cheese-making process. Cysteine, however, also is found in foods such as poultry, wheat, broccoli, and eggs.