British Dental Journal 216, 5 (2014)
Published online: 10 January 2014 | doi:10.1038/sj.bdj.2013.1268

Fewer teaspoons of sugar a day will cut decay

New research from Newcastle University recommends cutting down on sugar as part of a global initiative to reduce tooth decay.1

Since 1990 the World Health Organisation (WHO) has recommended that intake of 'free sugars' should be less than 10% of total calorie intake. Free sugars are those that are added to food as well as those naturally present in honey, syrups, fruit juices and fruit concentrates.

Fewer teaspoons of sugar a day will cut decay


The Newcastle University study, commissioned by the WHO and published last month in the Journal of Dental Research, recognises the benefit of this threshold by showing that when less than 10% of total calories in the diet is made up of free sugars there are much lower levels of tooth decay. The new research findings go even further, suggesting that halving this threshold for sugars to less than 5% of calories – around five teaspoons a day - would bring further benefits, minimising the risk of dental cavities throughout life.

Professor Moynihan, Professor of Nutrition and Oral Health at Newcastle University, said: 'In the past, judgements on recommended levels of free sugars intake were made based on levels associated with an average of three or fewer decayed teeth in 12-year-olds. However, tooth decay is a progressive disease – by looking at patterns of tooth decay in populations over time, we now know that children with less than three cavities at age 12, go on to develop a high number of cavities in adulthood'.

The researchers scrutinised all the studies that had looked at relationships between amounts of sugars consumed and levels of dental caries. They found 55 relevant studies worldwide, dating back to 1950. Combined analysis of the data was limited because of the variation in how the data were reported but there was strong consistency across studies and evidence of a large size effect.

Considering the studies which examined the influence of fluoride, the researchers found that while it does protect teeth, people living in areas with fluoridated water and/or using fluoride toothpaste still got dental caries.

Professor Moynihan concluded: 'We need to make it easier for people to make healthier choices when it comes to sugars by ensuring that options lower in added sugars are made widely available in schools, shops and the workplace'.



  1. Moynihan P J, Kelly S A. Effect on caries of restricting sugars intake: systematic review to inform WHO guidelines. J Dent Res 2013; DOI: doi:10.1177/0022034513508954. | Article |


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