The long-term research, carried out by Harvard University, found that gum disease – which is caused by plaque build-up – increases the chance of cancer of the oesophageal (mouth) or gastric (stomach) by around 50%.
The scientists from Harvard T.H. Chan School of Public Health followed 98,459 women and 49,685 men for up to 28 years. During that time, there were 199 cases of oesophageal cancer and 238 cases of gastric cancer.
A history of gum disease was associated with a 43% and 52% increased risk of oesophageal cancer and gastric cancer, respectively, the study found.
The risks of oesophageal and gastric cancer were also higher among people who had lost two or more teeth – at 42% and 33% respectively.
Those with a history of gum disease had an 59% increased risk of oesophageal cancer, whether they also had tooth loss or not, compared to those with no history of gum disease or tooth loss.
The study stated: ‘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.’
Gum disease may also lead to heart problems as bacteria spread through the blood, according to the NHS website.