If you needed another reason to mentally sing two full rounds of 'Happy Birthday' while brushing your teeth tonight, this is probably it.
A team from the Harvard T.H. Chan School of Public Health in Boston have discovered that people with a history of periodontal (gum) disease - which is typically caused by poor brushing and flossing habits that cause a build-up of plaque - appeared to be associated with a raised risk of oesophageal (gullet) cancer and gastric (stomach) cancer.
They examined the association of history of gum disease and tooth loss with the risk of these cancers in more than 98,000 women from the Nurses' Health Study, which ran from 1992 to 2014, and almost 50,000 men from the Health Professionals Follow-up Study, which ran between 1988 and 2016.
The results showed that during 22-28 years of follow-up, there were 199 cases of oesophageal cancer and 238 cases of gastric cancer, and a history of gum disease was associated with a 43 per cent increased risk of oesophageal cancer and a 52 per cent increased risk of gastric cancer.
This risk was also higher among people who had lost teeth. Compared to people with no tooth loss, the risks of oesophageal and gastric cancer for those who lost two or more teeth were 42 per cent and 33 per cent, respectively.
"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," authors wrote in a letter published in the journal Gut about the prospective study.