For a while now, debates have been raging about artificial sweeteners and sugar substitutes. As ubiquitous as Splenda, Equal, and aspartame have become, some studies have indicated that they actually cause weight gain (and Stevia has been known to cause the death of certain annoying television characters as well). Now, a controversial new study from the Weizmann Institute of Science in Rehovot, Israel has concluded that artificial sweeteners may actually increase one’s risk of diabetes, as well as negatively affect microbes in the stomach.
The human gut, and the microbes and bacteria living there, are more complicated than one might think. They’re responsible for delivering the nutrients in foods, and may also be linked to thinness and/or obesity; they may also affect our moods and mental states. Suffice it to say, there’s a lot more going on in our guts than simple digestion. Scientists at the Weizmann Institute published the results of an experiment they conducted to test the effects of artificial sweeteners — in this case, aspartame (used in Equal), sucralose (the sweetest of the three, used in Splenda), and saccharin (used in Sweet ‘n Low).
The researchers gave mice water sweetened with one of these three and then monitored their blood and glucose levels. After 11 weeks of drinking the sweetened water, the blood glucose levels of the mice increased dramatically when they had a meal high in glucose, essentially indicating that the mice had become glucose intolerant. Glucose intolerance can be indicative of the early stages of diabetes. When the mice received four weeks’ worth of antibiotics, they didn’t demonstrate glucose intolerance, leading the researchers to conclude that the microbes in the gut were involved.
The mice that ingested saccharin had specific gut microbes that when transferred to regular mice also brought along glucose intolerance. The researchers harvested bacteria from the guts of healthy, undosed mice, then cultured them with saccharin, and then put them into other healthy mice — those mice also became glucose intolerant. The bacteria in the gut may produce molecules that in turn produce more glucose in the body, which causes the high blood glucose levels.
The researchers wanted to see how their results applied to humans, so they gave seven human subjects the highest FDA approved dose of saccharin for six days in a row. Four of the subjects displayed higher blood glucose levels and signs of intolerance, leading the researchers to believe that the sweetener “may have directly contributed to enhancing the exact [diabetes] epidemic that they themselves were intended to fight.”
Of course, a study conducted with only seven human subjects is vulnerable to understandable skepticism, but almost certainly will prompt future bigger studies. The study has already generated some controversy, with people expressing frustration at the study’s conclusive title “Artificial sweeteners induce glucose intolerance by altering the gut microbiota,” and expressing concern at the conflating of the three different sweeteners. Still, the main point is a good one: that artificial sweeteners may not be the solution some hope, certainly if they’re used to excess. But they do inspire some pretty awesome music videos.