Swedish study links poor oral hygiene with higher cancer risk
Friday, 22 June 2012- Poor oral hygiene may be associated with increased risk of cancer and premature death, researchers found.
Among healthy adults in Sweden plaque build-up increased the relative risk of premature death 79% (OR 1.79 95% CI 1.01 to 3.19, P=0.048), Birgitta Söder, PhD, of the Karolinska Institutet in Huddinge, Sweden, and colleagues reported in BMJ Open.
The finding, the authors wrote, suggests that increased plaque and associated toxins and enzymes, may be released from the built-up biofilm and enter the bloodstream through the gingival crevice, thus increasing the risk of malignancies.
In 1985 Söder and colleagues initiated a longitudinal study of 1,390 randomly selected, healthy Swedish adults ages 30 to 40, who had no signs of periodontitis at baseline. The participants were followed with periodic checkups including smoking habits and oral health through 2009.
Dental plaque measures were taken at baseline and in 1996, 1998, 2000, 2001, and 2009.
Over the 24-year study period, 58 patients died, including 35 deaths due to malignancies.
Individuals still alive at the end of follow-up had a significantly lower dental plaque index than those who died (0.66 versus 0.87, P=0.001).
After multiple logistic regression analysis, Söder and colleagues found age, male gender, as well as the amount of dental plaque were principal independent predictors of mortality at follow-up. Age and male gender almost doubled the risk of dying prematurely -- OR 1.98 (95% CI 1.11 to 3.54, P=0.022) and 1.91 (95% CI 1.05 to 3.46, P=0.034).
They added that there were statistically significant differences between dead and living patients "regarding the amount of dental plaque, gingival inflammation, and dental calculus, indicating a significantly poorer dental status in the subjects who died when compared with survivors."
Söder and co-authors said their hypothesis will require additional studies to determine whether any causal relationship can be derived from the association between poor oral hygiene and cancer mortality.
Source: B. Söder, et al., "The association of dental plaque with cancer mortality in Sweden. A longitudinal study," BMJ Open 2012; 2: e001083; DOI:10.1136/bmjopen-2012-001083.