Effects of dementia slowed by ACE inhibitors, research suggests

Blood pressure lowering drugs have the potential to slow the rate of cognitive decline, according to new research from Ireland and Canada. 

Researchers from University College Cork and McMaster University in Ottawa, Canada, compared the rates of cognitive decline in 361 patients of an average age of 77 with Alzheimer's disease and/or vascular dementia and found that ACE inhibitors marginally slowed cognitive decline.

ACE inhibitors target a specific biochemical pathway called the renin angiotensin system – a hormone system that is thought to affect the development of Alzheimer’s disease. 

The researchers also assessed the impact of the inhibitors on the brain power of 30 patients newly prescribed these drugs, during their first six months of treatment. They found that their brain power improved over the period, compared with those already taking them, and those not taking them at all.

Dr James Pickett, head of research at the Alzheimer's Society, said: "We've known for some time that high blood pressure increases your risk of developing dementia. Any drug which halts cognitive decline is potentially exciting – as it has the ability to radically improve people with dementia's quality of life. The more we learn about dementia and how it relates to other conditions like high blood pressure, the more we’re able to explore whether existing drugs such as these can double as dementia treatments. 

Dr Pickett did warn that people should not start taking any drugs that they have not been prescribed.

He added: "People should speak to their GP before taking any [unprescribed] drugs. One in three people over 65 will develop dementia. We need much more research into potential treatments to enable people to live well with the condition." 

Those with high blood pressure are more at risk of developing Alzheimer’s and similar diseases, but this is the first study to find that people's memory and thinking skills could be protected by the drugs.

Significant clinical benefits  

ACE inhibitors – whose names include ramipril, captopril and perindopril – have become increasingly popular in the past 10 years, particularly for younger patients.

The results of the test, which measured participants cognitive decline using the Standardised Mini Mental State Examination and the Quick Mild Cognitive Impairment tests, were published in the journal BMJ Open. 

The researchers concluded: "Although the differences were small and of uncertain clinical significance, if sustained over years, compounding effects may well have significant clinical benefits."