A dynamic relation exists between sugars and oral health. Dietary choices impact various aspects of oral health, including tooth integrity, saliva pH, and plaque pH. When sugars and fermentable carbohydrates are broken down by salivary amylase, they provide a substrate for oral bacteria, leading to a decrease in saliva pH and the initiation of tooth demineralization. Many factors in addition to sugars affect the caries process, including the form of food or fluid, the duration of exposure, nutrient composition, sequence of eating, salivary flow, presence of buffers, and oral hygiene. Since the introduction of fluoride, the incidence of caries worldwide has decreased, despite increases in sugars consumption. The primary public health measures for reducing caries risk, from a nutrition perspective, are the consumption of a balanced diet and the use of topical fluorides and consumption of fluoridated water.

Introduction

Humans naturally enjoy sweet flavors, but switching from natural nectar to refined sugar has led to a big increase in tooth decay. Sugars are the main cause of tooth decay. When bacteria in our mouth feed on sugars, they produce acid that damages our teeth. The two main bacteria involved in causing decay are mutans streptococci and lactobacilli. According to the World Health Organization in 2015, free sugars include sugars added to foods and drinks by manufacturers, as well as sugars naturally found in honey, syrups, and fruit juices which can all contribute to tooth decay.

Tooth decay was first talked about in Miller's theory in 1890. It's one of the most common dental problems worldwide, affecting about 35.3% of people of all ages. For many, tooth decay starts early and progresses without causing symptoms until it's more advanced and leads to pain and tooth loss. Tooth decay not only affects people's health but also causes problems for society.

Background

Tooth decay is very common in both rich and poor countries. In 2010, about 3.9 billion people had oral problems, and untreated tooth decay was the most common issue worldwide. Even though tooth decay has gotten better in the last 20 years, it's still a big problem that affects many people. Sugars in our food are the main reason why tooth decay happens. Bacteria in our mouth turn sugars into acid, which damages our teeth. Brushing our teeth and using fluoridated toothpaste or water can help reduce tooth decay.^1,2

Cariogenic process

The original studies showed that the enamel on our teeth gets weaker when the area around the tooth becomes more acidic. This acidity is mostly caused by certain bacteria. Sugars, especially sucrose, help these bacteria grow, and they are the main reason why tooth decay happens. Sucrose is particularly bad because it gets fermented by bacteria in our mouth, which makes acid that damages our teeth. After we eat sugars like glucose or fructose, the pH in our mouth drops quickly, making it more acidic, which leads to our teeth losing minerals over time.³

Clinical and epidemiologic studies of dental caries in Europe

A dramatic decrease in the prevalence of dental caries has occurred in developed countries. During the 1990s in the Netherlands, > 50% of 5-y-old children were cavity free. The distribution of the children according to their caries experience is skewed, and 60–80% of the decay is found in 20% of the population in both Europe and the United States.⁴

Caries incidence in the United States

Dental caries is one of the most common childhood diseases in the United States. It is 5 times more common than asthma and 7 times more common than hay fever and its prevalence increases with age throughout adulthood. Of children aged 5–9 y, 51.6% have had ≥ 1 filling or caries lesion; of those aged 17 years, the proportion is 77.9%; 85% of adults aged >18 years have had caries. One of the health objectives for the United States in Healthy People 2010 is the further reduction of dental caries in all age groups through public health initiatives and improved access to care. The goal for children is to reduce the incidence of decay to 11%; for untreated caries, the goal for children and adults is to reduce the incidence to 9% of the population.^4,5

Economic burden of adult caries

Tooth decay causes a lot of problems for people and society, like pain, difficulty eating and talking, and feeling embarrassed in social situations. It really affects people's quality of life. Treating oral problems is expensive, ranking fourth in cost among diseases in many rich countries. In some places like Germany and Japan, dental care costs more than treating other diseases, sometimes even more than cancer. Treating tooth decay in poorer countries costs a lot too, often more than what's available for all healthcare for children in those countries.^4,6

WHO guideline

The WHO (2015) guideline aims to give advice on how much sugar intake people should have to lower the chances of getting certain diseases. Those guidelines mainly focus on preventing and controlling tooth decay. The WHO explains that tooth problems are very common worldwide and that treating them can be expensive, often costing more than what's available for children's healthcare in many poorer countries. Studies show that people are more likely to get tooth decay when they eat more than 10% of their energy from sugar, compared to when they eat less than 10%.⁶

An optimum intake of sugars?

World Health Organization (WHO) and Committee on Medical Aspects of Food policy, approach is to set the minimum average population level of a risk factor that minimizes a disease. Thus, it has been recommended that free sugar consumption should be below 15 kg per person per year in industrialized countries.⁶

The impact of fluoride on the sugar-caries relationship

Fluoride helps reduce tooth decay by about 25% in 12- year-old kids when they eat the same amount of sugar. Many countries have seen less tooth decay in children since the 1970s because more kids are using fluoride toothpaste.^7,8

Limitations of the study

Extensive searches of the historical, as well as current literature on sugars and caries were carried out. The limitations of the study related to the absence of defined valid data on the dose-response relationship of adult caries when sugar intakes change. Therefore, our findings depend on data from children together with longitudinal data on an annual basis.

Conclusion

Tooth decay is a problem caused by what you eat. Many studies show that sugars in food are the main reason why tooth decay happens. Certain bacteria and other things can also make tooth decay worse, but sugars in food are the main reason why it happens.

Encouraging healthy eating and cutting down on sugary drinks is important for controlling sugar intake in teenagers.