Women who have bad teeth or gums—known as periodontal disease—are 14 per cent more likely to suffer from breast cancer, especially if they are past the menopause, say researchers from the American Association for Cancer Research.
The association is stronger in women with periodontal disease who have also been smokers. Those who had quit in the previous 20 years had a 36 per cent higher chance of having breast cancer, although, strangely, the risk dropped to 32 per cent among women who were still smoking.
They based their conclusions on a study of 73,737 post-menopausal women participating in the Women’s Health Initiative, who were followed for nearly seven years, and who didn’t have breast cancer at the start of the study.
The researchers aren’t sure why there’s an association with breast cancer, but they think it’s to do with the bacteria in the gums that eventually makes its way to breast tissue.
Earlier studies have established a link with heart disease, stroke and diabetes, and to oral, esophageal, head, neck, pancreatic and lung cancers.