People with dented smiles run a far greater risk of dying of heart disease than those who still have all their pearly whites, a Swedish researcher said Monday.
"Cardiovascular disease and in particular coronary heart disease is closely related to the number of teeth" that a person has left, Anders Holmlund told AFP, explaining the results of a Swedish study to be published in the Journal of Periodontology.
"A person with fewer than 10 of their own teeth has a seven times higher risk for death by coronary heart disease than a person of the same age and of the same sex with more than 25 teeth left," Holmlund said.
Although many studies published in the past 15 years have showed a link between oral health and cardiovascular disease, Holmlund's study shows a direct relationship between cardiovascular disease and the number of teeth in a person's mouth.
The study, conducted with colleagues Gunnar Holm and Lars Lind, surveyed 7,674 women and men, most suffering from periodontal disease, for an average of 12 years, and examined the cause of death of the 629 people who died during the period.
For 299 of the subjects, the cause of death was cardiovascular disease.
The theory connecting teeth numbers and heart disease, Holmlund explained, maintains that "infections in the mouth and around the teeth can spill over to the systemic circulation system and cause a low graded chronic inflammation," which is known to be a risk factor for heart attacks and other cardiovascular episodes.
The number of natural teeth a person had left "could reflect how much chronic inflammation one has been exposed to in a lifetime," he added.
The study had been limited by the fact that it had not been possible to adjust the results for socio-economic factors and to fully adjust them according to other cardiovascular risk factors, he acknowledged.
Heart disease is the number one killer worldwide, claiming upward of 17 million lives every year according to the World Health Organisation.
Explore further: Tobacco firms get partial win over claims on smoking effects (Update)