Could a common morning mistake be leading to the cancer that is becoming increasingly common in young people?

Brushing and flossing your teeth regularly may reduce your risk of head and neck cancer, according to promising new research.

Research has long shown that high levels of bacteria associated with gum disease can increase the risk of the condition, as well as diabetes and high blood pressure.

Until now, however, experts did not know which specific bacteria in people’s mouths could be linked to head and neck cancer.

American scientists have discovered more than a dozen species that together increase the risk of squamous cell carcinoma of the head and neck – the most common type – by 50 percent.

According to researchers, their findings highlight the importance of good oral hygiene, which often includes brushing your teeth twice a day, flossing and visiting the dentist regularly.

However, research has shown that only three in ten Britons floss daily.

Study co-author and public health expert at New York University (NYU), Professor Richard Hayes, said: ‘Our results provide another reason to maintain good oral hygiene habits.

‘Brushing your teeth and flossing can not only help prevent gum disease, but may also protect against head and neck cancer.’

Lead study author Soyoung Kwak, a postdoctoral researcher in population health at NYU, added: “Our findings provide new insight into the relationship between the oral microbiome and head and neck cancers.

“These bacteria could serve as biomarkers that experts can use to flag those at high risk.”

In the UK, approximately 12,400 new cases of head and neck cancer are diagnosed each year, and in the US approximately 66,000.

However, according to the NHS, the symptoms can be difficult to spot.

In the UK, head and neck cancer is the eighth most common cancer, accounting for three per cent of all new cases.

There are more than 30 areas in the head and neck where tumors can develop.

According to Macmillan Cancer Support, nine out of 10 head and neck cancers start in squamous cells.

Squamous cells are flat, skin-like cells that cover the lining of the mouth, nose, larynx, thyroid gland, and throat.

Although oral cancer is most commonly diagnosed in older adults, it is also becoming increasingly common in younger people.

Doctors say the human papillomavirus (HPV), a normally harmless virus that is transmitted sexually and through skin contact, could be behind the increase.

In the study, researchers analyzed the diet, lifestyle and medical history data of nearly 160,000 Americans.

Volunteers were asked to rinse their mouths with mouthwash and provide saliva samples. These samples were then stored and tested for the number and types of microbes present.

During a 15-year follow-up, 236 participants were diagnosed with squamous cell carcinoma of the head and neck.

Around 12,400 new cases of cancer are diagnosed in the UK each year, with around 66,000 in the US. But cancer symptoms can be hard to spot, according to the NHS

Their oral microbe DNA was compared with that of 458 participants who had remained cancer-free.

Factors that could influence the results, such as smoking history, age and alcohol consumption, were also taken into account.

Writing in the diary JAMA OncologyAccording to the researchers, 13 species of the hundreds of different bacteria routinely found in the mouth were found to increase or decrease the risk of cancer.

In this group, the chance of developing the disease was 30 percent higher.

When combined with five other types commonly associated with gum disease, the overall risk was increased by 50 percent.

However, they added that the study does not establish a direct link between bacteria and cancer. Instead, it identifies a correlation.

Study co-author and associate director for population research at the Perlmutter Cancer Center said, “Now that we’ve identified the key bacteria that may be contributing to this disease, we want to explore the mechanisms that make this possible and what are the best ways to intervene.”