Drinking milk after eating sugary foods may cut cavity risk

Washing down sugary breakfast cereal with milk after eating may help cut tooth decay, a new small study finds.

Drinking milk after eating ready-to-eat cereal was found to reduce plaque acid levels and may prevent damage to tooth enamel that leads to cavities, researchers from University of Illinois at Chicago College of Dentistry said.

After eating starchy, sugary cereal, bacteria in the plaque on tooth surfaces produces acids, said lead researcher Christine Wu, professor of pediatric dentistry and director of cariology. Reports have shown that eating carbohydrates four times daily, or in quantities greater than 60 grams per person per day, increases the risk of cavities.

Wu and her research team recruited 20 adults, who ate 20 grams, or about a cup, of a sugary cereal and then drank 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 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.

Subjects who drank milk after eating the 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.

Prior studies have shown that eating cheese after a sugary meal reduces acid production, the researchers said, and that consumers can modify their diet in such a way as to prevent the cavity-causing effects of sugary foods.