The Impact of Sugars on the Global Dental Disease Burden

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The Impact of Sugars on the Global Dental Disease Burden

Sugars are known to impact systemic and oral health, and there is now intense interest in controlling sugar consumption. Overconsumption of sugars is linked to weight gain,1Te Morenga L, Mallard S, Mann J. Dietary sugars and body weight: systematic review and meta-analyses of randomised controlled trials and cohort studies. Br Med J 2013;346:e7492. and the negative impact on health of being overweight or obese is well documented.2World Health Organization. Guideline. Sugars intake for adults and children. Geneva: World Health Organization; 2015.,3Moynihan P. Sugars and dental caries: Evidence for setting a recommended threshold for intake1–3. Adv Nutr 2016;7:149-56. Adverse health effects include an increased prevalence of cardiovascular disease, diabetes mellitus, and certain malignancies (breast, colon and pancreatic).2World Health Organization. Guideline. Sugars intake for adults and children. Geneva: World Health Organization; 2015.,3Moynihan P. Sugars and dental caries: Evidence for setting a recommended threshold for intake1–3. Adv Nutr 2016;7:149-56.,4Mann J. The science behind the sweetness in our diets. Bull World Health Organ 2014;92:780-1. Available here.

While controversial, some studies also suggest that free sugars have a direct health impact on cardiovascular disease and type 2 diabetes.5Stanhope KL. Sugar consumption, metabolic disease and obesity: The state of the controversy. Crit Rev Clin Lab Sci 2016;53(1):52-67. In addition, sugars and starches are fermentable carbohydrates, which are an essential component in the development of dental caries.6Pitts NB, Zero DT, Marsh PD, Ekstrand K, Weintraub JA, Ramos-Gomez F, Tagami J, Twetman S, Tsakos G, Ismail A. Dental caries. Nat Rev Dis Primers 2017;25(3):17030.

Defining sugars

Sugars include those occurring naturally in grains, whole fruits and vegetables (intrinsic sugars), as well as ‘free sugars.’ The World Health Organization (WHO) defines ‘free sugars’ as monosaccharides (e.g., fructose, glucose) and disaccharides (e.g., sucrose) added to foods and drinks during processing, cooking or consumption. Sucrose is consumed globally more than any other free sugar.4Mann J. The science behind the sweetness in our diets. Bull World Health Organ 2014;92:780-1. Available here. Naturally occurring sugars in milk, grains, whole fruits and vegetables are of much less significance for the development of dental caries.3Moynihan P. Sugars and dental caries: Evidence for setting a recommended threshold for intake1–3. Adv Nutr 2016;7:149-56.

Sucrose is consumed globally more than any other free sugar.

A significant proportion of fermentable carbohydrates in the modern diet consists of free sugars, and ingestion results in a more rapid and greater drop in the pH in dental biofilm than with starches.7Bibby BG, Krobicka A. An in vitro method for making repeated pH measurements on human dental plaque. J Dent Res 1984;63:906-9. ‘Added sugars’ is largely synonymous with free sugars, and is a term frequently used in some countries, including the United States (Table 1).4Mann J. The science behind the sweetness in our diets. Bull World Health Organ 2014;92:780-1. Available here Other carbohydrates include oligosaccharides (maltodextrins) and polyols, e.g., xylitol and erythrotol.8Touger-Decker R, van Loveren C. Sugars and dental caries. Am J Clin Nutr 2003;78(suppl):881S–92S. These are noncariogenic.

Table 1. Classification for carbohydrates and sugars 3Moynihan P. Sugars and dental caries: Evidence for setting a recommended threshold for intake1–3. Adv Nutr 2016;7:149-56.,8Touger-Decker R, van Loveren C. Sugars and dental caries. Am J Clin Nutr 2003;78(suppl):881S–92S.
Fermentable carbohydrates
Monosaccharides Fructose, high-fructose corn syrup, glucose, galactose, dextrose
Disaccharides Sucrose, lactose, maltose
Polysaccharides Starches
Non-fermentable carbohydrates
Polyols Xylitol, sorbitol, mannitol, xylitol, erythritol, lactitol, isomalt, maltitol, hydrogenated starch, hydrolysates
Oligosaccharides Maltodextrins
Intrinsic sugars Occur naturally in grains, whole fruits and vegetables
Free sugars Mono- and disaccharides added to foods and drinks during processing, cooking or consumption.

Sugar-related oral disease

A recent analysis of global data sets from 168 countries was conducted to determine the global burden of sugar-related oral disease and the related economic burden for developed countries (n=31).9Meier T, Deumelandt P, Christen O, Stangl GI, Riedel K, Langer M. Global burden of sugar-related dental diseases in 168 countries and corresponding health care costs. J Dent Res 2017;96:845-54. The global oral disease burden was calculated as the sum of disability-adjusted life years (DALYs). These represent a lost year of health and are summed to determine the impact of a disease for a given area. More than a quarter of the global oral disease burden was associated with free sugar intake, with 2.7 million DALYs related to dental caries. Seventy-six percent of the total oral disease burden was borne by countries that are not members of the Organization for Economic Cooperation and Development. The economic burden was US $172 billion in direct and indirect costs, with 88% borne by OECD countries. Costs for the United States, Germany, France, Japan and Italy were US$57.3 billion, $23.1 billion, $8.8 billion USD), $8.6 billion and $8.5 billion, respectively.9Meier T, Deumelandt P, Christen O, Stangl GI, Riedel K, Langer M. Global burden of sugar-related dental diseases in 168 countries and corresponding health care costs. J Dent Res 2017;96:845-54. (Figure 1) These findings emphasize the importance of sugar intake for dental caries.10Keller MK, Kressirer CA, Belstrom D, Twetman S, Tanner ACR. Oral microbial profiles of individuals with different levels of sugar intake. J Oral Microbiol 2017;9:1355207.,11Giacaman RA. Sugars and beyond. The role of sugars and the other nutrients and their potential impact on caries. Oral Dis 2017.

More than a quarter of the global oral disease burden is associated with intake of free sugars.

Figure 1. Sugar-related health costs for select OECD countries (US$ in billions)

 

Consumption of free sugar is believed to create an imbalance in the complex oral biofilm, with overgrowth of cariogenic bacteria and changes in the diversity and proportions of microorganisms, favoring disease. Specific pathogens may play a key role in this shift, e.g., Streptococcus mutans creates a lower pH as a result of metabolic acid production.12Mira A, Simon-Soro A, Curtis MA. Role of microbial communities in the pathogenesis of periodontal diseases and caries. J Clin Periodontol 2017; 44(Suppl. 18):S23–S38.
This lower pH selects for greater proportions of acidogenic and aciduric bacteria which thrive/tolerate acidic environments.13Sanz M, Beighton D, Curtis MA, Cury JA, Dige I, Dommisch H, Ellwood R, Giacaman RA, Herrera D, Herzberg MC, Könönen E, Marsh PD, Meyle J, Mira A, Molina A, Mombelli A, Quirynen M, Reynolds EC, Shapira L, Zaura E. Role of microbial biofilms in the maintenance of oral health and in the development of dental caries and periodontal diseases. Consensus report of group 1 of the Joint EFP/ORCA workshop on the boundaries between caries and periodontal disease. J Clin Periodontol 2017;44(Suppl 18):S5-S11. Sugars also provide microorganisms with fuel to produce the extracellular polysaccharides integral to dental biofilm development.14Bowen WH, Burne RA, Wu H, Koo H. Oral biofilms: Pathogens, matrix, and polymicrobial interactions in microenvironments. Trends Microbiol 2017 Oct 30.,15Cai J-N, Jung J-E, Dang M-H, Kim M-A, Yi H-K, Jeon J-G. Functional relationship between sucrose and a cariogenic biofilm formation. PLoS ONE 2016;11(6):e0157184. Further, sucrose reduces the concentrations of fluoride, calcium and phosphorus in dental biofilm, diminishing their role as protective factors.15Cai J-N, Jung J-E, Dang M-H, Kim M-A, Yi H-K, Jeon J-G. Functional relationship between sucrose and a cariogenic biofilm formation. PLoS ONE 2016;11(6):e0157184.

The dental caries burden

Caries experience from age 6 through adolescence is an estimated 70% worldwide,16Beaglehole R, Benzian H, Crail J, Mackay J. The oral health atlas: Mapping a neglected global health issue. 1st Ed. FDI World Dental Education & Myriad Editions, 2009. while across all age groups untreated dental caries in the permanent dentition has a prevalence of 35% and is the most prevalent disease globally.17Marcenes W, Kassebaum NJ, Bernabé E, Flaxman A, Naghavi M, Lopez A, Murray CJL. Global burden of oral conditions in 1990-2010. A systematic analysis. J Dent Res 2013;92(7):592-7. Untreated dental caries is responsible for acute and chronic pain, and can progress to pulpitis, cellulitis, and in extreme cases brain abscesses and death.18Brook I. Brain abscess in children: microbiology and management. J Child Neurol 1995;10(4):283-8. Pain reduces quality of life for the person and family, and scholastic achievement. In a Sri Lankan survey of almost 600 children 8 years-of-age, oral pain prevalences of 49% were reported by children and 53% by parents on their behalf, mostly related to dental caries.19Ratnayake N, Ekanayake L. Prevalence and impact of oral pain in 8-year-old children in Sri Lanka. Int J Paediatr Dent 2005;15(2):105-12. Based on a subset of 12- and 15-year-olds included in a national oral health survey in Thailand, 5.1% and 4.4%, respectively, missed school due to toothache associated with dental caries.20Krisdapong S, Prasertsom P, Rattanarangsima K, Sheiham A. School absence due to toothache associated with sociodemographic factors, dental caries status, and oral health-related quality of life in 12- and 15-year-old Thai children. J Pub Health Dent 2013;73(4):321-8. Children with severe caries also present with poor growth and lower weight gain.21Malek Mohammadi T, Wright CM, Kay EJ. Childhood growth and dental caries. Community Dent Health 2009;26(1):38-42. Further, untreated dental caries creates a burden for healthcare systems, resulting in emergency visits to medical and emergency facilities.22Casamassimo PS, Thikkurissy S, Edelstein BL, Maiorini E. Beyond the dmft: the human and economic cost of early childhood caries. J Am Dent Assoc 2009;140(6):650-7.

Untreated dental caries is responsible for acute and chronic pain, and can progress to pulpitis, cellulitis, and in extreme cases brain abscesses and death.

Current recommendations on consumption of free sugars

The WHO recently published updated guidelines and recommends limiting free sugars to ˂10% of daily total energy (TE) consumed. A more conservative limit of ˂5% is conditionally recommended.2World Health Organization. Guideline. Sugars intake for adults and children. Geneva: World Health Organization; 2015.,4Mann J. The science behind the sweetness in our diets. Bull World Health Organ 2014;92:780-1. Available here A review of 5 cohort studies found consistent reductions in childhood caries when free sugars were ˂10% of daily TE.23Moynihan PJ, Kelly SAM. Effect on caries of restricting sugars intake: Systematic review to inform WHO guidelines. J Dent Res 2014;93(1):8-18. Based on a systemic review of 55 cohort, interventional and population-based studies, limiting free sugars intake to ˂5% was supported.23Moynihan PJ, Kelly SAM. Effect on caries of restricting sugars intake: Systematic review to inform WHO guidelines. J Dent Res 2014;93(1):8-18. In a fourth review, it was concluded that sugars should be limited to 2% to 3% of total TE and that more than 3 years of consumption at that level could still result in development of dental caries. Further, a dose-response was observed for adults.24Sheiham A, James WP. A new understanding of the relationship between sugars, dental caries and fluoride use: implications for limits on sugars consumption. Public Health Nutr 2014;17(10):2176-84

It is recommended that free sugars be limited to <10% of daily total energy consumed, and more conservatively to <5% of daily total energy.

Strategies to reduce consumption of sugars in the population

Proposed strategies to decrease global consumption of free sugars including sugar-sweetened beverages (SSBs), and to improve health, include packaging changes, labeling and reformulation of foods and beverages to lower or exclude free sugars. Changes have recently been made to labeling in the US, with requirements that ‘added sugars’ be explicitly noted under sugars.25Tierney M, Gallagher AM, Giotis ES, Pentieva K. An online survey on consumer knowledge and understanding of added sugars. Nutrients 2017;9:37. Results from an online survey underscore the need for simpler, more explicit labeling of foods and drinks. Of more than 400 participants, only 4% could properly classify at least 10 of 13 ingredients.25Tierney M, Gallagher AM, Giotis ES, Pentieva K. An online survey on consumer knowledge and understanding of added sugars. Nutrients 2017;9:37. The use of front-of-pack labelling has been proposed.44. Mann J. The science behind the sweetness in our diets. Bull World Health Organ 2014;92:780-1. Available here.,25Tierney M, Gallagher AM, Giotis ES, Pentieva K. An online survey on consumer knowledge and understanding of added sugars. Nutrients 2017;9:37.
Experimentally, plain packaging and warning labels reduced intent to purchase SSBs by adolescents and young adults (p˂0.001).26Bollard T, Maubach N, Walker N, Mhurchu CN. Effects of plain packaging, warning labels, and taxes on young people’s predicted sugar-sweetened beverage preferences: an experimental study. Int J Behav Nutr Phys Activity 2016;13:95.
Other strategies include the imposition of targeted taxes on products containing free sugars, for which results are mixed. In Berkeley, California, a penny per ounce tax on SBBs did not yield a significant reduction in SSBs consumption.27Silver LD, Ng SW, Ryan-Ibarra S, Taillie LS, Induni M, Miles DR, Poti JM, Popkin BM. Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study. PLoS Med 2017;14(4):e1002283. Similarly, respondents to an online survey tool indicated no change in purchasing intent based on a theoretical 20% tax.25Tierney M, Gallagher AM, Giotis ES, Pentieva K. An online survey on consumer knowledge and understanding of added sugars. Nutrients 2017;9:37. Conversely, in a Mexican study a 10% tax resulted in a 6% decline in consumption.26Bollard T, Maubach N, Walker N, Mhurchu CN. Effects of plain packaging, warning labels, and taxes on young people’s predicted sugar-sweetened beverage preferences: an experimental study. Int J Behav Nutr Phys Activity 2016;13:95.
Table 2. Methods for reducing intake of free sugars
Regulatory initiatives
Explicit, easy-to-understand packaging and labeling
Reformulation of foods, drinks and snacks
Warning labels
Targeted taxes on SSBs, other products with free sugars
Initiatives by dental professionals
Nutritional evaluation for caries-active patients
Provide patients with advice on a healthy diet, risks of consuming free sugars, eliminating/reducing free sugars, sugar-free alternatives
Advice on infant formula
Collaboration with other healthcare professionals

The Role of Dental Professionals

Considering that fermentable carbohydrates, in particular free sugars, are a key factor in the development of dental caries, limiting their intake and frequency of consumption is a practical risk reduction strategy. It is recommended that dental professionals perform a nutritional evaluation if active caries is present, and provide advice on a healthy diet and eliminating or reducing the amount, and frequency, of free sugar intake, including SSBs.3Moynihan P. Sugars and dental caries: Evidence for setting a recommended threshold for intake1–3. Adv Nutr 2016;7:149-56.,28Chapple IL, Bouchard P, Cagetti MG, Campus G, Carra MC, Cocco F, Nibali L, Hujoel P, Laine ML, Lingstrom P, Manton DJ, Montero E, Pitts N, Rangé H, Schlueter N, Teughels W, Twetman S, Van Loveren C, Van der Weijden F, Vieira AR, Schulte AG. Interaction of lifestyle, behaviour or systemic diseases with dental caries and periodontal diseases: consensus report of group 2 of the joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases. J Clin Periodontol 2017;44 Suppl 18:S39-S51.,29Moynihan P, Makino Y, Petersen PE, Ogawa H. Implications of WHO Guideline on Sugars for dental health professionals. Community Dent Oral Epidemiol 2017 Nov 23. Patients should also be encouraged to replace free sugar foods, drinks and snacks with sugar-free alternatives,29Moynihan P, Makino Y, Petersen PE, Ogawa H. Implications of WHO Guideline on Sugars for dental health professionals. Community Dent Oral Epidemiol 2017 Nov 23. and to avoid consumption of free sugars within an hour of bedtime.30Goodwin M, Patel DK, Vyas A, Khan AJ, McGrady MG, Boothman N, Pretty IA. Sugar before bed: a simple dietary risk factor for caries experience. Community Dent Health 2017;34(1):8-13. In addition, infant formula containing only lactose has been found to be less cariogenic than those containing non-milk extrinsic sugars.31Tan SF, Tong HJ, Lin XY, Mok B, Hong CH. The cariogenicity of commercial infant formulas: a systematic review. Eur Arch Paediatr Dent 2016;17(3):145-56. Therefore, advice to parents regarding infant formula is also important. The WHO recommends that training in nutrition be included in the dental curriculum globally, with defined content.33. Moynihan P. Sugars and dental caries: Evidence for setting a recommended threshold for intake1–3. Adv Nutr 2016;7:149-56. Dental professionals can also collaborate with other healthcare professionals by cross-referral as well as by promoting public health policies and interventions.

Dental professionals should provide advice on a healthy diet and eliminating or reducing the amount, and frequency, of intake of free sugars.

Conclusions

Consumption of free sugars is an important contributor to the global oral disease burden, in particular dental caries. Further, the burden is greater in less developed countries, where public health interventions, dental care options and fluoride exposure may be limited. Intake of free sugars should be limited to a maximum of ˂10% of daily TE. Dental professionals can educate patients on the risks associated with free sugars, components of a healthy diet and reducing/eliminating consumption of free sugars in accordance with updated recommendations. In addition, at a regulatory and global level, strategies to reduce caries may include revised and more explicit labeling, warning labels and imposition of taxes. Reducing intake of free sugars is an important initiative for global oral and systemic health.

References

  • 1.Te Morenga L, Mallard S, Mann J. Dietary sugars and body weight: systematic review and meta-analyses of randomised controlled trials and cohort studies. Br Med J 2013;346:e7492.
  • 2.World Health Organization. Guideline. Sugars intake for adults and children. Geneva: World Health Organization; 2015.
  • 3.Moynihan P. Sugars and dental caries: Evidence for setting a recommended threshold for intake1–3. Adv Nutr 2016;7:149-56.
  • 4.Mann J. The science behind the sweetness in our diets. Bull World Health Organ 2014;92:780-1. Available here.
  • 5.Stanhope KL. Sugar consumption, metabolic disease and obesity: The state of the controversy. Crit Rev Clin Lab Sci 2016;53(1):52-67.
  • 6.Pitts NB, Zero DT, Marsh PD, Ekstrand K, Weintraub JA, Ramos-Gomez F, Tagami J, Twetman S, Tsakos G, Ismail A. Dental caries. Nat Rev Dis Primers 2017;25(3):17030.
  • 7.Bibby BG, Krobicka A. An in vitro method for making repeated pH measurements on human dental plaque. J Dent Res 1984;63:906-9.
  • 8.Touger-Decker R, van Loveren C. Sugars and dental caries. Am J Clin Nutr 2003;78(suppl):881S–92S.
  • 9.Meier T, Deumelandt P, Christen O, Stangl GI, Riedel K, Langer M. Global burden of sugar-related dental diseases in 168 countries and corresponding health care costs. J Dent Res 2017;96:845-54.
  • 10.Keller MK, Kressirer CA, Belstrom D, Twetman S, Tanner ACR. Oral microbial profiles of individuals with different levels of sugar intake. J Oral Microbiol 2017;9:1355207.
  • 11.Giacaman RA. Sugars and beyond. The role of sugars and the other nutrients and their potential impact on caries. Oral Dis 2017.
  • 12.Mira A, Simon-Soro A, Curtis MA. Role of microbial communities in the pathogenesis of periodontal diseases and caries. J Clin Periodontol 2017; 44(Suppl. 18):S23–S38.
  • 13.Sanz M, Beighton D, Curtis MA, Cury JA, Dige I, Dommisch H, Ellwood R, Giacaman RA, Herrera D, Herzberg MC, Könönen E, Marsh PD, Meyle J, Mira A, Molina A, Mombelli A, Quirynen M, Reynolds EC, Shapira L, Zaura E. Role of microbial biofilms in the maintenance of oral health and in the development of dental caries and periodontal diseases. Consensus report of group 1 of the Joint EFP/ORCA workshop on the boundaries between caries and periodontal disease. J Clin Periodontol 2017;44(Suppl 18):S5-S11.
  • 14.Bowen WH, Burne RA, Wu H, Koo H. Oral biofilms: Pathogens, matrix, and polymicrobial interactions in microenvironments. Trends Microbiol 2017 Oct 30.
  • 15.Cai J-N, Jung J-E, Dang M-H, Kim M-A, Yi H-K, Jeon J-G. Functional relationship between sucrose and a cariogenic biofilm formation. PLoS ONE 2016;11(6):e0157184.
  • 16.Beaglehole R, Benzian H, Crail J, Mackay J. The oral health atlas: Mapping a neglected global health issue. 1st Ed. FDI World Dental Education & Myriad Editions, 2009.
  • 17.Marcenes W, Kassebaum NJ, Bernabé E, Flaxman A, Naghavi M, Lopez A, Murray CJL. Global burden of oral conditions in 1990-2010. A systematic analysis. J Dent Res 2013;92(7):592-7.
  • 18.Brook I. Brain abscess in children: microbiology and management. J Child Neurol 1995;10(4):283-8.
  • 19.Ratnayake N, Ekanayake L. Prevalence and impact of oral pain in 8-year-old children in Sri Lanka. Int J Paediatr Dent 2005;15(2):105-12.
  • 20.Krisdapong S, Prasertsom P, Rattanarangsima K, Sheiham A. School absence due to toothache associated with sociodemographic factors, dental caries status, and oral health-related quality of life in 12- and 15-year-old Thai children. J Pub Health Dent 2013;73(4):321-8.
  • 21.Malek Mohammadi T, Wright CM, Kay EJ. Childhood growth and dental caries. Community Dent Health 2009;26(1):38-42.
  • 22.Casamassimo PS, Thikkurissy S, Edelstein BL, Maiorini E. Beyond the dmft: the human and economic cost of early childhood caries. J Am Dent Assoc 2009;140(6):650-7.
  • 23.Moynihan PJ, Kelly SAM. Effect on caries of restricting sugars intake: Systematic review to inform WHO guidelines. J Dent Res 2014;93(1):8-18.
  • 24.Sheiham A, James WP. A new understanding of the relationship between sugars, dental caries and fluoride use: implications for limits on sugars consumption. Public Health Nutr 2014;17(10):2176-84
  • 25.Tierney M, Gallagher AM, Giotis ES, Pentieva K. An online survey on consumer knowledge and understanding of added sugars. Nutrients 2017;9:37.
  • 26.Bollard T, Maubach N, Walker N, Mhurchu CN. Effects of plain packaging, warning labels, and taxes on young people’s predicted sugar-sweetened beverage preferences: an experimental study. Int J Behav Nutr Phys Activity 2016;13:95.
  • 27.Silver LD, Ng SW, Ryan-Ibarra S, Taillie LS, Induni M, Miles DR, Poti JM, Popkin BM. Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study. PLoS Med 2017;14(4):e1002283.
  • 28.Chapple IL, Bouchard P, Cagetti MG, Campus G, Carra MC, Cocco F, Nibali L, Hujoel P, Laine ML, Lingstrom P, Manton DJ, Montero E, Pitts N, Rangé H, Schlueter N, Teughels W, Twetman S, Van Loveren C, Van der Weijden F, Vieira AR, Schulte AG. Interaction of lifestyle, behaviour or systemic diseases with dental caries and periodontal diseases: consensus report of group 2 of the joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases. J Clin Periodontol 2017;44 Suppl 18:S39-S51.
  • 29.Moynihan P, Makino Y, Petersen PE, Ogawa H. Implications of WHO Guideline on Sugars for dental health professionals. Community Dent Oral Epidemiol 2017 Nov 23.
  • 30.Goodwin M, Patel DK, Vyas A, Khan AJ, McGrady MG, Boothman N, Pretty IA. Sugar before bed: a simple dietary risk factor for caries experience. Community Dent Health 2017;34(1):8-13.
  • 31.Tan SF, Tong HJ, Lin XY, Mok B, Hong CH. The cariogenicity of commercial infant formulas: a systematic review. Eur Arch Paediatr Dent 2016;17(3):145-56.