Using mouthwash daily could raise your risk of diabetes

Using mouthwash twice a day significantly raises the risk of obesity and developing type 2 diabetes, according to a new study. 

US researchers claim that swilling with the anti-bacterial fluid could be killing beneficial microbes which live in the mouth and protect against the conditions.

People who used the product twice a day were around 55 percent more likely to develop diabetes or dangerous blood sugar spikes – known as prediabetes – within three years.  

This is the first research to show that the seemingly positive practice designed to boost your oral health can have unhealthy consequences.

Nearly all popular mouthwash solutions include ingredients that kill bacteria – both the good and bad, explained the study authors from Harvard School of Public Health.

Mouthwash may kill off helpful microbes in the mouth which protect against diabetes and obesity, found the Harvard School of Public Health (stock image)

Joshipura, Professor of epidemiology at the Harvard School of Public Health said: ‘Most of these antibacterial ingredients in mouthwash are not selective.

‘In other words, they do not target specific oral bacteria-instead, these ingredients can act on a broad range of bacteria.’

It is estimated that 415 million people are living with diabetes in the world, which is estimated to be 1 in 11 of the world’s adult population.

How the research was carried out


The main function of most mouthwashes is to freshen breath.

Some types, such as fluoride rinses, can help protect teeth against acids produced by plaque bacteria if you use them after you have thoroughly brushed your teeth.

The first commercial product was developed in the late 19th century and named Listerine, after British surgeon Joseph Lister.

It was originally intended as a surgical antiseptic, but by the 1920s was sold as a cure for bad breath as well as a dandruff remedy and floor cleaner.

According to the British Dental Association, daily mouthwash use is not necessary to oral healthcare and warns it does not ensure plaque and food build-up are removed. 

The team looked at 1,206 overweight people aged 40 to 65 who were deemed at risk of developing diabetes.

Over the study period, around 17 per cent of developed diabetes or pre-diabetes, but that rose to 20 per cent for those using mouthwash once a day, and 30 per cent for those using it in the morning and evening. 

Helpful bacteria in the mouth can protect against obesity and diabetes, as it helps the body produce nitric oxide.

This important molecule helps trillions of our cells to communicate with each other by transmitting signals throughout the entire body and regulates insulin levels and our metabolism.  

Commonly-used mouthwashes typically contain powerful bacteria-killing formulas including cetylpyridinium chloride, chlorhexidine, triclosan, alcohol, fluoride, peroxide and essential oils.

However, the researchers warn killing off good helpful bacteria also makes room for harmful bacteria to thrive. Therefore, they said that rinsing once a day may be advisable.