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News Release

July 12, 2005

Researchers Developing Test to Determine Body Response to Dietary Fat

A University of Guelph nutritional scientist is working to develop tests to assess how individuals react to various fat types. Lindsay Robinson wants to know how different fats affect the body’s metabolic activities and the roles they may play in diseases such as type 2 diabetes.

“Fats can’t be placed in just one category, because they don’t all elicit the same response,” said Robinson, a professor in the Department of Human Health and Nutritional Sciences. “For example, polyunsaturated fats, or ‘good’ fats, have been shown to reduce cholesterol and risks for type 2 diabetes and cardiovascular disease when you eat them as a substitute for ‘bad’ fats, like saturated fat.”

Traditional fat tolerance tests used to assess how a person responds to dietary fat intake often lump all fat types together, but Robinson wants to compare “good” and “bad” fats because they each create different metabolic responses. She’s working with food scientists to design a shake-like drink containing selected natural fatty acids that can be used to test how humans metabolize different fat compositions. After study participants ingest the fat-rich drink, researchers can test lipid (e.g. triglycerides) levels in each subject’s blood and the metabolic response that is associated with the specific fat composition in the drink.

Robinson said it’s important to test different fat types separately to learn which are the most beneficial for health. Simply switching from so-called “bad” fats such as those found in butter, shortening and meat to “good” fats such as those in canola and olive oils can actually help reduce blood cholesterol and triglycerides, which can lead to improved health. Prevention and awareness are key to a healthier public and lower chronic disease risks, she said. Robinson and her team hope to learn more about the benefits of “good” fat and to help the food industry incorporate these fats into everyday foods to promote optimal human health.

She’s also interested in cytokines, hormone-like proteins that are involved in inflammatory responses. Cytokines, which are released from adipose (fat) tissue in the body, are believed to contribute to obesity-related chronic diseases, such as type 2 diabetes and cardiovascular disease, which means that people with excess adipose tissue could be at higher risk for those diseases.

The researchers are now testing to determine whether abnormally high cytokine levels result from fat ingestion and if the type of fat can alter the cytokine response. One of their criteria for whether a fat is “good” or “bad” is how it affects cytokine levels, among other metabolic responses. If a certain fat type leads to increased cytokine release, it might be one people should avoid. Abnormal metabolic responses to fat ingestion can occur many years before the actual onset of disease, making this information useful as an early biomarker of type 2 diabetes and cardiovascular disease.

Eventually, the research group hopes to develop a fat tolerance test to rapidly assess Canadians’ risk for type 2 diabetes and cardiovascular disease. Earlier risk detection means people will have more time to change their diet and lifestyle, helping to prevent these diseases.

Collaborating on this research are Prof. Terry Graham and Prof. Amanda Wright, Department of Human Health and Nutritional Sciences, and Prof. Alejandro Marangoni from the Department of Food Science.