A new study has revealed that drinking a moderate amount of alcohol, say a glass of wine daily, protects against the development of gallstones – in fact, it can cut the risk by nearly a third.

Gallstones form in the gallbladder from bile and are generally made up of hardened cholesterol. They can be very painful and treatment is surgery to remove the gallbladder.

Lead researcher Dr Paul Banim of University of East Anglia said alcohol was known to increase levels of "good" HDL cholesterol which was also known to be protective against cardiovascular disease and which could alter the composition of cholesterol in the bile.

He said that excessive alcohol intake can cause health problems but quantifying how much alcohol reduces the risk of gallstone development allows doctors to give proper guidance. In fact, the researchers came to the conclusion after analysing the diets of 25,639 people over ten years. During that time 267 of the volunteers developed gallstones.

Overall, those who consumed two units of alcohol a day saw their chances of developing gallstones fall by one third. Every unit drunk a week cut the chances by three per cent, the study found.

"These findings significantly increase our understanding of the development of gallstones. Once we examine all the factors related to their development in our study in Britain, including diet, exercise, body weight and alcohol intake, we can develop a precise understanding of what causes gallstones and how to prevent them," the British media quoted Dr Andrew Hart as saying.