New York City's quixotic ban on large sodas took aim at excess dietary sugar.
The ban's obvious flaws and air of overreach led to ridicule and a recent judicial reversal.
But a fast-mounting body of evidence affirms the idea that sugar is public health enemy number one.
Americans now consume 40 times more sugar than they did during the American Revolution of 1775-1783 (Bray GA 2013).
And just under half of the added sugars – sugar and high-fructose corn syrup (HFCS) – Americans consume come from soda and fruit drinks, which typically contain 28 grams per 8 oz serving (Bray GA 2013).
The intake of soft drinks rose five-fold between 1950 and 2000, and ample evidence links the diets high in sugar-sweetened drinks to a range of diseases.
Corn syrup vs. cane sugar:
Both sugars are equally bad in excess
Several clinical trials have compared the effects of sugary soft drinks versus low- or no-calorie drinks.
High-fructose corn syrup (HFCS) and cane sugar worsen key markers for impending ill health equally: blood triglycerides, body weight, visceral adipose tissue (belly fat), muscle fat, and liver fat.
American's sugar consumption has soared 50 percent since the 1970s, accompanied by dramatic rises in metabolic conditions such as diabetes, obesity, fatty liver, and cardiovascular disease.
Both high-fructose corn syrup (HFCS) and cane sugar (sucrose) consist of one molecule of fructose and one molecule of glucose.
Accordingly, repeated studies find no significant, consistent differences in how the body metabolizes or is affected by HFCS and cane sugar (Bray GA 2013).
Some of the harm attributed to excess sugars – but not all or most of it – is attributed to fructose, which the body metabolizes differently from glucose.
Mouse study adds reasons to avoid sugars
Mounting evidence indicates that excess sugar can promote dementia, cancer, obesity, diabetes, cardiovascular disease, and metabolic syndrome.
We've covered some of the relevant research in our newsletter … see our sidebar, “Sugar research reveals real risks” for links to those reports.
Now, a novel mouse study shows that a healthy diet plus the equivalent of three cans of soda daily doubled the females' death rate and rendered the males less likely to defend territory and reproduce.
According to lead author James Ruff, Ph.D., “We have shown that levels of sugar that people typically consume – and that are considered safe by regulatory agencies – impair the health of mice.” (UU 2013)
The experimental diet provided 25 percent of calories from added sugar – half fructose and half glucose – no matter how many calories the mice ate.
Senior author Wayne Potts said that the National Research Council recommends getting no more than 25 percent of calories from “added sugar.”
As he said, this means that the NRD doesn't “… count what's naturally in an apple, banana, potato or other non-processed food. The dose we selected [for this rat study] is consumed by 13 percent to 25 percent of Americans.” (UU 2013)
The diet fed to the mice with the 25 percent sugar-added diet is equivalent to a person drinking three cans daily of sweetened soda, “plus a perfectly healthy, no-sugar-added diet,” Potts added.
The mice were divided into two groups, each given a nutritious chow made of a wheat-corn-soybean mix plus vitamins and minerals:
- Test group: Chow + sugar equaling 25 percent of total dietary calories
- Control group: Chow + corn starch equaling 25 percent of total dietary calories
Frankly, it seems odd to use corn starch as a “placebo”, since the body converts its “simple” starches into sugars very rapidly.
Still, the study found that added sugar was much more harmful to mice, compared with an equal number of calories from corn starch.
Study put mice in a natural setting
Mice often live (uninvited) in people's homes and have done that for millennia.
So as Potts said, “mice happen to be an excellent mammal to model human dietary issues because they've been living on the same diet as we have ever since the agricultural revolution 10,000 years ago.”
Typical lab mice come from strains bred in captivity for decades. They lack the territoriality shown by wild mice.
Wisely, the study authors used mice descended from wild house mice that were “outbred” to prevent the inbreeding typical of lab mice.
“They are highly competitive over food, nesting sites and territories,” professor Potts said. “This competition demands high performance from their bodies, so if there is a defect in any physiological systems, they tend to do more poorly during high competition.”
The groundbreaking new toxicity test placed groups of mice in room-sized pens nicknamed “mouse barns” (Ruff JS et al. 2013).
This provided a much more realistic environment than small, typical lab cages, allowing the mice to compete more naturally for mates and territories, thereby revealing subtle effects on their performance.
“This is a sensitive test for health and vigor declines,” said Wayne Potts, the study's senior author.
As Dr. Ruff said, “When you look at a mouse in a cage, it's like trying to evaluate the performance of a car by turning it on in a garage. If it doesn't turn on, you've got a problem. But just because it does turn on, doesn't mean you don't have a problem.”
Added sugar impaired mouse lifespan, behavior, and reproduction
After 32 weeks, the outcomes proved damning for the effects of sugar:
- Twice as many of the females fed extra sugar died (35 percent vs. 17 percent of the control mice).
- Males on the added-sugar diet acquired and held 26 percent fewer territories than males on the control diet.
- Males on the added-sugar diet produced 25 percent fewer offspring than control males.
- The sugar-added females had lower reproductive rates as the study progressed, only partly because they had higher death rates.
- There was no difference in the death rates among males who did and did not get added sugar.
The researchers studied another group of mice to look for sugar-driven metabolic changes.
The only differences were minor, with the sugar-fed mice showing these ill effects:
- Cholesterol was elevated in all sugar-fed mice.
- The ability to clear glucose from the blood was impaired in female mice.
The study found no difference between the mice when it came to obesity, fasting insulin levels, fasting glucose or fasting triglycerides.
Results add reasons to minimize added sugar
The results of the Utah rat study provides more reasons to be wary of soda and other sources of added sugar.
But we've know that excess sugar is bad for a long time.
Evidence that sugary diets are far more dangerous to heart health than diets high in saturated fat and cholesterol dates back decades, and was detailed in William Dufty's popular 1975 book, Sugar Blues.
Back in 2009, the videotape of a lecture by UCLA professor Robert Lustig M.D. – “Sugar: The Bitter Truth
” – went viral.
Yet, all he'd done was to list and explain, in an entertaining way, existing evidence of the many ill effects of consuming the excess sugar typical of the standard American diet.
His UC colleague Fernando Gomez-Pinilla, Ph.D., published disturbing animal evidence that sugar harms brain health – and that this harm can be blunted by omega-3 fatty acids from fish – see “Sugary Brain Damage Blunted by Omega-3s
- Bray GA. Energy and fructose from beverages sweetened with sugar or high-fructose corn syrup pose a health risk for some people. Adv Nutr. 2013 Mar 1;4(2):220-5. doi: 10.3945/an.112.002816.
- Ruff JS, Suchy AK, Hugentobler SA, Sosa MM, Schwartz BL, Morrison LC, Gieng SH, Shigenaga MK, Potts WK. Human-relevant levels of added sugar consumption increase female mortality and lower male fitness in mice. Nat Commun. 2013 Aug 14;4:2245. doi: 10.1038/ncomms3245.
- University of Utah (UU). Sugar is Toxic to Mice in ‘Safe' Doses. Aug. 13, 2013. Accessed at http://unews.utah.edu/news_releases/sugar-is-toxic-to-mice-in-safe-doses/