Cancer-Fighting Cows Graze Peacefully

April 10, 2000

Cows grazed on pasture or fed vegetable oil produce five times more of a cancer-fighting compound than cows fed conventional diets, says USDA’s Agricultural Research Service. The human body won’t produce the compound on its own but depends on whole milk, butter, beef and lamb to get the compound, known as conjugated linoleic acid (CLA).

CLA is a fatty acid found in beef and dairy fats. ARS dairy scientist Larry Satter added whole soybean and linseed oils to a typical corn-alfalfa diet, increasing the CLA content in the cow’s milk to equal the levels obtained from grazing. ARS and the Wisconsin Alumni Research Foundation patented the method to increase CLA is cows’ milk.

The studies may increase interest among producers to graze dairy cows. Now only 10-12% of dairy cows are grazed. A University of Wisconsin researcher is credited with discovering CLA’s cancer-fighting properties in a study of rats fed fried hamburger. Human studies now are underway at several research institutions.

Laboratory animals given CLA in their diets have shown a reduction in several types of cancers and a slower progression of atherosclerosis, a contributor to heart disease. If human trials show the same benefits as studies with laboratory animals, benefits from consuming milk products could have an impact on the economy of all dairy producers, ARS says.