Healthy gums, healthy heart?

It is hard to know from de Oliveira and colleagues’ national survey whether lack of toothbrushing causes cardiovascular disease.1 Brushing regularly may reduce the inflammation caused by periodontal disease, or people who do not brush their teeth take less care of themselves in other ways.

Although a 70% increased risk sounds quite large, absolute rates may be more useful in assessing risk. The unadjusted data show:

• •59 people out of 538 (10.9%) who brushed their teeth less than once a day developed cardiovascular disease over about eight years

• •188 people out of 2850 (6.6%) who brushed their teeth once a day developed cardiovascular disease over eight years

• •308 people out of 8481 (3.6%) who brushed their teeth twice a day developed cardiovascular disease over eight years.

This study did not establish a cause and effect relation between oral health and cardiovascular disease. However, in theory these data equate to about 73 cardiovascular events in every 1000 (10.9% minus 3.6%) being prevented by brushing teeth twice a day for eight years instead of brushing less than once a day (unadjusted). Expressed another way, only 14 people would need to do this for eight years to prevent one event (number needed to treat=14). The analysis suggests that these people would probably have other healthy habits.

Good oral hygiene is important in helping to prevent gum disease and tooth decay, regardless of its effect on cardiovascular risk. Equally, following a healthy diet and doing regular physical activity are all important, proved ways to prevent the risk of cardiovascular disease.