Consuming the equivalent of three cans of soda on a daily basis, or a 25% increased added-sugar intake, may decrease lifespan and reduce the rate of reproduction, according to a study of mice published in the journal Nature Communications.
Researchers from the University of Utah conducted a toxicity experiment on 156 mice, of which 58 were male and 98 were female.
The experiment involved placing them in room-sized pens called "mouse barns" with a number of nest boxes. The researchers say this allowed the mice to move around naturally to find mates and explore the territories they wished.
The mice were fed a diet of a nutritious wheat-corn-soybean mix with vitamins and minerals. But one group of mice had 25% more sugar mixed with their food - half fructose and half glucose. Mice in a control group were fed corn starch in place of the added sugars.
The National Research Council recommends that people should have no more than 25% of their daily calories from foods and beverages with added sugar.
This study in mice suggests that consuming the equivalent of three extra sodas a day could decrease your length of life.
This is the equivalent of consuming three cans of sweetened soda a day alongside a healthy, no-added-sugar diet.
However, the US Centers for Disease Control and Prevention (CDC) issued a report this year revealing that around 13% of Americans' total daily calorie intake is from added-sugar sources.
Reduction in lifespan and mortality
Results of this most recent research showed that after 32 weeks in the mouse barns, 35% of the female mice who were fed the added-sugar foods died, compared with 17% of female mice fed the no-added-sugar diet.
Additionally, the results showed that male mice fed the added-sugar diet held 26% less territory compared with male mice who were fed the no-added-sugar diet.
The research also showed that male mice on the sugar diet produced 25% fewer offspring compared with the male mice in the control group.
However, the results reported no difference between the mice fed the healthy diet and those fed the added-sugar diet when looking at obesity, fasting insulin levels, fasting glucose levels and fasting triglyceride levels.
The study authors say of the findings:
"Our results provide evidence that added sugar consumed at concentrations currently considered safe exerts dramatic adverse impacts on mammalian health.
This demonstrates the adverse effects of added sugars at human-relevant levels."
The researchers add that the strength of this study is built on how the mice were tested in a natural environment they are accustomed to, providing more accurate results.
Wayne Potts, professor of biology at the University of Utah and the study's senior author, says:
"Mice happen to be an excellent mammal to model human dietary issues because they have been living on the same diet as we have ever since the agricultural revolution 10,000 years ago."
'Toxic compounds in foods need to be assessed'
There are many types of sugars added to food and beverages, particularly sweets, chocolate, sodas and some juice drinks. These may be listed in the forms of:
- Corn Syrup
- Hydrolyzed starch
- Invert sugar
The study's authors say that this research shows there is a need for "human-made toxic substances," like those listed above, to be assessed.
They say that "the need is particularly strong for pharmaceutical science, where 73% of drugs that pass pre-clinical trials fail due to safety concerns, and for toxicology, where shockingly few compounds receive critical or long-term toxicity testing."
Prof. Potts adds:
"Our test shows an adverse outcome from the added sugar diet that could not be detected by conventional tests. You have to ask why we did not discover them 20 years ago."
"The answer is that until now, we have not had a functional, broad and sensitive test to screen the potential toxic substances that are being released into the environment or in our drugs or our food supply."