Christine Wu, professor of pediatric dentistry and director of cariology at the University of Illinois at Chicago College of Dentistry, says dry, ready-to-eat, sugar-added cereals combine refined sugar and starch, and when these carbohydrates are consumed, bacteria in the dental plaque on tooth surfaces produce acids, which can cause cavities.
The study, conducted 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 percent apple juice or tap water.
Plaque pH, or acidity, was measured with a touch microelectrode between the premolar teeth before eating; at 2 and 5 minutes after eating; and then 2-30 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, while those who drank apple juice remained at pH 5.84 at 30 minutes, while water raised the pH to 6.02, Wu says.
Fruit juices are considered healthy food choices, but the added sugar can be a risk to dental health, Wu says.
"Our study results show that only milk was able to reduce acidity of dental plaque resulting from consuming sugary Froot Loops," said Naval, a fellow at the Centers for Disease Control and Prevention in Atlanta."
The findings were published in the Journal of the American Dental Association.