Next time you rush for the mouthwash or extra strong mints to hide that embarrassing condition affecting 1 in 4 people- halitosis or bad breath- try plain sugarless yogurt say scientists.

In a study, researchers from Tsurumi University in Yokohama, Japan, found that eating plain “Greek style” live yogurt, rich in Streptococcus thermophilus and Lactobacillus bulgaricus combatted the presence of hydrogen sulfide, the compound that is a major component in bad breath.

Researchers gave twenty-four volunteers identical instructions for oral hygiene, diet and medication intake. They were asked to refrain from eating yogurt and foods containing streptococci and lactobacilli for two weeks.

Researchers then took saliva and tongue coating samples to measure bacteria levels and odor-causing compounds, including hydrogen sulfide.

During the second part of the study, the volunteers then consumed 90 grams of yogurt twice a day for six weeks. Samples showed at the end of six weeks hydrogen sulfide levels had decreased in 80 percent of volunteers who had bad breath.

An additional result showed that plaque and the gum disease, gingivitis were significantly reduced following the yogurt-eating phase.

Although Bruce Paster, senior staff member in the department of molecular genetics at The Forsythe Institute in Boston, commented that the research may have ignored important factors in bad breath. "Typically, the bacterial microbiota and their end products are the culprits for the bad breath," he said. However, "in theory," he added, "their hypotheses may be valid. For example, the odor-causing species may have been replaced by some 'good' species in the yogurt."

Dr Nigel Carter, chief executive of the British Dental Health Foundation, said: "The foundation has long been drawing people's attention to sugar-free yogurts as a healthy snack, so it is pleasing to hear that it may have oral health benefits we were previously unaware of.

"Frequent consumption of sugary snacks is the principal cause of tooth decay, which can cause a great deal of pain and discomfort.

"Although this research is still in the early stages there is no doubt that sugar-free yogurts provide a much healthier alternative to sweets and chocolate, and we would encourage snackers to incorporate them into their diet."