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Clean Teeth Prevents Heart Disease by 70%

Jun 2, 2010

Individuals who do not brush their teeth twice a day have an increased risk of heart disease, a new study shows. Regular toothbrushing could help stave off cardiovascular disease by 70% according to a nationally-representative study…. 

Individuals who rarely or never brushed were 70% more likely to have a heart attack or other cardiovascular disease event (P<0.001) even after controlling for many other factors, found researchers led by Richard Watt, MSc, PhD, of University College London.


Even brushing once a day rather than twice a day was associated with a significant 30% increase in the risk of these fatal or nonfatal events.

Low-grade inflammation appeared to be playing a role, although whether it is a causal role remains uncertain, Watt’s group reported online in BMJ. These increases in risk could have a “profound public health impact,” they wrote in the study.

Nearly 40% of the population has some degree of periodontal disease, a complex chronic inflammatory condition largely caused by poor oral hygiene, the investigators noted. Its link to cardiovascular disease has been extensively studied with results affirmed and strengthened by the new population-level data.

The researchers used self-reported frequency of tooth brushing as a proxy for periodontal disease, which wouldn’t have been feasible for a large-scale population study, they said.

The analysis included 11,869 men and women ages 35 and older (mean 50) who retained their natural teeth and were without preexisting cardiovascular disease in the 1995, 1998, and 2003 iterations of the Scottish Health Survey of the general population. Overall, their oral health was good. Regular visits to a dentist at least every six months were reported by 62% of respondents and 71% reported brushing twice a day.

Hazard ratio for cardiovascular events (fatal and nonfatal) relative to how often teeth are brushed each day

Frequency of toothbrushing

HR* (95% CI)

Twice a day


Once a day

1.3 (1.0-1.5)

Less than once a day

1.7 (1.3-2.3)

p for trend






More frequent tooth brushing appeared to be dose-dependently protective against cardiovascular disease events — fatal or nonfatal, including cardiovascular disease-related hospitalization, acute MI, coronary artery bypass surgery, percutaneous coronary angioplasty, stroke, and heart failure.

In the analysis adjusted only for age and sex, the risk of a fatal or nonfatal event was 40% greater for those who brushed once rather than twice a day and 2.3-fold higher for those who brushed less than once a day (P=0.001 for trend).

Further adjustment for socioeconomic status, smoking, physical activity, and visits to the dentist attenuated the link. Additional controls for body mass index, family history of cardiovascular disease, hypertension, and physician-diagnosed diabetes also reduced the relationship but not to the point where significance was lost.

For cardiovascular disease-related death alone, similar trends were seen with a 10% elevated risk with once-a-day brushing and 50% elevated risk with less than once-a-day brushing compared with twice daily. However, this relationship lost significance with multivariate adjustment.

The other independent predictors of fatal and nonfatal cardiovascular disease events combined included:

  • Smoking (hazard ratio 2.4, 95% confidence interval 1.9 to 2.9)
  • Hypertension (HR 1.7, 95% CI 1.4 to 2.0)
  • Diabetes (HR 1.9, 95% CI 1.4 to 2.7)

A subgroup of 4,830 study participants gave blood samples from which markers of inflammation (C reactive protein) and coagulation (fibrinogen) were measured. Among them, less frequent tooth brushing appeared to have an effect that remained significant after multiple adjustments (P=0.46 for trend in C reactive protein levels and P=0.015 for trend in fibrinogen levels). Inclusion of inflammatory markers partly attenuated the point estimates for the link between tooth brushing and cardiovascular disease “thus suggesting a possible mediating role,” Watt’s group wrote in BMJ.

They add: “Our study suggests a possible role of poor oral hygiene in the risk of cardiovascular disease via systemic inflammation. Raised inflammatory and homoeostatic responses as well as lipid metabolism disturbance caused by periodontal infection might be possible pathways underlying the observed association between periodontal disease and the increased risk for cardiovascular disease.”Even though the study could not prove that inflammation from poor dental hygiene was causing the increase in cardiovascular events, Watt and colleagues concluded that “educating patients in improving personal oral hygiene is beneficial to their oral health regardless of the relation with systemic disease.”

de Oliveira C, et al “Tooth brushing, inflammation, and risk of cardiovascular disease: Results from Scottish Health Survey” BMJ 2010; 340: c2451 Diabetes Care June.33(6): 1206-12