Dementia affects 850,000 in the UK, with rates expected to rise to a million by 2025.
There is currently no cure, but new research has found blood-thinning drugs are linked to reduction in dementia risk.
Also known as anticoagulants, they are prescribed to people who have a risk of blood clots, including including those who have recently had surgery or an aortic valve replacement.
The study, published in the European Heart Journal, revealed that patients with the condition atrial fibrillation who took the drugs over a long period had a 48 per cent reduced risk.
Atrial fibrillation is a heart condition that causes an irregular and often abnormally fast heart rate.
The condition can cause blood clots to form, meaning blood-thinning drugs are often prescribed.
It is a common problem in the UK and affects one million people.
In the study, the drugs were also found to reduce risk of stroke in people with atrial fibrillation.
It is the largest piece of research ever to examine the link between anticoagulant treatment and dementia in atrial fibrillation patients.
“We know that what is good for your heart is good for your head,” said James Pickett, Head of Research at Alzheimer’s Society,
“Because of this, many research studies are examining the benefits of treating problems with the blood and heart as a way to potentially prevent or slow down cognitive decline, including some funded by Alzheimer’s Society.
“This large study suggests that anticoagulant drugs could reduce dementia risk in people with atrial fibrillation, but it cannot prove cause and effect.
“For instance, people that seek treatment for medical conditions may be generally healthier than those that don’t or other reasons might be at play.
“If you have atrial fibrillation, make sure you have regular conversations with your doctor about the best treatment options for you.
“Taking good care of your heart in general is thought to be one of the best things to do to do reduce your risk of dementia.
“You can do this by keeping blood pressure in check, eating a healthy, balanced diet an taking regular physical exercise.“