According to a new study, there may be an association between erectile dysfunction drugs and a reduced risk of Alzheimer’s. Although no clear cause-effect relationship has been identified, erectile drugs (which work by dilating blood vessels) may be a significant ingredient in our fight against the disease.

Alzheimer’s disease, a formidable adversary in the realm of neurodegenerative disorders, continues to challenge scientists and affect millions worldwide. Despite extensive research, the exact cause remains elusive, and there is no direct cure available.

But that doesn’t mean we haven’t learned new things about Alzheimer’s. For instance, researchers are zooming in on amyloid plaques, considered to be one of the hallmarks of the disease. These plaques disrupt neuron function and trigger a cascade of neurodegenerative processes, leading to the cognitive decline and memory loss characteristic of the disease. Many therapeutic strategies aim to reduce their accumulation in the brain as a means to slow or halt the progression of Alzheimer’s.

This is where the erectile dysfunction drugs may come in.

ED and Alzheimer’s

“Although we’re making progress with the new treatments for Alzheimer’s disease that work to clear amyloid plaques in the brain for people with early stages of the disease, we desperately need treatments that can prevent or delay the development of Alzheimer’s disease,” said study author Ruth Brauer, PhD, of the University College London in the United Kingdom. “These results are encouraging and warrant further research.”

Erectile drugs target blood circulation. Specifically, they aim to increase blood flow. But this enhanced blood flow may help in more than one way. It may also have a protective effect on the brain.

To inspect this, Brauer and colleagues followed 269,725 male participants with an average age of 59 who were newly diagnosed with erectile dysfunction over five years. Participants were determined to have no memory or thinking problems at the start of the study. They were then followed for an average of five years. Out of these participants, 55% were prescribed erectile dysfunction drugs and 45% were not.

During the study, 1,119 people developed Alzheimer’s disease. Researchers transformed this into a number of cases per person-years. The people in the erectile dysfunction drug group developed 8.1 cases per 10,000 person-years, whereas the people in the non-drug group developed 9.7 cases per 10,000 person-years.

Even after researchers adjusted for factors that could affect the rate of Alzheimer’s disease (age, smoking status and alcohol consumption), there was still an 18% difference. Furthermore, the association was strongest in the people who were prescribed the most drugs.

An unexpected correlation

Although this is still a preliminary study that only looked at the correlation (not the causation), it’s still pretty suggestive.

“More research is needed to confirm these findings, learn more about the potential benefits and mechanisms of these drugs and look into the optimal dosage,” Brauer said. “A randomized, controlled trial with both male and female participants is warranted to determine whether these findings would apply to women as well.”

This is also far from the first study to suggest a connection between this type of drug and Alzheimer’s. Studies on animals, for instance, have suggested a similar find, as have previous statistical analyses on humans. While the exact pathway remains under investigation, the potential for these medications to influence Alzheimer’s progression is a thrilling prospect.

If further research confirms protective effects of ED medication against Alzheimer’s, it could pave the way for new therapeutic strategies, possibly including the repurposing of these drugs for Alzheimer’s prevention. However, scientists caution that more research is needed to fully understand the relationship and to develop treatment protocols that are safe and effective.

For instance, one limitation of this research was that the study was based on prescription records and did not confirm whether participants actually took the drugs.

The study was published in the medical journal of the American Academy of Neurology.