Share on Pinterest Sugar alternatives may not be as harmless as you think. Marie LaFauci/Getty Images
- Researchers conducted a randomized controlled trial to investigate the effects of artificial sweeteners such as aspartame, saccharin, stevia and sucralose on human metabolism and the gut microbiome.
- They found that these non-nutritive sweeteners can induce individual and specific changes in glycemic response by modifying the gut microbiome.
- This discovery challenges the popular notion that sugar substitutes have no effect on the human body and highlights the need for further clinical studies.
After eating foods containing carbohydrates, blood glucose (blood sugar) levels rise as we digest the food. This increase in blood glucose levels after meals is known as the glycemic response.
Non-nutritive sweeteners (NNS), such as aspartame, saccharin, stevia, and sucralose, contain minimal or no carbohydrates, and therefore scientists assumed they did not trigger a glycemic response. This belief that NNS are biologically inert, along with their sweetness, has made them very popular sugar substitutes, especially for the management of diabetes and weight gain.
In a study published in 2014, Dr. Eran Elinav, an immunologist and microbiome researcher at the Weizmann Institute of Science in Israel and the Division of Microbiome and Cancer, DKFZ, Heidelberg, Germany, along with his team challenge the idea that NNS are biologically inert. . The study established that non-caloric artificial sweeteners induce glucose intolerance in mice by altering their gut microbiota.
Now, a new study published by Dr. Elinav and his team in the journal Cell show that NNSs have a similar effect in humans.
“We need to raise awareness that non-nutritive sweeteners are not as inert to the human body as we originally thought.” – Dr. They were Elinav
“This is a very strong and rigorous study, and the results are important and timely,” said Dr. Michael Goran, professor of pediatrics at the Keck School of Medicine at the University of Southern California and director of the Diabetes Program and obesity at the Saban Research Institute. at Children’s Hospital Los Angeles, which was not involved in this study, told Medical News Today. Dr. Goran is also the author of Sugarproof.
“Non-nutritive sweeteners are rapidly proliferating in the food supply and in all demographic groups, including children and pregnant women, but their full and long-term impact on human health has not been widely studied,” he said. to say.
The researchers recruited into the study only healthy volunteers who did not consume any NNS in their daily diet. A total of 120 people passed the strict screening test and the researchers randomly assigned them to one of six supplementation groups: aspartame, saccharin, stevia, sucralose, glucose (to control for potential interference from glucose in standard formulations of NNS) and no supplement (the second control group).
All sweeteners were given as commercially available sachets, which contained a glucose mixture and in doses below the acceptable daily intake recommended by the FDA.
To investigate the effect of NNSs on glycemic response, participants wore a continuous glucose monitor throughout the clinical trial and completed glucose tolerance tests on predetermined days. The glucose tolerance test measures the body’s ability to absorb and use glucose (sugar).
The researchers found that the saccharin and sucralose groups had a “significantly elevated” glycemic response during NNS exposure. No significant effect on glucose tolerance was observed in the aspartame, stevia, glucose, and no-supplement groups.
These findings suggest that short-term consumption of saccharin and sucralose at doses below acceptable daily intake may affect glycemic responses in healthy individuals.
Based on findings from animal model studies, researchers hypothesized that NNSs may affect human metabolism by altering the gut microbiome. To test their hypothesis, the researchers analyzed stool microbiome samples from the participants before and after consuming NNS.
They found that all four NNSs tested altered gut bacteria and the molecules they secrete. Similarly, all four NNSs “clearly affected” the oral microbiome.
These changes in the microbiome did not occur in the control groups. These findings suggest that NNSs are not inert to the human microbiome.
“[The study is] a first step to confirm what many have long suspected; that artificial sweeteners have a measurable impact on metabolism and health. The results propose a valid mechanism of action for the downstream effects on glycemic control of sweeteners, through interaction with the gut microbiome.
To determine whether changes in the microbiome were indeed the cause of the altered glycemic responses, the researchers transplanted gut bacteria from study participants into germ-free mice—mice that had been raised in completely sterile conditions and had no microbiome of their own .
Collectively, these mice showed glycemic responses that mirrored those of their human microbiome donors.
These results suggest that human microbiome responses to NNSs are highly personalized and may lead to glycemic disturbances in some but not all consumers, depending on their microbiomes and the NNS they consume.
The idea that the human gut microbiome can respond to certain food additives and trigger metabolic changes is not new. Previous studies have suggested that dietary emulsifiers, food preservatives, and dyes promote metabolic changes by altering the microbiome.
Most recently, researchers found that a new low-calorie sweetener promotes the growth of beneficial gut bacteria, which affects overall health.
When asked about the limitations of the study, Dr. Elinav noted that the clinical trial included only healthy, non-overweight, normoglycemic individuals, and participants were administered only one formulation of NNS.
“Our results call for more randomized, non-industry-sponsored intervention studies in at-risk populations, such as prediabetics and diabetes. Other NNS[s]formulations and doses need to be explored further,” said Dr Elinav.
“Furthermore, the impacts of NNS should be compared in future controlled trials between high-carbohydrate consumers and [carbohydrate]-restrictive diets due to their possible differential effects on human metabolic physiology. A longer exposure period than that used in our study may be necessary to fully assess the potential health ramifications mediated by the altered microbiome after consumption of different NNS.[s],” added.
Dr. Goran, who was not involved in the study, suggested that other sweeteners, including monk fruit sweetener and allulose, are becoming more popular and should also be examined.
“We also need studies in children because their microbiome is still developing and so the impact of these compounds could be different and affect long-term outcomes,” he said.
“In addition, this paper has very detailed information on microbiome outcomes and glycemic responses, but other outcomes of interest include general effects on appetite regulation as well as cognitive effects, as there is evidence to suggest adverse effects in these two results,” he added.
Professor Spector, who was also not involved in the study, pointed out that the additives or dyes in these sweeteners may also be behind these effects.
“As the authors have stated in this paper, it is likely that emulsifiers, additives and artificial colors affect the human microbiome and thus the metabolic response, but whether it is a glycemic response or something else is still unclear” , he told MNT.
Dr. Goran suggests avoiding all sweeteners “until we have stronger evidence that they’re safe.”
“None of [the non-nutritive sweeteners] will solve [the] craving for sweet taste and there are studies that suggest that the regular consumption of sweeteners increases the daily consumption of calories and sugar in general. – Dr. Michael Goran
Prof. Spector echoed similar thoughts:
“The results of the study imply that the response is variable between individuals, but all sweeteners seem to have some kind of impact, so none of them seem better than the others and I would personally avoid them.”
Although the results of this study raise concerns about the effects of NNS on human health, Dr. Elinav cautioned that “sugar consumption is still a very bad health risk and well-proven for obesity , diabetes and its health implications, and our results do not support or promote the consumption of sugar in any shape or form.”
“[We] We strongly believe that sugar consumption should be minimized and avoided as much as possible,” he added.