Can cheeseburgers fight cancer?

There's a flip side to the cheeseburger's reputation as a greasy, artery-clogging, cancer-causing meal. It is a prime source of a cancer-fighting compound.

Research by Martha Belury, assistant professor of foods and nutrition, Purdue University, found that a polyunsaturated fatty acid called conjugated dienoic linoleic acid (CLA) can inhibit skin cancer in mice. She also discovered that it can inhibit skin cancer during more than one of the three stages of disease development.

CLA is present in ruminant meat, cheese, and processed cheese. Some exists in milk and yogurt, less in poultry, eggs, and corn oil. Heating food - like pan - frying meat or pasteurizing milk - increases the CLA content.

Most cancer-fighting compounds that have been found in food affect only one organ, such as the stomach, skin, or colon, Belury says. "The fact that CLA protects against stomach, mammary, and skin cancers makes it unique. It's an indicator that something is going on here." That "something" is a puzzle with several pieces still missing. Belury added yet another puzzle piece when she found that CLA inhibits cancer during more than one of its three stages of development - initiation, when a cell or cells are genetically damaged to become precancerous; promotion, when precancerous cells multiply to form tumors; and progression, when tumors enlarge and spread to other organs.

Belury still doesn't know if CLA will work against cancer in people, but she argues that results of current tests warrant human clinical trials. If it does fight cancer in humans, CLA easily might be worked into people's diets, because it doesn't take huge doses to have an effect.

She stresses that her findings don't contradict the National Cancer Institute's recommendation that people cut down on total fat intake. it still is important to reduce tat intake because diet does affect people's chances of developing health problems such as heart disease and cancer. Epidemiologists estimate that diet is a contributing factor in 35%. of cancer deaths in the U.S. However, Belury and others have found that the relationship between dietary fat and cancer isn't simple and one-sided.