Sweeteners do not negatively impact health when in line with ADIs, stresses researcher

25 Feb 2019 --- Non-caloric sweeteners have a negligible effect on the gut microbiome and are not significantly linked to cancer and diabetes risk, as long as their consumption is in line with the ADI (Acceptable Daily Intake) recommended intake. This is according to a University of Granada (UGR) study, published in Advances in Nutrition, which reviewed previous evidence on the effects of sweeteners on gut microbiota through experimental research and clinical trials. The researchers note the need for more research on the effects of sweeteners on the composition of human gut microbiota, however.

“Industry should tightly follow the guidelines provided by international authorities in terms of types of sweeteners that are appropriate for specific foods and their recommended doses,” Professor of Biochemistry and Molecular Biology, Ángel Gil Hernández and lead author of the study, tells NutritionInsight.

Diabetes and cancer risk?
Consumers are increasingly cutting back on sugar in their diets, due to the link between a high intake with an array of health risks such as metabolic syndrome, cancer, Type 2 diabetes and cardiovascular diseases. As a result, sweeteners are rising in popularity since they mimic the sweet taste of sugar, but research is still exploring their link to the aforementioned health risks.

As with any food additive, the Joint Scientific Committee of the Food and Agriculture Organization of the United Nations/World Health Organization FAO/WHO (JECFA) is evaluating and approving the use of sweeteners in foods. Sweeteners are evaluated based on scientific evidence, considering particularly if they have no toxic and carcinogenic effects. Then different authorities such as the US Food and Drug Administration (FDA) and European Food Safety Authority (EFSA) for the EU provide specific guidelines of use and limitations for specific countries Hernández explains.

“Two of the fields the JECFA and other authorities evaluate, are the impact of sweeteners on glycemic index and the potential use by diabetic patients, as well as the safety in view of cancer. Hence, all approved sweeteners can be used by diabetic patients in the appropriated doses,” he adds.

Sweeteners and the microbiome
The review discusses the evidence supporting the effects of both synthetic sweeteners such as acesulfame K, aspartame, cyclamate, saccharin, neotame, advantame and sucralose and natural sweeteners such as thaumatin, steviol glycosides, monellin, neohesperidin dihydrochalcone and glycyrrhizin, as well as low-calorie sweeteners such as polyols or sugar alcohols, on the composition of microbiota in the human gut.

The results of the review showed that the amounts of both natural and artificial sweeteners consumed by humans are usually below the admissible dietary intakes (ADI) established as safe in the EU, says Hernández.

“There is a clear message here. Based on the current evidence, the use of non-nutritive and low-calorie sweeteners is safe as they do not have adverse effects on intestinal microbiota when consumed in amounts lower than those established by international authorities,” Hernández says. “Only a few, such as saccharin, sucralose and steviosides are able to modulate the intestinal microbiota when used in high doses, but the influences on health and disease are unknown. This is one of the main reasons we need further well-designed studies in this area.”

Professor of Biochemistry and Molecular Biology, Ángel Gil Hernández.Dietary habits also have a significant impact on intestinal microbiota and “within this context, the particular food pattern of each population and the relative intake of macronutrients and fiber exert a major role in the establishment of a specific microbiota profile,” he adds. “Minority compounds, such as sweeteners, should have a lower effect.”

“In addition, many sweeteners like those derived from amino acids such as aspartame, neotame and advantame, are fully hydrolyzed at the intestine level and the resulting amino acids are very well absorbed at the small intestine. The amount of those sweeteners reaching the large bowel is negligible. Opposite to this, some other sweeteners are not absorbed and might have some impact in the gut microbiota, especially if they are consumed in high amounts,” Hernández explains.

“Polyols can be absorbed, at least partially, in the small intestine by passive diffusion, but a number of them, such as isomaltose, maltitol, lactitol, and xylitol can reach the large bowel and increase the numbers of bifidobacteria in humans, which would be considered as a potentially beneficial effect,” he notes.

Additionally, another study, recently published in the journal Food and Chemical Toxicology carried out using only in vivo trials found that there is no evidence of low-calorie sweeteners exerting adverse effects on gut microbiota, according to Hernández.

Further research is crucial
There is surprisingly little research on the potential roles of non-nutritive and low-calorie sweeteners on intestinal microbiota, particularly in humans, according to the researchers.

“As the number of studies related to intestinal microbiota and consumption of non-nutritive and low-calorie sweeteners in humans is very limited, there is an actual need to perform well-designed intervention studies,” Hernández notes.

Long-term, double-blind, placebo-controlled, randomized clinical trials with appropriated doses, close to admissible daily intake are needed. This is to evaluate the potential impact of sweeteners on intestinal microbiota and how they could affect major outcomes and risk biomarkers related to chronic diseases, he concludes.

By Kristiana Lalou

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