sealPurdue News

September 1996

Even just chewing the fat is a health risk, study finds

WEST LAFAYETTE, Ind. -- Fat in food doesn't even have to be swallowed to have a harmful effect on the body, a new study has found.

The study, by Richard Mattes, associate professor of foods and nutrition at Purdue University, found that people who just tasted fat, but didn't swallow it, had increased levels of triglycerides in their bodies. Elevated levels of triglycerides in the bloodstream are a risk factor for cardiovascular disease. High levels of triglycerides put people at high risk of having arteriosclerosis, or hardening of the arteries, which can lead to heart attacks.

"The study indicates that consumers may realize a previously unrecognized benefit from eating products containing fat substitutes," Mattes says. "Fat substitutes not only reduce the total fat consumed and calorie intake while maintaining the appeal of foods, they may also prevent an undesirable change in blood fat levels."

At this point, Mattes says he can only speculate on how this change in the body takes place.

In the study, 15 adults were exposed to four treatments in random order: They were given crackers topped with regular cream cheese, crackers topped with fat-free cream cheese, plain crackers or nothing. After they had chewed the snack for a few moments, they were asked to spit it out without swallowing.

All of the people in the study were given 50 grams of safflower oil in capsules (so that they could not taste it) before they were given the crackers, to mimic the fat intake of a real-life eating situation.

Triglyceride levels of people who had chewed the full-fat cream cheese almost doubled compared to the triglyceride levels of people exposed to the other three treatments.

Participants could not detect a difference between the full-fat and non-fat cream cheese, and weren't told which one they were eating. "It is unlikely that sensory or cognitive cues account for the effect," Mattes says.

"Fats themselves are tasteless. The dogma in the food industry has been that fats are perceived only through their texture, or 'mouth feel,' as it is called in the industry. However, our work suggests that there may be a chemical detection system for fats in the mouth.

"It seems that some chemical feature of the fat may provide the cue for the effect, but what that feature is and what level of fat is required will be issues that will have to be addressed in future studies.

"A better understanding of the mechanisms by which fats are sensed should facilitate the development of improved reduced-fat foods."

This study also presents several new questions for food and nutrition scientists.

"For one thing, current fat substitutes on the market are either carbohydrate-based; protein-based, such as Simplesse; or fat-based, such as Olestra," he says. "In this study we used a protein-based fat substitute. Will different types of fat substitutes -- especially fat-based substitutes -- elicit the same response? We are pursuing this question now."

Source: Richard Mattes, (765) 494-0662; Internet,
Writer: Steve Tally, (765) 494-9809; Internet,
Purdue News Service: (765) 494-2096; e-mail,

NOTE TO JOURNALISTS: The citation for the journal article mentioned in the news story is Am J Clin Nutr 1996; 63:911-7. Copies are available from Steve Tally, (765) 494-9809.

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