Chapter 8: Milk, Yoghurts and Dental Caries

Milk is an important part of the human diet; after weaning, cow's milk (bovine milk) predominates and this chapter considers the effect of bovine milk on dental caries. Yoghurt, which is a milk product, is also considered here. Several published reviews have concluded that milk is of very low cariogenicity and may have some caries protective potential. For example, WHO reviewed the strength of the evidence in 2003 and concluded that a "decreased risk" of dental caries from milk was "possible." The evidence comes from several types of study: epidemiological studies (interventional and observational), animal experiments, plaque pH studies, and in vivo and in vitro enamel and dentine slab experiments. More recent observational epidemiological studies have adjusted for potential confounders and have reported that milk consumption is associated with lower caries experience or incidence. Other types of study generally support this conclusion. Reasons for these favourable caries-related properties include the lower acidogenicity of lactose compared with other dietary sugars and the protective effects of calcium, phosphate, proteins, and fats. There is less research concerning yoghurts but it is likely that the cariogenic potential of plain yoghurt is similar to that of milk. The addition of sucrose to milk increases caries risk.