3 Extra Sodas Per Day Can Kill You Study shows that a "safe" diet is not so safe By Neal Colgrass, Newser Staff Posted Aug 13, 2013 4:18 PM CDT Updated Aug 17, 2013 1:20 PM CDT 162 comments Comments (Shutterstock) (Newser) – A steady diet of sodas could hinder your ability to reproduce or even shorten your life, if lab mice are any indication. Researchers at the University of Utah gave mice a diet of 25% sugar—equivalent to three extra sodas per day in people—and found the males less likely to reproduce or defend their territory, the Salt Lake Tribune reports. Females had it worse, dying at double their normal rate. And to think, the National Research Council tells us that this level of added sugar is considered safe in humans. "Added sugar consumed at concentrations currently considered safe exerts dramatic adverse impacts on mammalian health," the study says, according to Science Daily. Yet the mice weren't fatter and would have passed physicals, despite the negative health impacts—so the sugar's toxic damage is all "under the hood." Why rely on a study of mice? They're considered roughly equivalent to humans in dietary studies because they've had a similar diet to ours for about 10,000 years, and up to 80% of what's toxic to them is toxic to people, too.