A recent research reveals that combining artificial sweeteners with carbohydrates affects a person’s response to sweet tastes, which may influence the sensitivity to insulin.
Detect is not just a feeling that helps us to enjoy gourmet delicacies— it plays a very practical function in health-care.
Our capacity to detect unpleasant flavours has helped mankind steer clear of poisonous plants and bad food.
But taste can also support other ways our bodies stay healthy. The sensitivity to sweet taste of a healthy person allows his or her body to release insulin into the blood when that person eats or drinks something sweet.
Insulin is a main hormone which has the primary role of controlling blood sugar. Many metabolic disorders, including diabetes, can develop when insulin sensitivity is compromised.
New research led by researchers at Yale University in New Haven, CT and other academic institutions has now come to a shocking conclusion.
The researchers suggest in a study paper published in Cell Metabolism that a mixture of artificial sweeteners and carbohydrates in healthy adults tends to result in lower insulin sensitivity.
“When we set out to do this research, the problem that drove us was whether or not repeated ingestion of an artificial sweetener would lead to a deterioration of the sweet taste’s predictive ability,” explains senior author Prof. Dana Low.
“This would be important because sweet-taste perception may lose the ability to control metabolic responses that will prepare the body to normally metabolize glucose or carbohydrates,” she adds.
The squad, however, was surprised to find an entirely different find.
Sucralose and carbs: A bad mix?
The researchers recruited 45 healthy adults aged 20–45 for their study, who said they usually did not drink low calorie sweeteners.
The researchers did not ask participants to make some adjustments to their normal diets in the laboratory other than consuming seven fruit-flavored beverages. The drinks contained either artificial sucralose sweetener, or normal table sugar.
Several participants— who were expected to form the control group— had sucralose-sweetened drinks that also included the carbohydrate maltodextrin.
The researchers used maltodextrin to control the number of calories in the sugar without sweetening the beverage.
This experiment lasted for 2 weeks and the investigators performed additional tests on the participants before, during, and after the study — including functional MRI scans.
The tests allowed scientists to determine any changes in brain activity of the participants in response to different tastes— including sweet, sour, and salty— as well as assess their perception of taste and sensitivity to insulin.
But the investigators find unexpected findings when they analyzed the data they had collected up until now. This was the intended control group who exhibited altered brain responses to sweet tastes, as well as altered insulin sensitivity and glucose (sugar) metabolism — the participants who had consumed sucralose and maltodextrine together.
The researchers asked another group of participants to drink beverages containing either sucralose alone or maltodextrin alone over a further 7-day period to check the validity of those findings.
The team found that neither the sweetener alone nor the carbohydrate alone seemed to interfere with the response to the sweet taste or the sensitivity to insulin.
Best to swap diet drinks for water
What happened, then? Why has the sweetener-carb combination influenced the ability of participants to detect sweet tastes, as well as their response to insulin?
The researchers can not say for sure yet, but they do have some working hypotheses.
“Perhaps the result was that the gut produced misleading signals about the number of calories present to send to the brain,” Prof. Small suggests.
“The gut would be responsive to sucralose which maltodextrin, and would signal the availability of twice to many calories as are actually present. Such incorrect signals may have detrimental results over time by altering the way the brain and body respond to the sweet taste,” she adds.
The researchers also refer in their study paper to earlier rodent studies, in which the researchers fed the animal pure yogurt they had applied artificial sweeteners to.
This intervention, say the investigators, led to similar effects as the ones they found in the current study, which leads them to conclude that the combination of yogurt sweeteners and carbs may have been responsible.
“Previous rat studies have shown that improvements in the ability to use the sweet taste to control behavior over time can contribute to metabolic impairment and weight gain. We believe this is because of the energy intake of artificial sweeteners,” says Prof. Low.
“Our findings suggest that it’s OK to have a Diet Coke once in a while, but you shouldn’t drink it with something that has a lot of carbs. If you’re eating French fries, you’re better off drinking a regular Coke or — better yet — water. This has changed the way that I eat and what I feed my son. I’ve told all my friends and my family about this interaction.”
– Prof. Dana Small
The investigators are planning to try to find out if other artificial sweeteners, as well as sweeteners of natural origin, such as stevia, result in the same effects as sucralose when combined with carbohydrates.
Reflecting on the findings of the study, Sarah Berry, Ph.D. — a senior lecturer at King’s College London in the UK who was not involved in this research — states that the study had a good approach, and its result would lead to further inquiries into sweeteners and their potential health effects.
“From a public health perspective, this work is important in that we are typically consuming sweeteners alongside foods containing carbohydrates,” notes Berry.
“For instance,” she goes on to point out, “sweeteners are found together with other carbohydrates in many processed low calorie and low sugar foods.”
Nevertheless, she adds: “A word of caution; such findings can not be generalized to all sweeteners because the main types of various sweeteners typically introduced into our foods and drinks (including sucralose, aspartame, saccharin, and Ace-K) are metabolized differently and will therefore have different health effects.”
You can read her full comment here.