Why Dental Health Authorities Recommend Dairy Products

What we eat affects our teeth

The foods we eat impact both our dental and overall health.^1,2 The Canadian Dental Association highlights the importance of a nutritious balanced diet for our dental health as well as our general health.¹  They encourage people to choose nutritious snacks that won’t harm teeth such as plain milk, yogurt, cheese, fruit, raw vegetables, hard-boiled eggs, nuts, and seeds. They also point out that without the right nutrients, teeth and gums can become more susceptible to tooth decay and gum disease. 

Additionally, the American Dental Association notes that the first signs of poor nutrition often show up in the mouth.² They advise that foods such as hard or sticky candies, sweet baked goods like cookies, cakes, muffins and chips are a concern for dental health, not only because they offer little nutritional value, but also due to the amount and type of sugar they contain. Bacteria in our mouth feed off these sugars and release acids, which can ultimately lead to tooth decay.  

Dairy nutrition and dental health

Milk products contain a unique combination of several nutrients that play a role in supporting dental health throughout life. Dairy foods such as milk, yogurt and cheese are important sources of a number of nutrients that contribute to dental health, including dietary calcium, phosphorus, and vitamin D as well as the milk protein, casein.^3,4

Calcium, phosphorus, and vitamin D

Cow’s milk contains both calcium and phosphorus, which are two key minerals that aid in the formation and maintenance of teeth and bones. Research shows that the calcium and phosphorus found in cow’s milk help with the remineralization of tooth enamel and dentine and to resist demineralization.⁴ Cow’s milk in Canada is fortified with Vitamin D, which enhances calcium and phosphorus absorption and utilization, and also helps build strong teeth and bones.

The role of protein

Research shows that casein, the main protein in milk, reduces the demineralization of teeth, playing a protective role.⁴ Proteins, which help build and repair body tissues, adhere well to the enamel surface of teeth. Casein, in particular, appears to prevent the adherence of bacteria and components of saliva to dental enamel, thus reducing the adherence of plaque.

Experiments suggest that other milk components such as fat, may also reduce the ability of acid-forming plaque bacteria to adhere to enamel, which may in turn reduce the risk of tooth decay.

How cow’s milk compares to other beverages

The Canadian Dental Association recommends water, plain milk, and buttermilk as beverages and suggests limiting sugary drinks.¹ Based on current evidence from various types of studies, cow’s milk can be considered non-cariogenic, meaning that it does not lead to dental cavities.⁴ Several lines of evidence also suggest a possible anti-cariogenic effect. More recent observational studies indicate that milk is associated with a lower risk of dental cavities.

While cow’s milk contains the natural sugar lactose, it has been found to be the least cariogenic of dietary sugars.⁴ A review on how cow’s milk, human milk and infant formulas compared to sucrose in animal models concluded that cow’s milk is the least cariogenic.⁵  On the other hand, many plant-based beverages contain added sugars which are considered cariogenic.⁶ 

Evidence from multiple studies indicates that milk and yogurt are not linked with dental erosion while soft drinks are associated with 2.5 times the risk of dental erosion.⁷ Researchers suggest that this is likely due to the sugar content, low pH and high acidity of soft drinks. Tooth erosion occurs due to the loss of the outer surface of tooth enamel which happens with low surface pH. Several studies have shown that the fall in plaque pH after drinking milk is negligible compared with the fall in pH after drinking sugar solutions of either sucrose or lactose.⁵ Falls in pH for lactose were smaller than those for sucrose. Based on this, researchers have suggested drinking milk instead of soft drinks as a practical strategy to help reduce the risk of dental erosion.⁷ 

Dairy probiotics in fermented milk and yogurt

Research also suggests that consuming dairy products that contain probiotics, such as fermented milk and yogurt, may benefit oral health and reduce the risk of cavities.^8,9 A comprehensive review found that in general dairy probiotics had a number of effects considered beneficial, such as reducing certain bacteria, increasing salivary pH and influencing plaque index.⁹

Why cheese is recommended as a snack 

Of course, many factors contribute to our dental health, such as our brushing and flossing habits as well as what we eat. Dental Hygiene Canada suggests eating hard cheese after meals or as a snack as a practical strategy to help prevent tooth decay.¹⁰ They explain that cheese helps to protect teeth from bacteria and also contains calcium which helps to build and maintain teeth.