Dementia is a devastating condition associated with the ongoing decline of the brain. It currently affects almost one million people in the UK, with this number expected to rise in coming years.

Alzheimer’s disease is the most common type of dementia. While there is no cure for dementia, there are treatments and support available to help people living with the condition.

However, as with any health condition, prevention is always preferable. Research has shown that around 40 percent of dementia cases can be prevented with certain changes, including diet and exercise.

But now a study has found that taking a specific drug meant for something completely different could also do this.

New research, published in the journal Neurology, discovered that taking erectile dysfunction drugs such as Viagra could slash the risk of developing Alzheimer’s disease by nearly a fifth.

As part of the study, researchers followed more than 250,000 men with an average age of 59 who were diagnosed with erectile dysfunction over a period of five years.

The team compared those who were prescribed the drugs with those who were not.

They found that those who were taking erectile dysfunction drugs were 18 percent less likely to develop Alzheimer’s.

This means drugs such as Viagra – which work by dilating blood vessels to allow more blood to flow through – may also help prevent or delay the development of Alzheimer’s disease.

Every participant had been recently diagnosed with erectile dysfunction, and 55 percent had prescription drugs for the condition, while 45 percent did not.

None of the men had problems with thinking or memory – as can be expected in those with Alzheimer’s.

But by the end of the study, 1,119 men had developed Alzheimer’s disease of which 749 were taking erectile dysfunction drugs, corresponding to a rate of 8.1 cases per 10,000 person-years.

Whereas 370 of these were not taking erectile dysfunction drugs, which corresponds to a rate of 9.7 cases per 10,000 person-years.

The “person-years” represent both the number of people in the study and the amount of time each person spent in the study.

Once the researchers adjusted for factors that could affect the rate of Alzheimer’s, such as age, smoking status, and alcohol consumption, they concluded that people who took erectile dysfunction drugs were 18 percent less likely to develop Alzheimer’s.

The association was strongest in those who were issued the most prescriptions over the study period.

Study author Dr Ruth Brauer, from the University College London, said: “Although we’re making progress with the new treatments for Alzheimer’s that work to clear amyloid plaques in the brain for people in the early stages of the disease, we desperately need treatments that can prevent or delay the development of Alzheimer’s disease.

“These results are encouraging and warrant further research, which is needed to confirm these findings, learn more about the potential benefits and mechanisms of these drugs, and look into the optimal dosage.”

She added: “A randomised, controlled trial with both male and female participants is warranted to determine whether these findings would apply to women as well.”

It is not the first time Viagra has been found to have other uses besides tackling erectile dysfunction.

As reported by the Express, a study published in Human Reproduction journal in 2013, found that the little blue pill could also successfully lower pain caused by menstrual cramps and endometriosis.