No-calorie sweetener may alter metabolism

WASHINGTON U.-ST. LOUIS (US) — Although sucralose, a popular artificial sweetener, has no calories, it can modify how the body handles sugar.

In a small study, researchers analyzed the sweetener sucralose (Splenda) in 17 severely obese people who do not have diabetes and don’t use artificial sweeteners regularly.

“Our results indicate that this artificial sweetener is not inert—it does have an effect,” says first author M. Yanina Pepino, research assistant professor of medicine at Washington University School of Medicine in St. Louis. “And we need to do more studies to determine whether this observation means long-term use could be harmful.”

“Although we found that sucralose affects the glucose and insulin response to glucose ingestion, we don’t know the mechanism responsible,” says M. Yanina Pepino. “We have shown that sucralose is having an effect. In obese people without diabetes, we have shown sucralose is more than just something sweet that you put into your mouth with no other consequences.” (Credit: awwstin/Flickr)

Pepino’s team studied people with an average body mass index (BMI) of just over 42; a person is considered obese when BMI reaches 30. They  gave subjects either water or sucralose to drink before they consumed a glucose challenge test. The glucose dosage is very similar to what a person might receive as part of a glucose-tolerance test.

The researchers wanted to learn whether the combination of sucralose and glucose would affect insulin and blood sugar levels.

“We wanted to study this population because these sweeteners frequently are recommended to them as a way to make their diets healthier by limiting calorie intake,” Pepino says. The research is available online in the journal Diabetes Care.

Every participant was tested twice. Those who drank water followed by glucose in one visit drank sucralose followed by glucose in the next. In this way, each subject served as his or her own control group.

Metobolic reaction

“When study participants drank sucralose, their blood sugar peaked at a higher level than when they drank only water before consuming glucose,” Pepino explained. “Insulin levels also rose about 20 percent higher. So the artificial sweetener was related to an enhanced blood insulin and glucose response.”

The elevated insulin response could be a good thing, she pointed out, because it shows the person is able to make enough insulin to deal with spiking glucose levels. But it also might be bad because when people routinely secrete more insulin, they can become resistant to its effects, a path that leads to type 2 diabetes.

It has been thought that artificial sweeteners, such as sucralose, don’t have an effect on metabolism. They are used in such small quantities that they don’t increase calorie intake. Rather, the sweeteners react with receptors on the tongue to give people the sensation of tasting something sweet without the calories associated with natural sweeteners, such as table sugar.

But recent findings in animal studies suggest that some sweeteners may be doing more than just making foods and drinks taste sweeter.

One finding indicates that the gastrointestinal tract and the pancreas can detect sweet foods and drinks with receptors that are virtually identical to those in the mouth. That causes an increased release of hormones, such as insulin. Some animal studies also have found that when artificial sweeteners activate receptors in the gut, the absorption of glucose also increases.

Pepino, who is part of the university’s Center for Human Nutrition, says those studies could help explain how sweeteners may affect metabolism, even at very low doses. But most human studies involving artificial sweeteners haven’t found comparable changes.

Sucralose and obesity mystery

“Most of the studies of artificial sweeteners have been conducted in healthy, lean individuals,” Pepino says. “In many of these studies, the artificial sweetener is given by itself. But in real life, people rarely consume a sweetener by itself. They use it in their coffee or on breakfast cereal or when they want to sweeten some other food they are eating or drinking.”

Just how sucralose influences glucose and insulin levels in people who are obese is still somewhat of a mystery.

“Although we found that sucralose affects the glucose and insulin response to glucose ingestion, we don’t know the mechanism responsible,” says Pepino. “We have shown that sucralose is having an effect. In obese people without diabetes, we have shown sucralose is more than just something sweet that you put into your mouth with no other consequences.”

She says further studies are needed to learn more about the mechanism through which sucralose may influence glucose and insulin levels, as well as whether those changes are harmful. A 20 percent increase in insulin may or may not be clinically significant, she added.

“What these all mean for daily life scenarios is still unknown, but our findings are stressing the need for more studies,” she says. “Whether these acute effects of sucralose will influence how our bodies handle sugar in the long term is something we need to know.”

The National Center for Advancing Translational Sciences Clinical and Translational Sciences Award and the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health funded the study. Tate & Lyle, manufactures of Splenda, provided the sucralose.

Source: Washington University in St. Louis

chat8 Comments

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  1. Emma

    Is’nt it better to consume sugar moderately than to take in artificial sweeteners that maybe will affect our health on the long run. What about our ancestors who , l bet, they did’nt have such grave health problems but ate sugar and fat and were living to an advanced age. Are we doing the right thing in eating oil instead of fat, sweeteners instead of sugar, minimal amounts of carbohydrates, chemicals in everything, and treated vegetables and fruits?

  2. Jeff

    Emma – Our ancestors were usually dead by 30, so I’m not sure we should hold them up as shining examples of anything.

  3. Rob Hooft

    Yup. Our ancestors were not only dead by 30, they were also miserably hungry practically all the time before…..

  4. Katharine Nair

    As purchased, each Splenda packet contains 1 gram of dextrose (sugar) as a bulking agent. Was this test conducted with Splenda or a pure form of sucralose? It would not be surprising that Splenda affects glucose and insulin levels.

  5. John

    Our ancestors being dead by 30 years of age is not simply because of diet. Advances in medical sciences have contributed to our longer lifespan. Not to mention the culling of predators that would have easily taken out an elderly person. There are people in this world who do not consume the over processed western diet and still live over 30 years of age.

  6. Zizzle

    It’s not surprising at all that an analogue of sucrose – sucralose – has effects on all the same systems that sucrose itself does. This is a massive under-performance by the company which developed sucralose and neglected to see that, despite being able to be metabolized like sugars, other body mechanisms which also respond to sugar will also respond in some way to analogues. This same methodology is used to develop new drugs (modify a natural substance synthetically, test it, and patent it). By the way, dextrose IS glucose (d-glucose, or dextro-glucose, the natural enantiomer).

    Moreover, what all of this illustrates is that we’ve become too good at pleasing ourselves. We evolved under continuous scarcity, and so our bodily mechanisms still behave this way in large part. Being conscious of this is the first step to becoming healthier. With increasingly dopamine-charged lives (social networking on a smart phone is 6 times as addictive as tobacco smoking) that include ultra-realistic video games and fantasy/sci-fi imagery in movies and TV, combined with foods processed specifically to taste good and be cheap to mass produce, we’re screwing ourselves to the floor. The only real difference between a crack addict and a facebook addict are the rotten teeth and constant itches. If the harms were easier to perceive, there would be PSAs about “just say NO to reality TV”. But alas, in an economic system based on people getting what they want with no focus on the concept of “need”, we’re doomed to get exactly – on only – what we want.

    It must be noted that a study has been done in which an electrode was implanted into a rat’s pleasure center in the brain, and a button activating a little shock in the electrode was placed in the rat’s cage. The rats in the study would basically push the button until they died without eating and barely drinking water. As we march forward with more directly entertaining technology and culture, we march toward that metaphoric electrode in our pleasure centers with the button in hand.

    Something to consider.

  7. Mark

    Emma – our ancestors, at least those before the 20th century, didn’t eat large amounts of refined sugars, if they ate any at all. And the amount they did eat was controlled by circumstances like availability and cost.

    With regard to oil, it’s a very ancient food. People have been cooking with it and eating it for several thousand years at least.

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