A diet high in fat and in high fructose corn syrup may cause severe liver problems in people with a sedentary lifestyle, according to a study conducted by researchers from Saint Louis University and presented this year at the Digestive Diseases Week meeting in Washington, D.C.
Researchers fed mice a diet that was 40 percent fat and high in high fructose corn syrup for 16 weeks. In contrast to other studies, where mice have been fed a regulated amount, the animals in the study were allowed to eat as much as they wanted. They were kept sedentary and prevented from exercising.
"We wanted to mirror the kind of diet many Americans subsist on, so the high fat content is about the same you'd find in a typical McDonald's meal, and the high fructose corn syrup translates to about eight cans of soda a day in a human diet, which is not far off with what some people consume," said Brent Tetri, M.D., an associate professor of internal medicine at Saint Louis University Liver Center.
To the researchers' shock, it took only four weeks for the first signs of serious health problems to emerge.
"We had a feeling we'd see evidence of fatty liver disease by the end of the study," Tetri said. "But we were surprised to find how severe the damage was and how quickly it occurred. It took only four weeks for liver enzymes to increase and for glucose intolerance -- the beginning of Type 2 diabetes -- to begin."
According to Tetri, preliminary research suggests that fructose actually suppresses the body's feeling of fullness, whereas foods rich in fiber activate it. This meant that the mice didn't know when to stop eating, even though their diet was exceptionally high in calories.
High fructose corn syrup is a widely used sweetener, particularly in the United States, where corn is cheap and sugar importation is expensive.
"A high-fat and sugar-sweetened diet compounded by a sedentary lifestyle will have severe repercussions for your liver and other vital organs," Tetri warned.