Flossing may be a bore but this kind of fastidious teeth-cleansing might be a lifesaver. Tooth loss increases the risk of a stroke many years later, according to a new Japanese study, and underlying gum disease may be to blame. A stroke is caused by a disturbance of blood supply to the brain. The most common type is an ischemic stroke, which occurs when a blood vessel that normally delivers oxygen and nutrients to the brain is blocked. A haemorrhagic stroke is when a blood vessel bursts, causing bleeding into the brain.
In any stroke the nerve cells in the affected area of the brain may die within minutes of being denied oxygen, leading to impairment of bodily functions. In the new study, researchers at Hiroshima University found that stroke patients in their 50s and 60s had significantly fewer remaining teeth than the patients in the same age groups who had been treated for other conditions.
The number of teeth remaining was also significantly lower among stroke patients in their 50s than in the general population of the same age.
The researchers then analysed and found that having 24 or fewer teeth increased the risk of stroke by 57 per cent compared with those with 25 or more teeth. The researchers also took into account a range of other risk factors associated with stroke, including smoking habits, obesity and alcohol use.
Some studies have suggested a link between periodontal disease and heart disease. Periodontal diseases range from gum inflammation to diseases that damage the tissue and bone that support the teeth. Gum disease is one of the main causes of tooth loss after the age of 40.
The mouth is brimming with bacteria, which contributes to the sticky, colourless plaque that binds to teeth. Brushing and flossing helps get rid of plaque.
One theory is that periodontal disease may cause inflammation in the arteries and brain tissues, which can cause greater amounts of compounds involved in clotting.
It is believed that oral bacteria can contribute to the furring up and narrowing of artery walls, which could result in a stroke. Oral bacteria could also attach to fatty deposits in the arteries, which can lead to a blood clot and result in a stroke.