Viagra could be used to stop the onset of dementia, scientists believe.
A trial has been launched to see if the drug – normally used to treat erectile problems in men – could help stave off a common form of the disease.
The drug, called Tadalfil – which is in the same family as Viagra – works by dilating blood vessels.
Scientists believe it could treat vascular dementia by increasing blood flow to the brain.
Vascular dementia is the second most common form of dementia, and accounts for around 110,000 cases of dementia in the UK.
It is caused by damage to the small blood vessels of the brain, leading to reduced blood flow to brain tissue.
This damage to the brain’s blood vessels – known as small vessel disease – makes artery walls become thick and stiff, which prevents them from responding to the brain’s changing need for blood.
The result is damage to deep parts of the brain due to insufficient blood supply, leading to problems with memory.
The damage, which can develop and progress over many years, is seen in the brains of 50-70 per cent of older people.
The researchers hope Tadalafil’s blood-flow boosting properties can prevent this damage, and stave off vascular dementia.
Dementia, characterised by deterioration in memory, thinking, behaviour and the ability to perform everyday activities.
Worldwide, 35.6 million people have dementia and there are 7.7 million new cases every year, according to World Health Organization figures.