Dental caries is an international public health problem with multiple causes that vary with age and location.
Dental caries (dental plaque) bacteria thrive when fed sugars, producing acids which demineralize tooth enamel. A diet low in free sugars is a key strategy in protecting against tooth caries.
Relationship Between Sugar Consumption and Dental Caries: A Systematic Review
Dental caries is a chronic, progressive oral disease, which disproportionately impacts poor and vulnerable populations that lack access to preventive health services. According to scientific literature, free sugars play an integral role in both its onset and progression; recent WHO recommendations call for restricting intake to 10% of energy intake as an appropriate limit for free sugars intake.
This systematic review seeks to establish whether reducing sugar intake decreases dental caries prevalence and severity. A PICO question was created in order to identify cohort studies and randomized controlled trials which studied how different patterns of sugar exposure influence dental caries incidence across any age population; intake of free sugars included honey, syrups, fruit juice concentrates etc.
Background
Research studies conducted with various populations over time have repeatedly demonstrated the correlation between diets high in sugars and dental caries, a noncommunicable disease, and their consumption. Accordingly, The World Health Organization (WHO) suggests restricting free sugars intake to no more than 10% of total energy intake – considered a strong recommendation by WHO.
Sugar consumption promotes cariogenic bacteria growth in the oral cavity and their metabolism produces acids that damage dentin and enamel, leading to demineralization and dental caries formation. While other factors, including education, toothbrushing frequency and fluoride use may influence dental caries formation, sugar is still the main contributor. Thus, research needs to focus on developing strategies against early life exposure to sugar as well as high frequency sugar consumption throughout daily life.
Methods
Sugars, whether natural or added, encourage cariogenic bacteria that lead to tooth enamel and dentin degradation and formation of acids which demineralize and lead to dental caries.
Numerous studies have reported data on the correlation between sugar intake and dental caries; however, their results vary. This may be because different variables influence these results such as length of follow up period and caries prevalence or severity rates; method of sugar measurement/reporting; as well as method of diet assessment.
Although results have varied considerably, all available evidence supports a correlation between diet-rich in sugars and dental caries. On this basis, WHO adopted new dietary guidelines which set a 10% limit of energy consumed from sugars by both children and adults (3, 4). This recommendation can only be considered strong.
Results
Studies showing a correlation between sugar consumption and dental caries was consistent in both cross-sectional and longitudinal analyses, independent of age or frequency of toothbrushing.
Log-linear dose-response relationship analysis revealed that every additional 5-g/day intake of sugar led to an additional one percent chance of dental caries over three years, regardless of caries groups (high vs low). This correlation held true even among higher caries groups.
Dietary free sugars were identified as the primary contributor to dental caries. This includes added monosaccharides such as sucrose or fructose as well as naturally occurring polysaccharides such as fructose, galactose and lactose found in foods (grains, fruits and vegetables) or added naturally into whole food sources like honey and syrups such as high fructose corn syrups – regardless of adequate fluoride exposure levels. The correlation was independent from this factor alone.
Conclusions
Dental caries is a widespread condition with serious consequences for individuals and societies. While preventable, it requires multifaceted approaches in order to decrease sugars in the diet based on each country and community’s context and reality.
Sugar consumption has been associated with an increase in both incidence and severity of dental caries in both deciduous and permanent teeth, with adolescents showing particularly strong associations. Subgroup analysis by age revealed various associations; adolescents showed particularly strong ones.
Strategies to limit sugar availability and consumption should be implemented across communities, particularly children’s and adolescent’s environments. Such efforts may include educational family interventions and measures restricting promotional of foods with added sugars.
