"Our results provide evidence that added sugar consumed at concentrations currently considered safe exerts dramatic adverse impacts on mammalian health," the researchers say in a study set for online publication Tuesday, Aug. 13 in the journal Nature Communications. The increased rates of mortality and decreased reproduction observed in this study represent the lowest level of added sugar consumption shown to adversely affect mammalian health. The study says the need for a sensitive toxicity test exists not only for components of our diet, but "is particularly strong for both pharmaceutical science, where 73 percent of drugs that pass preclinical trials fail due to safety concerns, and for toxicology, where shockingly few compounds receive critical or long-term toxicity testing." Third, our F/G diet was based on a modified chow and not a refined diet, meaning that our F/G-fed animals showed impairment despite having the remainder of their diet being highly nutritive, whole grain-based, with optimum mineral and vitamin composition, analogous to human subjects consuming a healthy diet plus the equivalent of ≈3 cans (354 ml each) of soda per day. We detected substantial adverse outcomes due to an added sugar exposure consisting of a 1:1 ratio of fructose and glucose amounting to 25% kcal. The Findings: Added Sugar Impairs Mouse Lifespan and Reproduction 
 
 -- After 32 weeks in mouse barns, 35 percent of the females fed extra sugar died, twice the 17 percent death rate for female control mice. Though death rates of males were higher than females due to intra-sexual competition, they did not differ between dietary groups. Given that the energetic allocation toward offspring is much higher for females than for males it is not surprising that females might incur increased mortality due to a nutritional manipulation, while males would be more likely to decrease reproductive output. The sugar-added females had higher reproduction rates than controls initially -- likely because the sugar gave them extra energy to handle the burden of pregnancy -- but then had lower reproductive rates as the study progressed, partly because they had higher death rates linked to sugar. The only pre-OPA fasting plasma measure that was associated with the decreased reproduction and increased mortality exhibited by F/G-fed animals was total cholesterol, as no difference was seen in plasma glucose, insulin or triglyceride concentrations.
– 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.