A new study by the Weizmann Institute of Science in Israel calls into question the alleged safety of artificial sweeteners. In fact, says one researcher, they may even do the very thing users are trying to prevent.
“In our studies we found that artificial sweeteners may drive, or contribute to…an exaggerated elevation in blood glucose levels – the very same condition that we often aim to prevent by consuming them,” said Dr. Eran Elinav of the Immunology Department. He led the study, along with Prof. Eran Segal from the Computer Science and Applied Mathematics Department.
The results of the experiments conducted were published in the journal Nature on Wednesday. Although the extent of the research was not enough for the scientists to make recommendations, they are suggesting further investigation is warranted.
The research team conducted a variety of experiments to test their theory that artificial sweeteners alter the body’s microbiome, or collection of bacteria present in the digestive system. Altering the microbiome can lead to elevated glucose levels which remain high for longer periods after eating. This glucose intolerance is a precursor to diabetes.
In the first experiment, the scientists fed groups of mice different compounds – plain water, sugar water, or artificially sweetened water. After one week, all three groups were given a dose of sugar, and the effects were monitored. The first two groups showed no difference in blood sugar levels, but the mice fed the artificially sweetened water showed a marked glucose intolerance. The same was true whether the artificial sweetener used was saccharin (used in Sweet ‘N Low); sucralose (Splenda), or aspartame (Equal).
Another experiment, involving injecting intestinal bacteria from saccharin-fed mice into healthy mice, demonstrated that the recipient mice developed the same glucose intolerance, and the that the microbiomes of the mice who had consumed the saccharin were indeed different.
To test the effect on humans, the researchers surveyed 381 non-diabetic participants and discovered a correlation between reported sweetener use and glucose intolerance. The sweetener users also had altered intestinal bacteria.
A final experiment saw seven healthy adults who do not normally use artificial sweeteners consume the FDA maximum recommended daily intake for six days. Four of the seven showed signs of glucose intolerance following the experiment. Additionally, the three participants who did not show a change in blood-glucose levels also had different intestinal bacteria than those who did. This seems to suggest probiotics may be useful in treating glucose intolerance.
The results of Elinav and Segal’s research are compelling, but not conclusive. “This research raises caution that artificial sweeteners may not represent the ‘innocent magic bullet’ they were intended to be to help with the obesity and diabetes epidemics, but it does not yet provide sufficient evidence to alter public health and clinical practice,” said Nita Forouhi, program leader at the Medical Research Council’s epidemiology unit at Cambridge University.
Meanwhile, the FDA issued a statement reminding the public that artificial sweeteners “have been thoroughly studied and have a reasonable certainty of no harm to consumers.”
Still, the study provides some ‘food for thought’, so to speak. Even its author has been moved by what he has seen.
“I’ve consumed very large amounts of coffee, and extensively used sweeteners, thinking like many other people that they are at least not harmful to me and perhaps even beneficial,” Elinav said. “Given the surprising results that we got in our study, I made a personal preference to stop using them.
“We don’t think the body of evidence that we present in humans is sufficient to change the current recommendations,” he continued. “But I would hope it would provoke a healthy discussion.”