Having poor heart health in your 50s could dramatically increase the risk of dementia in old age, research has suggested.
Experts have long warned that well-known cardiovascular risk factors including high blood pressure and cholesterol – not only damage the heart but may also quietly wreak havoc on the tiny, delicate blood vessels supplying the brain.
Now, British scientists have discovered that middle-aged people with damage to their heart muscles were more than a third more likely to develop dementia.
They also found that these biological signals could be evident up to 25 years before a diagnosis.
Researchers today, who labelled the findings ‘important’, urged people to focus on eating well, exercising and not smoking to help keep the heart healthy and reduce dementia risk.
Professor Bryan Williams, chief scientific and medical officer at the British Heart Foundation, which funded the research, said: ‘This study is an important reminder that our heart and brain health are inseparable.
‘The results suggest that middle age is a particularly sensitive time, with damage at this stage setting up a trajectory of decline in heart and brain health.
‘Our advice to focus on heart health throughout life also gives our brains the best chance of ageing well.
Experts today, who labelled the findings ‘important’, urged people to focus on eating well, exercising and not smoking to help keep the heart healthy and reduce dementia risk
‘That means keeping our blood pressure under control, managing our cholesterol levels, staying active, maintaining a healthy weight, and not smoking.’
In the study, scientists led by those at University College London (UCL), examined levels of a protein called troponin in the blood.
This protein is released into the bloodstream when heart muscle is damaged — doctors already look for very high troponin levels in people they suspect of having a heart attack.
If there are higher than normal levels of this protein among people without symptoms, this could indicate ongoing and undetected damage to the heart.
Researchers examined the health records of just under 6,000 people who have worked for the civil service since 1985.
All had a test to examine troponin levels when they were aged between 45 to 69. None had a dementia or heart disease diagnosis when they took the test.
They were then tracked for an average of 25 years and were given tests at six different time periods to assess their memory and thinking skills.
During this period, 695 people were diagnosed with dementia.
Researchers compared each person with dementia to four people without dementia and found that those with the memory condition had ‘consistently’ higher levels of troponin in their blood.
They said this was apparent in blood tests between seven and 25 years before their dementia diagnosis.
Those with the highest troponin levels at the beginning of the study had a 38 per cent higher chance of developing dementia, compared to those with the lowest levels, they found.
Writing in the European Heart Journal, the researchers said that people with increased levels of troponin had a ‘faster decline of cognitive function’.
They also examined MRI scans on 641 people involved in the study and found that people with the highest troponin levels at the beginning of the study tended to have a smaller hippocampus — a region of the brain important for memory some 15 years later.
Professor Eric Brunner, an emeritus professor of epidemiology and health at UCL and study co-author, said: ‘Damage to the brain seen in people with dementia accumulates slowly over the decades before symptoms develop.
‘Control of risk factors common to both heart disease, stroke and dementia in middle age, such as high blood pressure, may slow or even stop development of dementia as well as cardiovascular disease.
‘We now need to carry out studies to investigate how well troponin levels in the blood can predict future dementia risk.
‘Our early results suggest that troponin could become an important component of a risk score to predict future probability of dementia.’
Alzheimer’s Disease is the most common form of dementia and affects 982,000 people in the UK.
Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.
Alzheimer’s Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country’s biggest killer.
However, Alzheimer’s disease is on the rise globally; figures from Frontiers revealed that from 1990 to 2019, new cases of Alzheimer’s and other dementias globally rose by approximately 148 per cent, and total cases increased by around 161 per cent.