The study found that the brains of men whose hypertension was treated with beta-blockers showed fewer signs of dementia than those of men treated with other blood pressure drugs or none at all.
Experts have called for further research to explore the relationship between beta-blockers, blood pressure and dementia.
Hypertension is a known risk factor for vascular dementia, as well as for strokes and heart attacks.
The 774 male patients in the study were all of Japanese-American ethnicity, and research to establish whether the conditions apply to all ethnicities is needed.
The study found that all types of blood pressure medication reduced the risk of the brain showing post mortem signs of dementia: overall brain shrinkage and tiny areas of brain tissue damage.
However, men who had received beta-blockers showed fewer brain abnormalities than those who had received other blood pressure medications, singly or in combination with beta-blockers.
Study author Dr Lon White said: “These results are exciting, especially since beta-blockers are a common treatment for high blood pressure.”
“This study suggests a link between the use of beta-blockers and fewer signs of dementia, but as the results of this study have yet to be published in full, it’s not clear what caused this link,” noted Dr Simon Ridley, Head of Research at Alzheimer’s Research UK.
“With 820,000 people affected by dementia in the UK, and that number increasing, we urgently need to find ways to prevent the diseases that cause it – that requires a massive investment in research.”