Chewing Gum

The earliest evidence of humans chewing gum-like substances comes from the convergence of anthropology and dentistry¹ at an archeological site in Sweden, where lumps of birch bark tar with tooth impressions of children and adolescents, dating back 9,000 years, have been found. The ancient Greeks seemed to have chewed on a similar substance, known as mastic, from which the word “mastication” likely derives. Native American Indians and Inuit chewed gum from spruce trees, a custom adopted by the Europeans who settled in New England.²

The U.S. chewing gum market is divided, in part, by product type into sugar-containing chewing gums and sugar-free chewing gums.³ Sugar-containing chewing gums contain monosaccharides (e.g., glucose, fructose, galactose) or disaccharides (e.g., sucrose, maltose, lactose). Sugar-free gums are sweetened with polyols such as xylitol, sorbitol, mannitol or maltitol, which are noncariogenic. They provide a sweet taste but are not a suitable substrate for oral bacteria to use as an energy source.⁴

Although there is some evidence that regular use of sugar-free gum may reduce caries risk,⁴ the gum is not to be used as a substitute for a regular oral hygiene routine consisting of twice daily brushing with a fluoride toothpaste and daily cleaning between teeth.

Only sugar-free chewing gums are considered for the ADA Seal of Acceptance. Excluding sugar-containing gum from ADA Seal consideration is consistent with efforts to align with World Health Organization recommendations which suggest limiting sugar intake to 10% or less of energy intake for optimal oral health.⁵

Chewing gum after a meal can increase salivary flow by stimulating both mechanical and taste receptors in the mouth. The average unstimulated salivary flow rate for healthy people is 0.3-0.4 mL/min.⁶ The physical act of chewing stimulates salivary flow: simply chewing unsweetened, unflavored chewing gum base stimulates the salivary flow rate by 10-12 times that of the unstimulated rate.⁷ Flavors also act as salivary stimulants.⁶ The stimulated salivary flow rate is significantly greater while chewing sweetened and flavored gum as opposed to unsweetened, unflavored chewing gum base.^{7, 8} Increasing saliva volume helps to dilute and neutralize acids produced by the bacteria in plaque on teeth. Over time, these acids can damage tooth enamel, potentially resulting in decay.

There are several mechanisms by which stimulated saliva flow may protect against dental caries. Increased saliva flow carries with it calcium and phosphate ions, which can contribute to remineralization of tooth enamel; the presence of fluoride in the saliva can serve to replace enamel components magnesium and carbonate with the stronger, more caries-resistant fluorapatite crystals.⁹ Saliva can buffer the effects of acids in foods or drinks that could otherwise soften teeth’s enamel surface, and swallowing excess saliva created by stimulation clears acid.⁸ While unstimulated saliva does not have a strong buffering capacity against acid, stimulated saliva has higher concentrations of protein, sodium, calcium, chloride, and bicarbonate increasing its buffering capacity.⁶ Additionally, saliva contributes proteins to dental surfaces, creating an acquired enamel pellicle that protects against dental erosion.^{6, 8}

Sugar-containing Chewing Gum

Monosaccharides and disaccharides may be used in sugar-containing chewing gum. These fermentable carbohydrates can be metabolized by oral bacteria. The bacteria (particularly S. mutans and Lactobacillus spp.) in turn produce dental biofilm and acid, which can lead to enamel demineralization and caries.¹⁰ The potential cariogenicity of sugar-containing gum depends on the physical consistency, oral retention time of the gum, the frequency with which it is chewed, and the sequence of consumption (for instance, chewing sugar-containing gum before eating foods that reduce acid production will be less cariogenic than the reverse).¹⁰

Sugar-free Chewing Gum

As defined by the Food and Drug Administration (FDA) in the Code of Federal Regulations (CFR) a food or food substance such as chewing gum, can be labeled as “sugar-free” if it contains less than 0.5 g of sugars per serving.¹¹ In place of sugar, these gums use high-intensity sweeteners such as aspartame, acesulfame-K, neotame, saccharin, sucralose or stevia.¹² They also may be sweetened with sugar alcohols such as erythritol, isomalt, maltitol, mannitol, sorbitol, or xylitol.¹² These high-intensity sweeteners, with the exception of aspartame, are considered non-nutritive and contain fewer calories than sugar, but the FDA categorizes aspartame, as well as the aforementioned sugar alcohols, to be nutritive sweeteners, since they contain more than 2% of the calories in an equivalent amount of sugar.¹³

Clinical trials have found decreased caries incidence in subjects who chewed sugar-free gum for 20 minutes after meals.^{14, 15} Unlike sugar, these sweeteners are noncariogenic, since they are metabolized slowly or not at all by cariogenic plaque bacteria.¹⁶ A 2021 systematic review and meta-analysis by Nasseripour et al.¹⁷ examined the use of sugar-free gum sweetened with xylitol and reported that the use of sugar-free chewing gum resulted in a statistically significant reduction in the S. mutans load.  The authors reported an effect size of -0.42 (95% CI: -0.60 to -0.25), which is suggestive of its benefit as an adjunct to recommended home oral hygiene.¹⁷

Look for the ADA Seal—your assurance that the product has been objectively evaluated for safety and efficacy by an independent body of scientific experts, the ADA Council on Scientific Affairs.

A company earns the ADA Seal by demonstrating that its sugar-free chewing gum product meets the requirements for safety and efficacy. Efficacy may include one or more specific indications, such as reducing plaque acids, promoting remineralization of tooth enamel, reducing cavities and/or reducing gingivitis. Studies must also show that the gum is safe to oral tissues. The manufacturer must provide the results of laboratory studies and/or clinical studies (e.g., surrogate studies demonstrating increased salivary flow) in humans.

Does the ADA award its Seal to sugar-containing gum?

To date, the only chewing gums with the ADA Seal are sugar-free. They are sweetened by non-cavity-causing sweeteners such as aspartame, sorbitol, xylitol, or mannitol. Chewing sugar-free gum has been shown to increase the flow of saliva, thereby reducing plaque acid, strengthening the teeth and reducing tooth decay.

1. American Dental Association Oral Health Topic: Forensic Dentistry and Anthropology. 2022. "https://www.ada.org/resources/research/science-and-research-institute/oral-health-topics/forensic-dentistry-and-anthropology". Accessed May 11, 2023.
2. Mathews JP. Chicle: The Chewing Gum of the Americas, from the ancient Maya to William Wrigley: The University of Arizona Press; 2009.
3. Mordor Intelligence Chewing Gum Market - Growth, Trends, COVID-19 Impact, and Forecasts 2021-2026.  2021. "https://www.mordorintelligence.com/search?q=chewing%20gum%20market".
4. Deshpande A, Jadad AR. The impact of polyol-containing chewing gums on dental caries: a systematic review of original randomized controlled trials and observational studies. J Am Dent Assoc 2008;139(12):1602-14.
5. World Health Organization and the United Nations Food and Agriculture Organization (WHO/FAO) Diet, nutrition and the prevention of chronic diseases (Report 916). Geneva, Switzerland: World Health Organization 2003. "http://apps.who.int/iris/bitstream/10665/42665/1/WHO_TRS_916.pdf?ua=1". Accessed January 26, 2017.
6. Dawes C, Pedersen AM, Villa A, et al. The functions of human saliva: A review sponsored by the World Workshop on Oral Medicine VI. Arch Oral Biol 2015;60(6):863-74.
7. Dawes C, MacPherson LM. The distribution of saliva and sucrose around the mouth during the use of chewing gum and the implications for the site-specificity of caries and calculus deposition. J Dent Res 1993;72(5):852-7.
8. Buzalaf MA, Hannas AR, Kato MT. Saliva and dental erosion. J Appl Oral Sci 2012;20(5):493-502.
9. Humphrey SP, Williamson RT. A review of saliva: normal composition, flow, and function. J Prosthet Dent 2001;85(2):162-9.
10. Touger-Decker R, van Loveren C. Sugars and dental caries. Am J Clin Nutr 2003;78(4):881S-92S.
11. Code of Federal Regulations Part 101 Food Labeling. 21 CFR § 101.60 CH. 1, p. 131.   2022. "https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-101#101.60". Accessed May 2 2023.
12. International Chewing Gum Association The Science and Technology Behind Chewing Gum Ingredients. "http://www.gumassociation.org/index.cfm/science-technology/ingredients-technology/". Accessed 3/26/2019.
13. U.S. Food and Drug Administration Additional Information about High-Intensity Sweeteners Permitted for Use in Food in the United States. "https://www.fda.gov/food/food-additives-petitions/additional-information-about-high-intensity-sweeteners-permitted-use-food-united-states#nutritive". Accessed August 8, 2021.
14. Mickenautsch S, Leal SC, Yengopal V, Bezerra AC, Cruvinel V. Sugar-free chewing gum and dental caries: a systematic review. J Appl Oral Sci 2007;15(2):83-8.
15. Stookey GK. The effect of saliva on dental caries. J Am Dent Assoc 2008;139 Suppl:11S-17S.
16. Burt BA. The use of sorbitol- and xylitol-sweetened chewing gum in caries control. J Am Dent Assoc 2006;137(2):190-6.
17. Nasseripour M, Newton JT, Warburton F, et al. A systematic review and meta-analysis of the role of sugar-free chewing gum on Streptococcus mutans. BMC Oral Health 2021;21(1):217.
18. Kamimori GH, Karyekar CS, Otterstetter R, et al. The rate of absorption and relative bioavailability of caffeine administered in chewing gum versus capsules to normal healthy volunteers. Int J Pharm 2002;234(1-2):159-67.
19. U.S. Department of Health and Human Services. Smoking Cessation. A Report of the Surgeon General. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2020.
20. Russell M. Physiological and Performance Effects of Caffeine Gum Consumed During a Simulated Half-Time by Professional Academy Rugby Union Players. Journal of Strength and Conditioning Research 2020;34(1):145-51.
21. Sammut R, Trapani J, Deguara J, Ravasi V. The effect of gum chewing on postoperative ileus in open colorectal surgery patients: A review. J Perioper Pract 2021;31(4):132-39.
22. Wallstrom A, Frisman GH. Facilitating early recovery of bowel motility after colorectal surgery: a systematic review. J Clin Nurs 2014;23(1-2):24-44.
23. Nelson G, Bakkum-Gamez J, Kalogera E, et al. Guidelines for perioperative care in gynecologic/oncology: Enhanced Recovery After Surgery (ERAS) Society recommendations-2019 update. Int J Gynecol Cancer 2019;29(4):651-68.
24. Azhar RA, Bochner B, Catto J, et al. Enhanced Recovery after Urological Surgery: A Contemporary Systematic Review of Outcomes, Key Elements, and Research Needs. Eur Urol 2016;70(1):176-87.
25. Mercadante V, Jensen SB, Smith DK, et al. Salivary Gland Hypofunction and/or Xerostomia Induced by Nonsurgical Cancer Therapies: ISOO/MASCC/ASCO Guideline. J Clin Oncol 2021;39(25):2825-43.
26. Yarom N, Hovan A, Bossi P, et al. Systematic review of natural and miscellaneous agents, for the management of oral mucositis in cancer patients and clinical practice guidelines - part 2: honey, herbal compounds, saliva stimulants, probiotics, and miscellaneous agents. Support Care Cancer 2020;28(5):2457-72.

What products have earned the ADA Seal of Acceptance?

Get a Complete List of ADA Accepted Chewing Gum

Additional ADA Resources

• JADA “For the Patient” pages: Shopping Smart: Look for the Seal, Oral Effects of Head and Neck Cancer Treatment, and Is Your Mouth Always Dry?
• ADA MouthHealthy: Chewing Gum