Research by UCL, which examined medical records of 260,000 men with erectile dysfunction, has provided ‘food for thought’
After a decades-long and largely fruitless hunt for drugs to combat Alzheimer’s disease, an unlikely candidate has raised its head: the erectile dysfunction pill Viagra.
Researchers found that men who were prescribed Viagra and similar medications were 18% less likely to develop the most common form of dementia years later than those who went without the drugs.
The effect was strongest in men with the most prescriptions, with scientists finding a 44% lower risk of Alzheimer’s in those who received 21 to 50 prescriptions of the erectile dysfunction pills over the course of their study.
While the findings are striking, the observational study cannot determine whether Viagra and similar pills protect against Alzheimer’s or whether men who are already less prone to the condition are simply more likely to use the tablets.
I know the blood flow seems obvious, but lesser known is the fact that phosphodiesterase inhibitors have direct impacts on the nervous system. There’s a PDE4 inhibitor that is commonly used in Japan to treat post-stroke inflammation. (Also, caffeine is a weaker, broad spectrum PDE inhibitor.)
"Firstly, PDE5 inhibitors could enhance memory and learning by increasing long-term potentiation mediated by the glutamate NO-cGMP intracellular pathway, as cGMP-activated protein kinase is thought to mediate memory consolidation.
Secondly, as cGMP is a known vasodilator, the cognitive effects of PDE inhibition could be explained by enhanced cerebrovascular function owing to increased delivery of glucose and oxygen to the brain. Finally, improved erections might alleviate performance anxiety and boost self-confidence, with potential benefits to mood, cognition, and general health."
https://www.nature.com/articles/nrurol.2013.309