LOS ANGELES — When mice were fed a diet that was 25 percent added sugars — an amount consumed by many humans — the females died at twice the normal rate and the males were less likely to reproduce and hold territory, scientists said in a report published Tuesday.
The study found “that added sugar consumed at concentrations currently considered safe exerts dramatic impacts on mammalian health,” the researchers said in the report, published in the journal Nature Communications.
“Many researchers have already made calls for re-evaluation of these safe levels of consumption,” the researchers said.
The report’s senior author, University of Utah biology professor Wayne Potts, said earlier studies fed mice sugars at levels higher than people consume in soft drinks, cookies, candy and other foods. The current study stuck to the levels consumed by human beings.
The scientists fed the mice a diet that got its added sugars from half fructose and half glucose monosaccharides, which is about what is found in high fructose corn syrup (HFCS), Potts said.
The study, he said, was not set up to differentiate between the effects of different forms of caloric sweeteners.
The Corn Refiners Association, a trade group, questioned the use of mice in the study, saying that the only way to know the effect in people would be to test people.
“Mice do not eat sugar as a part of their normal diet, so the authors are measuring a contrived overload effect that might not be present had the rodents adapted to sugar intake over time,” the group said in a statement.
The trade group for the sugar industry, the Sugar Association, said it was studying the research. But it maintained that the sweetener used in the study was crucial.
“Sugar and the various formulations of HFCS are molecularly different — they are not the same product, yet too often, and erroneously, HFCS is referred to as an ‘added sugar,’ ” the statement said. “Only sugar is sugar.”
Potts said mice were “an excellent mammal to model human dietary issues” because they have been living with people and eating the same food for thousands of years.
The Utah researchers noted that consumption of added sugars increased in the American diet by 50 percent from the 1970s to about 2008, primarily because of the higher consumption of HFCS.
The intake has since been declining, however, and the Sugar Association said consumption of sucrose has decreased by 35 percent in the past four decades.
The 2010 Dietary Guidelines for Americans advise people to limit their total intake of added sugars, fats and other “discretionary calories” to 5 percent to 15 percent of the total calories consumed every day.
The national Centers for Disease Control and Prevention found that from 2005 to 2010, Americans got 13 percent of their calories from added sugar.
The male mice in the study controlled 26 percent fewer territories and produced 25 percent fewer offspring, the scientists said.
The lower reproduction levels could be the result of a decreased ability to defend their territories, the researchers said. The diet did not affect weight.