A study shows that cooking oil consumption has worsened colon cancer and colitis in mice

Foods fried in vegetable oil are popular around the world, but research on the effects of this cooking technique on health has been inconclusive and focused on healthy people. For the first time, UMass Amherst food scientists undertook to examine, with the help of animal models, the impact of oil consumption. frying on inflammatory bowel diseases and colon cancer.

In their article published on August 23 in Cancer Prevention Research, lead author and Ph.D. student Jianan Zhang, associate professor Guodong Zhang and Professor and Department Head Eric Decker showed that feeding frying oil to mice exaggerated colonic inflammation, increased tumor growth and worsened intestinal leakage, spreading bacteria or toxic bacterial products into the blood.

"People with colon inflammation or colon cancer should be informed of this research," says Zhang Jianan.

Zhang Guodong, whose food science lab is focused on finding new cell targets in the treatment of colon cancer and on reducing the risk of IBD, points out that "this is not our message that the ITNs are doing." frying oil can cause cancer ".

The new research suggests instead that the consumption of fried foods can exacerbate and advance the conditions of the colon. "In the United States, many people have these diseases, but many of them can still eat fast food and fried foods," said Guodong Zhang. "If someone suffers from IBD or colon cancer and is eating that type of food, there is a chance that it will make the disease more aggressive."

For their experiments, the researchers used a sample of real world canola oil, in which falafel had been cooked at 325 F in a standard commercial fryer at a restaurant in Amherst, Massachusetts. "In America, canola oil is widely used for frying," said Zhang Jianan.

Decker, an expert in lipid chemistry, conducted the analysis of the oil, which undergoes a set of chemical reactions during the frying process. He characterized the fatty acid profiles, the level of free fatty acids and the state of oxidation.

A combination of frying oil and fresh oil was added to the powder diet of a group of mice. The control group was fed powdered diet with only fresh mixed oil. "We have tried to imitate the diet of the human being," said Zhang Guodong.

Supported by grants from the US Department of Agriculture, researchers examined the effects of diets on colonic inflammation, colon tumor growth, and intestinal leakage, concluding that the oil-based diet frying had aggravated all the conditions. "The tumors doubled in size from the control group to the study group," said Zhang Guodong.

To test the hypothesis that the oxidation of inflammatory acids by the oxidation of polyunsaturated fatty acids, which occurs when the oil is heated, is critical, the researchers isolated the polar compounds contained in the frying oil and then passed on to the mice. The results were "very similar" to those of the experiment in which the mice had been fed with cooking oil, suggesting that the polar compounds induced the inflammatory effects.

Although additional research is needed, the researchers hope that a better understanding of the effects of cooking oil on health will lead to dietary guidelines and public health policies.

"For people with inflammatory bowel diseases or prone to these diseases," says Zhang Guodong, "it's probably a good idea to eat less fried foods."