Not brushing your teeth increases chance of developing mouth and stomach cancer

Brushing your teeth regularly could cut your risk of developing cancer of the mouth or stomach, according to a study.

Scientists at Harvard T.H. Chan School of Public Health tracked thousands of people for more than 20 years to uncover the link.

They found people with a history of gum disease were up to 52 per cent more likely to develop oesophageal or gastric cancer later in life.

The risk was even higher among people who had previously lost teeth, results also showed.

According to the NHS, the leading cause of gum disease is poor oral hygiene — or not brushing your teeth ‘properly or regularly’.

Research by scientists in Boston found a link between a history of gum disease and developing cancer of the mouth and stomach in later life

Researchers looked at oesophageal and gastric cancer rates in 98,459 women and 49,685 men over at least two decades. 

The results showed that during 22 to 28 years of follow-up, there were 199 cases of oesophageal cancer and 238 cases of gastric cancer.

History of gum disease was associated with a 43 per cent and 52 per cent increased risk of oesophageal cancer and gastric cancer, respectively.

Compared to people with no tooth loss, the risks of oesophageal and gastric cancer for those who lost two or more teeth were also modestly higher.

Participants who lost teeth were an extra 42 per cent more likely to get oesophageal cancer and 33 per cent more at risk of gastric cancer, scientists said. 

A link between bacteria commonly found in the mouth — such as tannerella forsythia and porphyromonas gingivalis — and oesophageal cancer has been made by other scientists in previous studies.

Another possible reason is that poor oral hygiene and gum disease may promote the formation of bacteria known to cause gastric cancer, scientists said.

Other findings on the relationship of gum disease and tooth loss with oesophageal and gastric cancer have been inconsistent, the authors said. 

The authors concluded: ‘Together, these data support the importance of oral microbiome in oesophageal and gastric cancer.

‘Further prospective studies that directly assess oral microbiome are warranted to identify specific oral bacteria responsible for this relationship.

‘The additional findings may serve as readily accessible, non-invasive biomarkers and help identify individuals at high risk for these cancers.’

It comes after US researchers last year claimed having gum disease could raise your risk of getting Alzheimer’s in later life.

Scientists led by the company Coretxyme found for the first time that bacteria which cause bleeding gums can get from the mouth into the brain.

Signs of this gum disease bacteria were found in the brains of 51 out of 53 people with Alzheimer’s disease.

The findings suggested that people who brush their teeth properly could lower their risk of dementia.

However, it raises concerns for the 45 per cent of people in Britain who already have gum disease and may be at greater risk.