Taking newer blood pressure drugs cuts the risk of Alzheimer’s by up to 50 per cent, British scientists say.
Patients on these new drugs are also less likely to develop vascular dementia – a condition caused by problems in blood supply to the brain – than those on older medication.
The first study of its kind opens the door for a treatment that might delay, slow or even prevent dementia.
People with high blood pressure are more at risk of developing Alzheimer’s and similar diseases, but some are protected by the drugs they take, the study shows.
Bristol University researchers investigated medication which targets a biochemical pathway called the renin angiotensin system, thought to affect the onset of Alzheimer’s.
These drugs – known as ARBs and ACE inhibitors – have become increasingly prescribed in the past ten years. They include ramipril, captopril, losartan, candesartan and valsartan.
Scientists analysed data from 40,000 patients aged over 60 who were being treated for hypertension, or high blood pressure.
Alzheimer’s
One quarter had a type of dementia. The biggest benefit was for patients taking ARBs, with a 53 per cent drop in risk, compared with patients on ACE inhibitors, who had a 24 per cent lower risk of Alzheimer’s or similar condition.
This was compared with those taking blood pressure drugs such as beta blockers, calcium channel blockers and diuretics – which have been around longer.
Alzheimer’s patients were half as likely to be given ARBs, according to findings published online in the Journal of Alzheimer’s Disease.
Study co-author Dr Patrick Kehoe, a pharmacologist at the Alzheimer’s Research UK network in Bristol, said it was not possible to determine the minimum period of time needed to benefit from the drugs.
He explained that they block the effects of a hormone called angiotensin II, which results in the destruction of amyloid plaques in the brain that are the hallmark of Alzheimer’s.
The next step is clinical trials to see if the drugs prevent mild cognitive impairment from progressing to full-blown dementia, or delay progression in patients with newly diagnosed Alzheimer’s.
Blood pressure guidelines recommend patients under 55 have ARBs and ACE inhibitors, while older drugs are meant to be more effective in older patients.
Professor Peter Sever, an expert on hypertension at Imperial College London, said the study had ‘very robust findings’.
More than 820,000 people in the UK have dementia.
