Dundee: Cooking methods may increase the acidity of foods, therby increasing dental erosion, researchers at the University of Dundee have found. The research was prompted by the premise that vegetarians may be more at risk from dental decay because the vegetables and fruits they eat are higher in acids than foods in a usual diet.

They looked at the classic French dish Ratatouille, a vegetable stew which has a high tomato, garlic and olive oil content, and discovered that roasting the vegetables first made it almost as acidic as some carbonated drinks.

The research team was led by Dr Graham Chadwick in the School of Dentistry, which found that although the dish was acidic, roasting it made it more so.

Dental erosion is caused by the direct contact of acid with the teeth. The acid destroys tooth tissues and can result in severe destruction, leading to the need for expensive and time-consuming dental treatment.

The Dundee team also investigated whether the cooking method had an impact on the acidities of individual vegetables and fruits. They found the cooking method had no impact on the acidity of tomatoes or onions, but roasting resulted in more acidic aubergines, green peppers and courgettes. Red peppers were more acidic when stewed.

The research is published in the current edition of the European Journal of Prosthodontics and Restorative Dentistry. It is one in a series of research projects being carried out at the University looking into the causes of dental erosion.