How an irregular heartbeat raises your risk of dementia
But the good news is that sufferers who are given blood thinners to avoid the risk of clots caused by the heart problem end up having a lower risk of Alzheimer’s and similar brain diseases.
The irregular heartbeat in question is atrial fibrillation (AF).
The heart’s normal rhythm is out of sync and as a result, blood may pool in the heart, possibly forming clots which cause a stroke.
The study found that sufferers may experience a faster decline in thinking and memory skills and have a greater risk of dementia than those without the condition.
But those AF sufferers who take anticoagulants such as warfarin were protected, the research by the Karolinska Institute and Stockholm University in Sweden found.
Study author Dr Chengxuan Qiu said: “Compromised blood flow caused by AF may affect the brain in a number of ways.
“We know as people age, the chance of developing atrial fibrillation increases, as does the chance of developing dementia.
“Our research showed a clear link between the two and found that taking blood thinners may actually decrease the risk of dementia.”
Last night, research bodies in the UK welcomed the new paper.
Dr James Pickett, head of research at Alzheimer’s Society, said: “It is well established that what is good for your heart is good for your head and this research adds even more weight to the relationship between heart health, stroke and vascular dementia risk.
“This highlights the need to explore every avenue to help us unearth more vital information on what is now the UK’s biggest killer.
“This is why we’re funding over £2.5million of research specifically into the relationship between the heart and dementia.”
For the study, published online by the journal Neurology, researchers followed 2,685 participants with an average age of 73. Participants were examined and interviewed at the beginning, then once after six years for those younger than 78 and once every three years for those older.
All were free of dementia at the start of the study, but 243 people – nine per cent – had AF.
Researchers found that those who had AF were 40 per cent more likely to develop dementia over the time period. But those who took blood thinners for the heart condition had a 60 per cent decreased risk.
Of the 128 people taking blood thinners, only 14 developed dementia compared to 76 of the 342 people who did not use them. Dr Qiu explained: “Assuming that there was a cause-and-effect relationship between using blood thinners and the reduced risk of dementia, we estimated that about 54 per cent of the dementia cases would have been hypothetically prevented if all of the people with AF had been taking blood thinners.
“Additional efforts should be made to increase the use of blood thinners among older people with AF.”