Elite athletes have high rates of oral disease - even though they brush their teeth more frequently than most people, scientists say.
Researchers quizzed 352 Olympic and professional athletes across 11 Great Britain teams about their dental habits and reviewed their dental records.
Nearly half had untreated tooth decay and the large majority showed early signs of gum inflammation, results revealed.
But almost 100 per cent reported brushing their teeth the recommended twice a day, compared to only 75 per cent of the general population.
Researchers blamed the high consumption of products such as chocolate bars, sports drinks and flavoured gels - which athletes use daily for energy and recovery.
Exercise can also strip athletes of saliva, which is crucial for shifting plaque on teeth, it has previously been found.
The research, by The University College London (UCL) Eastman Dental Institute, was published in the British Dental Journal.
The team quizzed athletes representing Great Britain, including from teams for rugby, swimming football, rowing, hockey, sailing and athletics.
The researchers found the athletes regularly use sports drinks (87 per cent), energy bars (59 per cent) and energy gels (70 per cent), and the majority were aware the products could damage their teeth.
No products were mentioned, however it is widely known athlete often endorse brands and report using their products.
For example, Mo Farah has previously partnered with Lucozade Sport and Jessica Ennis was once an ambassador for Powerade.
The researchers also asked athletes what they did to keep their mouth clean, and 44 per cent reported flossing - more than the 21 per cent in the general population.
The athletes provided dental check-ups so the researchers could assess their oral health.
Despite good oral hygiene, the dental records revealed substantial amounts of oral disease.
A total of 49.1 per cent had untreated tooth decay, the large majority showed early signs of gum inflammation.
Almost a third (32 per cent) reported that their oral health had a negative impact on their training and performance.
This is similar to the general population, according to the study authors.
Dr Julie Gallagher, the lead researcher, said: 'We found that a majority of the athletes in our survey already have good oral health related habits in as much as they brush their teeth twice a day, visit the dentist regularly, don't smoke and have a healthy general diet.
'However, they use sports drinks, energy gels and bars frequently during training and competition; the sugar in these products increases the risk of tooth decay and the acidity of them increases the risk of erosion.
'This could be contributing to the high levels of tooth decay and acid erosion we saw during the dental check-ups.'
Three in ten of the athletes were considered to consume too much sugar from cakes, biscuits and sweets, the team said.
And it may prove difficult to change habits - when asked if the athletes would cut down on snacking with gels and bars to prevent further oral problems, only 17 per cent said they could with ease.
However, more than half (53 per cent) were willing to cut back on sports drinks between meals.
Dr Gallagher said: 'Athletes were willing to consider behaviour changes such as additional fluoride use from mouthwash, more frequent dental visits, and reducing their intake of sports drinks, to improve oral health.
'We subsequently asked some of them and support team members to help us design an oral health intervention study, based on contemporary behaviour change theory and we will publish the results soon.'
The research adds to similar findings from another UCL study published in 2018.
It suggested athletes have an elevated risk of oral disease from a dry mouth during intensive training.
Professor Ian Needleman, who co-led the study, said: 'Nutrition in sports is heavily reliant on frequent carbohydrate intakes, which are known to increase inflammation in the body and gum tissues.
'In sports where there is a lot of airflow, such as cycling and running, breathing hard can make the mouth dry, so teeth lose the protective benefits of saliva.'