CORVALLIS - Ongoing studies at Oregon State University of possible cancer prevention benefits from eating yogurt have led to the discovery of a compound in this popular dairy product that is anti-mutagenic and may be anti-carcinogenic.
Researchers presented their latest findings from this project at the recent annual meeting of the American Dairy Science Association.
Alan Bakalinsky, an associate professor in the OSU Department of Food Science and Technology, led a team of scientists that isolated palmitic acid as the beneficial component by chemically separating yogurt into its basic parts and testing each individually.
"Initially we were surprised to find that it was palmitic acid that appeared to be anti-mutagenic because this fatty acid is found in many foods including other dairy products and meats," said Bakalinsky. "However, consumption of these other foods has not been associated with a lowered risk for colon or other cancers."
A mutagen is a chemical or other agent that attacks and damages DNA. Sometimes, this damage can be the initiating event in cancer development. An anti-mutagenic compound prevents the mutagen from damaging DNA.
According to Bakalinsky, how the body absorbs palmitic acid may be the key to its anti-mutagenic properties.
"Further analysis revealed that palmitic acid occurs in a slightly different state in milk than in yogurt," Bakalinsky said. "In yogurt, palmitic acid occurs to a greater extent in the form of a free fatty acid, which is caused by the fermentation process that produces yogurt.
"The fermentation appears to partially alter the molecular structure of some of the components commonly found in milk," said Bakalinsky. "This change doesn't affect the amount of palmitic acid in the product. However, it does result in yogurt containing about 50 percent more free fatty acids of the palmitic type than are found in milk.
"It seems plausible that perhaps the body absorbs these free fatty acids in a way that allows them to express their anti-mutagenic characteristics," Bakalinsky added. The researcher said that he is planning to conduct an animal study to explore this possibility.
"Once more is known about this, the next step will be to set up a feeding study in which the anti-carcinogenic effects of palmitic acid can be evaluated," Bakalinsky said.
The health benefits of consuming yogurt have been rumored for many years, and some scientific papers have been published with evidence for these benefits.
"There have been some animal studies in recent years that show a strong possibility that something in yogurt is anti-carcinogenic," said Bakalinsky. Based on that evidence, Bakalinsky began a research program in 1993 aimed at identifying the anti-cancer compound or compounds in yogurt. If palmitic acid is proven to be an anti-carcinogenic compound, researchers hope to learn how the benefits of this chemical may be exploited in other foods.