Nutrition, dairy foods and dental health

Happy kid with glass of milk image

By Rivkeh Haryono, Nutrition Scientist at Dairy Australia

Why is nutrition important in dental health?

A healthy diet means consuming foods from the five food groups outlined in the 2013 Australian Dietary Guidelines.1 However, the Australian Health Survey (AHS) shows we’re eating too many junk foods – approximately one third of our energy intake comes from alcohol, cakes, muffins, confectionery, pastries and soft drinks.2 Alarmingly, 34% of the population consume sugar-sweetened beverages which includes soft drinks, sports drinks and juices.3 It’s therefore not surprising that dental diseases are a common and costly health problem.

We all know that dental hygiene is important for healthy teeth and gums, but a healthy diet is also crucial in preventing dental diseases. In a recent survey*, the top nutrition advice from dentists was around limiting sugary food and drinks and this is with good reason – the association between intake of sugars and dental caries is most researched when it comes to nutrition and dental health.

We know it’s important to limit the amount of sugar and sugary foods in the diet, but it’s also important to reduce how often these are consumed. The more often teeth are exposed to these foods, the more time bacteria have to produce lactic acid, leading to demineralisation of the enamel and development of caries.4  

Dietary advice should also focus on limiting acidic drinks. For example, while a diet soft drink may seem like a better option due to the low sugar content, this is not necessarily the case. All soft drinks are acidic and frequent sipping means greater exposure to teeth and an increased risk of dental erosion.5,6 This also goes for other acidic drinks such as sports drinks, energy drinks, fruit juice and wine.

The form of the food should also be considered. Dried fruit should be limited as this can adhere to teeth, increasing the risk of cavities.7 On the other hand, fresh fruit and vegetables are protective as they contain phosphates and phytate which have cariostatic properties,8 while wholegrain foods and nuts are similarly protective as they require greater effort when chewing, increasing salivary flow.

It’s also important recommendations focus on other teeth friendly foods, such as milk, yoghurt and cheese. 

What is the role of dairy foods in dental health?

A body of evidence shows dairy foods play a specific role in dental health. A cross-sectional study of 2,058 Japanese children found that the highest consumers of yoghurt had a lower prevalence of dental caries,9 while a recent meta-analysis identified milk and yoghurt protect against tooth erosion.10 The nutrients in dairy foods have also been shown to protect against gum disease. In a recent study of 3,287 Danish adults, those with adequate calcium intakes, whey intake greater than 9.6g/d and casein intake of 32 g/d were less likely to develop periodontitis.11

The beneficial effects of milk, yoghurt and cheese can be attributed to the teeth- friendly nutrients they contain including calcium, casein and phosphorus. In addition, plaque pH studies show lactose, the sugar naturally found in milk, does not increase plaque acidity and is non-cariogenic, especially when compared to other sugars, such as fructose.12

Hard cheeses are thought to have the highest cariostatic properties as consumption stimulates salivary flow, neutralising the acid pH of the mouth following exposure to sugar,13 so a small amount is recommended after meals. Cheese has been shown to increase the concentration of calcium in saliva and plaque, helping to restore the enamel that is lost after consuming acidic foods or beverages.

Using this research in practice

Dentists and dental hygienists play a crucial role in the provision of nutrition advice to their patients and it is important they extend advice to include consumption of teeth-friendly foods.  

Along with recommendations to reduce intake of added sugars and acidic drinks, dentists and dental hygienists should advise that tap water or milk are the preferred drinks, while fresh fruit and vegetables, nuts, yoghurt and cheese are the perfect snacks for healthy teeth.   

For further information on dental health, visit the Australian Dental Association (ADA) website

*A survey of 101 Australian dentists was completed in October 2015 by IMSHealth.


References

1. National Health and Medical Research Council. Australian Dietary Guidelines, Canberra: Commonwealth of Australia; 2013.

2. Australian Bureau of Statistics. Australian Health Survey: Nutrition First Results - Foods and Nutrients, 2011-12. Cat 4364.0.55.007. Canberra; http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/4364.0.55.007~2011-12~Main%20Features~Discretionary%20foods~700 accessed 11.03.16

3. Australian Bureau of Statistics, 2015. Nutrition First Results - Foods and Nutrients, 2011-12. Consumption of sweetened beverages. Canberra; http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/4364.0.55.007main+features7102011-12.

4. Moynihan P, Petersen P. Diet, nutrition and the prevention of dental diseases. Public Health Nutr. 2004;7(1a).

5. Tahmassebi JF, Duggal MS, Malik-Kotru G, Curzon MEJ. Soft drinks and dental health: a review of the current literature. J Dent 2006;34:2–11.

6. Li H, Zou Y, Ding G. Dietary Factors Associated with Dental Erosion: A Meta-Analysis. PLoS ONE. 20127(8): e42626

7. National Health and Medical Research Council. Fruit [Internet]. Canberra, Commonwealth of Australia, 2015.  Available: https://www.eatforhealth.gov.au/food-essentials/five-food-groups/fruit

8. Moynihan P. Foods and factors that protect against dental caries. Nutr Bull 2000 25(4); 281-286

9. Tanaka K, Miyake Y, Sasaki S. Intake of dairy products and the prevalence of dental caries in young children. J Dent. 2010;38(7):579-83.

10. Salas MM, Nascimento GG, Vargas-Ferreira F, Tarquinio SB, Huysmans MC, Demarco FF. Diet influenced tooth erosion prevalence in children and adolescents: Results of a meta-analysis and meta-regression. J Dent. 2015;43(8):865-75. doi: 10.1016/j.jdent.2015.05.012. Epub 2015 Jun 7.

11. Adegboye A, Boucher B, Kongstad J, Fiehn N, Christensen L, Heitmann B. Calcium, vitamin D, casein and whey protein intakes and periodontitis among Danish adults. Public Health Nutr. 2015;19(03):503-10.

12. Telgi RL, Yadav V, Telgi CR, Boppana N. In vivo dental plaque pH after consumption of dairy products. Gen Dent. 61(3):56-9.

13. Kashket S, DePaola D. Cheese consumption and the development and progression of dental caries. Nutr Rev. 2002;60(4):97-103.