Does sugar consumption contribute to the development of dental caries (tooth decay)?

Sugar Consumption and Dental Caries

Yes, sugar directly causes dental caries (cavities) through a well-established biological mechanism where oral bacteria ferment sugars to produce acids that erode tooth enamel. 1

Mechanism of Cavity Formation

• Dental caries is caused by the fermentation of sugar by oral bacteria that accumulate as dental plaque, generating acid that erodes dental enamel 1
• This acid production leads to demineralization of tooth enamel and eventually cavity formation if the process continues unchecked 2
• Acidic sugar-containing drinks are particularly harmful as they contribute to both acid erosion and provide fermentable substrate for bacteria 1

Evidence Strength and Relationship

• The relationship between sugar consumption and dental caries is dose-dependent, with a log-linear relationship between sugar intake and progressive caries development 2
• Multiple cohort studies demonstrate that higher sugar consumption correlates with increased caries risk 1
• In one study, each additional 5g of sugar intake was associated with a 1% increase in the probability of developing caries 1
• Another study found participants were 2.99 times more likely to have higher caries when free sugar consumption was 16% of energy intake compared to when it was below 10% 1

Sugar Consumption Thresholds and Caries Risk

• The World Health Organization (WHO) recommends limiting free sugars to less than 10% of total energy intake, and ideally below 5% 1
• The UK Scientific Advisory Committee on Nutrition recommends no more than 5% of food energy from free sugars 1
• Studies show that when sugar consumption is below 10% of energy intake, caries development is significantly lower 1
• In Finnish children, those who remained cavity-free had sugar intake below 9% of energy, while those who developed caries consumed more than 10% 1

Types of Sugar and Their Cariogenic Potential

• All fermentable sugars can cause caries, but sucrose is considered the most cariogenic, followed by glucose and fructose 3
• Free sugars (monosaccharides and disaccharides added to foods and beverages by manufacturers, cooks, or consumers, plus sugars naturally present in honey, syrups, fruit juices) are particularly problematic 1
• Brown sugars are as cariogenic as white sugars 3

Factors That Modify Caries Risk

• Frequency of sugar consumption may be even more important than total amount consumed 4
• Fluoride in drinking water (1 mg/l) or toothpaste can significantly reduce caries risk even with sugar consumption 1
• Good oral hygiene to remove plaque can reduce the cariogenic effects of sugar 1
• Limiting sugar-containing eating occasions to no more than four times daily can help reduce caries risk 1
• Saliva flow provides protective effects through buffering acids and providing minerals for remineralization 5

Preventive Strategies

• The three most practical approaches to caries prevention are: sugar control, fluoride use, and fissure sealing 6
• Without sugar, dental caries would be negligible 6
• Substituting non-cariogenic sweeteners for sugars in foods and drinks can help reduce caries risk 3
• Developing sugar-free snacks and drinks is an important preventive strategy 3
• Reducing added sugars in commonly consumed foods would have population-level benefits 3

High-Risk Populations

• Children are particularly vulnerable to caries from sugar consumption 1
• A recent report found 27% of 5-year-olds have three to four teeth decayed, missing, or filled 1
• The risk of caries is much higher in low socioeconomic groups, particularly migrants 1
• Allowing toddlers to have trainer cups or dummies containing sugary drinks significantly increases caries risk 1