Last updated at 2:39 AM on 11th September 2008
Keeping your teeth clean could save you from a heart attack, scientists say.
Researchers have found that poor dental hygiene and bleeding gums could allow up to 700 different types of bacteria to enter the bloodstream.
This increases your risk of a heart attack regardless of how fit and healthy you are, they believe.
Gum disease is already known to cause bad breath, bleeding gums and, if untreated, cavities, receding gums and tooth loss.
But experts say the biggest danger to health is the route into the bloodstream for the hundreds of bacteria found in the mouth.
Researcher Professor Howard Jenkinson said: ‘Cardiovascular disease is currently the biggest killer in the western world.
‘Oral bacteria such as Streptococcus gordonii and Streptococcus sanguinis are common infecting agents and we now recognise that bacterial infections are an independent risk factor for heart diseases.
‘In other words it doesn’t matter how fit, slim or healthy you are, you’re adding to your chances of getting heart disease by having bad teeth.’
Details from research into how harmful bacteria interact with blood cells will be released today at the Society for General Microbiology, in Trinity College, Dublin.
A major treatment for heart disease is aggressive antibiotic therapy, but with the rise of drug-resistant bacteria time is running out for this, Professor Jenkinson warned.
The research provides more support for a link between gum disease, heart disease and stroke.
It reproduced the conditions under which bacteria linked to heart disease may end up ‘immune’ from attack by antibiotics, said researcher Dr Steve Kerrigan.
It found the bacteria interacted with platelets – the blood cells which aid blood clotting – in a different way than had previously been thought.
Dr Kerrigan said: ‘Most of the studies that have looked at how bacteria interact with platelets, were carried out under conditions that do not resemble those in the human circulatory system.
‘We mimicked the pressure inside the blood vessels and in the heart.
‘We demonstrated that bacteria use different mechanisms to cause platelets to clump together, allowing them to completely encase the bacteria.
‘This shields the bacteria from the cells of our immune systems, which would normally kill bacteria, – and most importantly also protects them from antibiotics.’
It is not clear how gum disease may trigger heart problems.
But it is thought that bacteria released from the infected gums may increase the rate at which arteries become blocked, say the researchers from Bristol University and the Royal College of Surgeons, in Ireland.
Bacteria entering the bloodstream may activate the immune system, making artery walls inflamed and narrow. Or they may attach directly to fatty deposits already present in the arteries which causes them to narrow further.
Professor Jenkinson added: ‘The mouth is an easy entry for nasty bacteria. Once inside the bloodstream, the platelets, which help the blood clot, latch on to the bacteria.
‘This can cause a blood clot, which can detach and travel to the heart. This is more worrying if the blood clot actually form on the heart’s ventricle.’
The link was proven when scientists found that platelets, which aid repair, attach themselves to harmful bacteria in the mouth, wrongly thinking there is damage to a vein or capillary.