Will Viagra also cure Alzheimer’s?

Pfizer’s blue pill celebrated its first 25 years a year ago. Approved by the Food and Drug Administration (Fda) in 1998, Viagra has changed the lives of millions of men suffering from impotence and today new benefits are being discovered, such as the possibility that it reduces the risk of developing Alzheimer’s disease.

THE MANY LIVES OF VIAGRA

It was supposed to treat hypertension and angina and, instead, it was accidentally discovered that, although it did not bring benefits with these cardiac pathologies, it had an erection as an unexpected side effect. From here Pfizer decided to study sildenafil, the active ingredient in Viagra, to treat erectile dysfunction, which affects a third of men over 40.

Now this molecule is once again proving useful for something else. According to new research, it could help prevent Alzheimer’s disease.

I STUDY

The study, conducted by scientists at the Cleveland Clinic and published in Journal of Alzheimer’s Diseasefound that people taking sildenafil are significantly less likely to develop Alzheimer’s than similar patients who don’t take it.

The results, however, do not yet prove that the little blue pill is effective against the neurological disorder and, according to researchers, clinical studies are needed to know for sure. However, with the data collected so far it is worth at least attempting a larger and more definitive test.

WHAT THE DATA SAY

The team compared patients taking sildenafil with others taking one of four drugs commonly used to treat pulmonary hypertension. Although the active ingredient is mainly known as an adjuvant for erectile dysfunction, it is also approved and commonly used for this pathology.

The researchers, who had previously conducted studies examining a link between sildenafil and Alzheimer’s, again found that patients taking it were less likely to later be diagnosed with Alzheimer’s than comparison groups, with a reduction in risk including between 30% and 54%.

COMPARISON STUDIES

This data comes after the same team published a paper in 2021 claiming that sildenafil could prevent or delay the onset of Alzheimer’s in older people, possibly reducing the risk by up to 69%. But some researchers had questioned whether the study could actually demonstrate the correlation, and the following year, another study that examined Medicare data found no such link.

Finally, last February, a third group of researchers studied health data from the United Kingdom and found a significant, albeit smaller, reduction in the risk of Alzheimer’s associated with sildenafil.

OTHER TESTS

This time, Cleveland Clinic scientists also conducted other laboratory experiments, testing sildenafil on neurons grown from stem cells of Alzheimer’s patients and found that the drug appears to promote the growth of neurites (the projections that neurons use to communicate with each other) and reduce the accumulation of a potentially toxic form of the tau protein (one of the two proteins believed to be responsible for Alzheimer’s). This is a potential clue as to how sildenafil might actually reduce the risk of Alzheimer’s.