Why might a child with PKU have an increased incidence of dental caries?

A child with phenylketonuria (PKU) is typically placed on a specialized diet that is low in phenylalanine, which often entails a significant restriction of protein sources. As a result, these children may rely on foods that are higher in carbohydrates and lower in protein compared to a typical diet. This carbohydrate-rich diet can include processed foods and sweeteners that are less likely to support good dental health.

High carbohydrate consumption, particularly from simple sugars found in many processed foods, can contribute to an increase in dental caries due to the way bacteria in the mouth metabolize these sugars, producing acids that erode tooth enamel. Furthermore, if a child’s diet includes foods high in added sugars to compensate for low protein, this can elevate the risk for dental decay.

In contrast, a diet that is high in protein typically has less of a negative impact on dental health because protein sources do not contribute to the same level of acid production in the mouth. Therefore, while the diet for PKU is structured to meet the child’s nutritional needs and limit phenylalanine, it can inadvertently lead to a greater risk of dental caries if it is high in carbohydrates and low in stringent dental health considerations.