Diet, oral health: Why what you eat shapes your smile

Oral health is an essential component of overall well-being.

It has an impact on eating, speech, and social interactions and is strongly associated with health conditions such as diabetes and heart disease.

The World Health Organisation identifies oral diseases among the most prevalent noncommunicable diseases in the world, affecting many people.

It is usually common to think of oral hygiene as restricted to brushing and flossing, but do you know that the foods we choose to eat every day can increase or reduce our chances of developing gum disease and tooth decay or maintain a healthy smile?

Dental caries (tooth decay) and periodontal disease (gum disease) are two of the most common oral health issues deeply influenced by what we eat.

Sugars and starches feed harmful oral bacteria, which produce acids that erode tooth enamel, leading to cavities. 

Furthermore, poor nutrition weakens the body's ability to fight inflammation and heal tissues, increasing the risk of gum disease.

Saliva, one of the mouth’s strongest defenders, helps neutralise and wash away food particles.

Its production increases with hydration, fibrous foods, and fluoride intake. Reduced saliva flow, often due to aging or medication use, raises the risk of oral disease.

Foods that harm, protect

Research shows that free sugars are the main dietary culprit.

The frequency of sugar intake is just as important as its quantity.

Frequent snacking lowers the pH of the mouth, which is ideal for bacterial growth. 

Refined carbohydrates (e.g., white bread, white rice, spaghetti, noodles, pastries, cakes) and acidic drinks (e.g., soft drinks, energy drinks, alcoholic beverages, fruit juices) also erode the enamel.

On the positive side, protective foods can improve oral health. Fibrous fruits and vegetables stimulate saliva flow, dairy products help neutralise acids, and fluoride-rich foods such as tea strengthen the enamel.

Vitamin C and antioxidants also play a role in supporting gum health and reducing inflammation.
 

Do dietary patterns matter at all?

Beyond individual foods, overall dietary patterns shape oral health.

Higher incidence of dental caries and even oral cancer has been associated with the Western diet, which is heavy in processed foods and sugars. 

In contrast, the Mediterranean diet, which is rich in fruits, vegetables, whole grains, such as, unpolished maize, brown rice, fonio, wheat, oats, and healthy fats, has anti-inflammatory effects and is associated with better oral health-related quality of life.

Plant-based diets show mixed results; while high in antioxidants and fibre, their frequent acidic fruit intake and low dairy consumption may raise oral health risks. 

Vulnerable groups?

Certain populations are particularly vulnerable to diet-related oral problems.

Early childhood caries in children is linked to feeding practices.

Frequent sugary snacks, bottle feeding with sweetened liquids at night, and inadequate fluoride exposure significantly increased risk.

Parental education and early promotion of protective foods are essential preventive measures.

Aging naturally reduces saliva production.

Combined with tooth loss or dentures, which make chewing fibrous foods difficult, older adults face higher risks of oral disease and nutrient deficiencies.

There is a two-way relationship between chronic conditions, especially diabetes, and oral health.

Poor blood sugar control increases gum disease risk, while gum disease makes diabetes more difficult to control. Furthermore, the use of multiple medications often reduces saliva flow, worsening caries risk.

Conclusion

Healthy eating is essential for protecting both oral and overall health.

Reducing sugar intake, choosing more protective foods, and adopting balanced eating habits can significantly lower the risk of gum disease and tooth decay. 

For practical guidance on making healthier food choices, individuals are encouraged to refer to the Ghana Food-Based Dietary Guidelines (available online) or seek personalised advice from a registered dietician or nutritionist.

Department of Dietetics, 
School of Biomedical and Allied Health Sciences, University of Ghana.