Dental Plaque Associated With Early Cancer Deaths

Cancer mortality related to poor dental hygiene study suggests

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Good dental health means brushing your teeth morning and night, flossing once a day and visiting your dentist at least once a year. These guidelines may be particularly important if you've been touched by cancer.

A new observational study, published June 11, 2012 in BMJ Open, suggests that dental plaque may increase the risk of early cancer death by as much as 80 percent.

"Brush and floss your teeth daily - visit your dentist too."

Researchers in Sweden wanted to test whether oral hygiene had an impact on cancer mortality, so they randomly selected and tracked the health of nearly 1,400 people in Stockholm for 24 years - 1985 to 2009.

The participants were all in their 30s and 40s at the beginning of the study. Researchers asked about cancer-related risks, such as smoking. 

Investigators assessed oral hygiene by determining levels of dental plaque, tartar, gum disease and tooth loss the participants had had. Researchers learned that the individuals had high levels of plaque, without apparent signs of gum disease.

By the end of the study, 58 people had died, and 35 of the deaths were cancer-related. The average age at death was 60 for men, who died of a variety of cancers, and 61 for women. One-third of the deaths occurred in women, the majority of whom died of breast cancer.

According to the researchers, these were all considered premature deaths because the women were expected to live about 13 years longer and the men an additional 8.5 years.

Those who died had higher dental plaque index values - .84 to .91 - than those who lived - .66 to .67. This indicates that plaque had covered the gum area of the teeth in the individuals who died. 

Other risk factors were involved. Age nearly doubled the risk of dying from cancer and being male increased the likelihood by 90 percent.

Dental plaque increased the risk of early cancer death by 79 percent.

It should be noted that the absolute risk of premature death was quite low - with only 58 of 1,390 study participants dying within a 24-year period. The authors caution that this study does not prove that dental plaque either contributes to or causes cancer.

“Our study hypothesis was confirmed by the finding that poor [mouth] hygiene, as reflected in the amount of dental plaque, was associated with increased cancer mortality,” they write. “Further studies are required to determine whether there is any causal element in the observed association.”

This research was supported by Ministry of Health and Social Affairs and Karolinska Institutet, Stockholm, Sweden, The Finnish Medical Society, Helsinki, and the Helsinki University Central Hospital, Finland.

No conflicts of interest were disclosed.

Reviewed by: 
Review Date: 
June 11, 2012
Last Updated:
October 1, 2012