Forgetting to brush your teeth not only leads to stinky breath, there's a good chance it might also lead to heart disease.

That's the finding of a new study that looked at how toothbrushing practices affect the heart. It found that people who don't brush their teeth too often are more at risk of heart disease than counterparts who make it a point to brush twice a day.

The study comes from Scotland and was published this week in the British Medical Journal.

While a lot of research has emerged in the last 20 years noting a link between heart problems and gum disease, this is the first large study to investigate whether dental health specifically relates to heart health.

The study authors, led by Prof. Richard Watt from University College London, analyzed data from&more than 11,000 adults who took part in the Scottish Healthy Survey, which is an ongoing survey offering a detailed picture of the health of the Scottish population.

The authors of this study tracked the volunteers' medical history, family records of disease and lifestyle.

They also looked at blood samples taken from the volunteers. The samples enabled the researchers to determine levels of C reactive protein, which is a biomarker of inflammation in the body, and fibrinogen, a marker of coagulation. The researchers then matched up the data to hospital admissions and deaths until December 2007.

Seven out of 10 of the volunteers reported they brushed their teeth twice a day, and six out of 10 said they visited the dentist every six months.

Those who were less frequent in their brushing, though, had a 70 per cent extra risk of heart disease. They were also likelier to test positive for proteins linked to inflammation, which plays an important role in clogged arteries.

What was remarkable was that the results were unchanged even when other risk factors for heart disease, such as obesity, smoking, socioeconomic status and a family history of the disease were taken into account.

Participants who had poor oral hygiene also tested positive for inflammatory markers such as the C-reactive protein and fibrinogen.

They also found that periodontal disease was associated with a 19 per cent increase in the risk of future cardiovascular disease. Periodontal disease is a chronic infection of the tissue surrounding the teeth, and is caused mostly by poor oral hygiene.

"Our results confirmed and further strengthened the suggested association between oral hygiene and the risk of cardiovascular disease -- furthermore inflammatory markers were significantly associated with a very simple measure of poor oral health behaviour," Prof. Watt said.

How might oral health affect heart health?

Despite the link found, it's still unclear whether poor dental hygiene causes or worsens heart disease or is simply an indicator of risk. Watt said further study would be needed to answer that question.

The idea that gum disease could lead to, or worsen, heart disease has been difficult to prove. Scientists have looked at several ways that the two diseases might be connected.

It's possible that in people with periodontal disease, toothbrushing releases heart-damaging bacteria into the bloodstream. In fact, several species of bacteria that cause periodontal disease have been found in the plaque in arteries in the heart. This plaque can build up, cause atherosclerosis and lead to a heart attack.

A related theory is that when gums swell and become inflamed in periodontal disease, oral bacterial byproducts enter the bloodstream and trigger the liver to release C-reactive protein. That's protein that can then inflame arteries and promote blood clot formation. Studies have found that that the higher the levels of C-reactive protein in one's blood, the higher the risk of having a heart attack.

Another theory is that mouth bacteria harm blood vessels by releasing toxins that resemble proteins found in artery walls. The immune system's response to these toxins could harm vessel walls or make blood clot more easily, possibly leading to strokes.

But these are all theories and no study has yet proven that oral bacteria cause heart attacks, stroke, or premature death. Still, it's well known that not taking care of your teeth will lead to trouble, like cavities, root canals and teeth extractions – all of which can be expensive and painful.

So if you don't want to brush your teeth twice a day for the sake of your heart, do it for the sake of your wallet.