Researchers from the University of Hong Kong and the Ohio State University conducted a systematic review and meta-analysis of clinical trials involving children and adolescents. They found that low-intensity sugar substitutes like xylitol and sorbitol can prevent dental caries by influencing the adhesiveness and growth of bacteria on teeth.
“Results of the current study highlight that xylitol and sorbitol have been extensively researched, with evidence supporting their efficacy as self-applied caries preventive agents. This is attributed to their caries-preventive effects compared to other sugar alcohols or control substances,” said the researchers.
Dental caries or tooth decay is characterised by the localised destruction of tooth structure by acidic by-products resulting from bacterial fermentation of carbohydrates. This is due to consumption of cariogenic foods like noodles, rice, and sweet desserts that contain high amounts of starch and sugars. Thus, controlling carbohydrate and sugar intake is crucial for preventing dental caries.
Sugar substitutes are typically classified into two main categories: low-intensity sweeteners and high-intensity sweeteners. Low-intensity sweeteners, such as xylitol and sorbitol, provide a sweet taste with fewer calories than sugar. High-intensity sweeteners like saccharin, aspartame, and sucralose, are significantly sweeter than sugar and require smaller amounts to achieve the desired level of sweetness. Most sugar substitutes available on the market have undergone rigorous testing and have been deemed safe for consumption by regulatory bodies such as the U.S. Food and Drug Administration (FDA).
Sugar alcohols from fruits and plants have been used in different edible forms for years, and xylitol and sorbitol have been extensively investigated for their relationships with dental caries. However, the effectiveness of these sugar alcohols in different forms and consumption frequencies in preventing dental caries has yielded conflicting results.
Therefore, this study aimed to review the scientific evidence assessing the effectiveness of sugar substitutes in caries prevention in children and adolescents through clinical trials.
The study
From 1 June 2023 to 30 June 2023, the researchers conducted a search in three databases PubMed, Web of Science and Embase without any restrictions on publication year. Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing the clinical effect of sugar substitutes (both high- and low-intensity sweeteners) in preventing caries in permanent teeth among children and adolescents were included. The duration of each study was at least 3 months and the follow-up period was at least 6 months from start to end of each trial.
Fifteen studies that included 11 RCTs and 4 CCTs, with a total of 6,325 participants aged 6–18 years old were included. New dental caries development were measured by increases in DMFS – decayed (D), missing due to caries (M), and filled (F) surfaces (S) – from the start to end of each trial.
Eighty percent of the studies were conducted in children aged 6–12 years and 20% involved adolescents aged 13 years or older. No clinical trial on high-intensity sweeteners such as aspartame and saccharin was found. All investigated sugar substitutes were low-intensity sweeteners, including xylitol, sorbitol, and erythritol.
These studies included regions in China and Kuwait, where participants chewed sorbitol gum and took xylitol candy. The Kuwait study had 135 participants from 10–18 years old, while the China study had 773 children between 6–7 years old.
Xylitol was the most commonly investigated (73.3%), followed by sorbitol (46.7%) and erythritol (13.3%). These sweeteners were administered in various forms such as chewing gum, candy, gummy bears, lozenges, and tablets, with chewing gum being the most commonly investigated (53.3%). Additionally, most (86.7%) of the included studies had a follow-up period of more than two years. Ninety-three percent of them implemented the study trials at school.
Results and implications
In summary, children and adolescents who consumed xylitol and sorbitol products experienced a significantly lower DMFS increment compared to those with placebo or no treatment
“In the meta-analyses, children or adolescents who consumed xylitol or sorbitol products were associated with a lower DMFS increment compared to those who consumed placebo products or did not consume any. Regarding the comparison between xylitol and sorbitol products, children or adolescents who consumed xylitol products were associated with a lower DMFS increment compared to those who consumed sorbitol. Erythritol was found to have a significantly lower DS increment compared to xylitol or sorbitol,” said the researchers.
The researchers observed that their findings align with previous research, which has shown the positive effects of xylitol chewing gum on preventing the development of dental caries. Clinical trials have also documented the effects of edible xylitol products on reducing bacteria in dental plaque and saliva. They said that despite the variations in study design or inclusion criteria, their findings consistently lead to the same conclusion.
Two trials also found that compared to the sealant or fluoride varnish method, xylitol was found to be just as effective in preventing dental caries.
“This review further substantiates that xylitol outperforms sorbitol in caries prevention. This aligns with a previous report indicating that sorbitol lacks the same potent effect as xylitol in influencing the adhesiveness and growth of bacteria, particularly mutans streptococci. Regarding erythritol, two studies included in this review presented conflicting results regarding its effectiveness in preventing caries. Further well-designed clinical studies are imperative to draw a definitive conclusion,” said the researchers.
In contrast to low-intensity sweeteners which have few reports of adverse side effects and are generally regarded as safe for daily consumption, high-intensity sweeteners are viewed as a potential risk factor when used over the long term, potentially resulting in negative health effects and diseases.
Based on the findings, the use of high-intensity sweeteners for caries prevention is not supported due to the absence of clinical evidence. Before high-intensity sweeteners can be recommended for caries prevention, future studies are needed to better understand their impact on caries and overall health.
“The use of xylitol or sorbitol as sugar substitutes is potentially effective in preventing caries in permanent teeth among children and adolescents. However, there is currently no clinical evidence available regarding the role of high-intensity sweeteners in caries prevention,” concluded the researchers.
The findings will offer valuable insights for stakeholders like dental practitioners, policymakers, and parents when selecting appropriate sugar substitutes for children.
Source: Journal of Dentistry
DOI: https://doi.org/10.1016/j.jdent.2024.105069
“Sugar substitutes on caries prevention in permanent teeth among children and adolescents: a systematic review and meta-analysis”
Authors: Bella Weijia Luo, Nicky Linlin Liang et al.
