Drinking milk after breakfast may ward off cavities

Drinking a glass of milk after having sugary cereals for breakfast can prevent tooth cavities, scientists, including one of Indian-origin, have found.
Dry ready-to-eat, sugar-added cereals combine refined sugar and starch. When those carbohydrates are consumed, bacteria in the dental plaque on tooth surfaces produce acids, said principal investigator of the study, Christine Wu, professor of pediatric dentistry and director of cariology at the University of Illinois at Chicago College of Dentistry.
According to the new research, published in the Journal of the American Dental Association, consuming a glass of milk after eating sugary breakfast cereal reduces plaque acid levels and may prevent damage to tooth enamel that leads to cavities.

The new study, performed by Wu's former graduate student Shilpa Naval, involved 20 adults eating 20 grams of dry Froot Loops cereal, then drinking different beverages - whole milk, 100 per cent apple juice, or tap water.
Plaque pH, or acidity, was measured with a touch microelectrode between the premolar teeth before eating; at two and five minutes after eating; and then two to 30 minutes after drinking a liquid.
The pH in plaque dropped rapidly after consuming cereal alone, and remained acidic at pH 5.83 at 30 minutes. A pH below 7 is acidic; a pH greater than 7 is basic. Pure water has a pH close to 7.

Participants who drank milk after eating sugary cereal showed the highest pH rise, from 5.75 to 6.48 at 30 minutes. Those who drank apple juice remained at pH 5.84 at 30 minutes, while water raised the pH to 6.02.

Fruit juices are considered healthy food choices, but the added sugar can be a risk to dental health, Wu said.
"Our study results show that only milk was able to reduce acidity of dental plaque resulting from consuming sugary Froot Loops," said Naval, who is currently a fellow at the Centers for Disease Control and Prevention in Atlanta.
"We believe that milk helped mitigate the damaging effect of fermentable carbohydrate and overcome the previously lowered plaque pH," Naval said.

Milk, with a pH ranging from 6.4 to 6.7, is considered to be a functional food that fights cavities because it promotes tooth remineralisation and inhibits the growth of plaque, Wu said.
Wu said most consumers think that since milk is considered to be cavity-fighting, acid production by plaque bacteria can be minimised by mixing it with cereal.
However, in an unpublished study in her lab, it was discovered that the combination of Froot Loops and milk became syrupy. Eating cereal combined with milk lowered plaque pH to levels similar to that obtained after rinsing with a 10 per cent sugar solution.

Eating sugar-added cereal with milk, followed by drinking fruit juice is thus a highly cavity-causing combination, Wu said.