Sugar isn’t exactly a health food, but researchers say it could be toxic — at least to mice — and that’s not good news for people.
Mice who were fed a diet containing 25% sugar — the equivalent of a healthy human diet along with three cans of soda daily — were twice as likely to die by the end of the 58 week long study conducted at the University of Utah as mice fed a similar diet without the added sugar. The findings, published in the journal Nature Communications, suggest that even safe levels of sugar could have serious negative effects on people’s health.
While the mice did not show any symptoms of metabolic diseases, including obesity or high blood pressure, the male mice were 26% less territorial and produced 25% fewer offspring than the other mice. Those trends, say the scientists, hint that the sugar was having some biological effects that weren’t necessarily detectable in measures like weight gain.
“The [mice] are having fewer offspring because they are having a hard time competing, they’re less effective at foraging and raising young. That is due to lots of perturbations across their physiology. Since most substances that are toxic in mice are also toxic in people, it’s likely that those underlying physical problems that cause those mice to have increased mortality are at play in people,” says study author James Ruff of the University of Utah. “That doesn’t mean that the read-out we are going to get in people is reduced mortality. But that underlying damage is likely to be there.”
That’s the message that nutrition experts have been trying to convey to the sugar-loving American public — that sugar can not only contribute to overweight and obesity, but also drive physiological changes that can compromise health and even shorten lives. Dr. Robert Lustig, a pediatric endocrinologist at the University of California, San Francisco notes in his popular presentation, Sugar: The Bitter Truth that both table sugar and high fructose corn syrup cause the body harm, and they should be considered as dangerous as cigarettes and alcohol. And there is data to support his position. A February study published in the journal PLoS One, for example, linked higher sugar consumption with an increased risk of diabetes, and a 2012 study in the journal Circulation found that sugary beverages raised the risk of heart problems in men.
Some scientists note, however, that different types of sugar may have different effects on the body. High fructose corn syrup, for instance, can lead to fatty build-up in the liver that sets off a chain of metabolic effects that can increase the risk of heart disease and insulin resistance. But some research suggests that people don’t eat as much high fructose syrup in its purest form, which can cause the most health harms, as nutritionists thought.
Ruff and his team agree that researchers need to look more carefully at doses that are closer to what people actually consume. “We hope that other labs and scientists turn their attention to these low does so we can figure out exactly what is going on with these right. Right now, scientists are characterizing responses at doses that are much higher,” he says.
Even so, nutrition data shows that Americans are eating significantly greater amounts of sugar than we have in the past. Some estimates suggest the average U. S. adult now downs 50% more than adults in the 1970s. Still, since sugar in all its forms is so prevalent in the American food environment, cutting it out completely may be difficult, not to mention impractical. But, as Lustig suggests, eating more low-sugar foods like fruits and vegetables and whole grains could help to keep our collective sweet tooth in check.