By Amy Norton
HealthDay reporter
MONDAY, June 21, 2021 (HealthDay News) – Older adults who take certain blood pressure medications may retain more of their memory skills as they age, a new study suggests.
Researchers found its benefit in older people taking drugs that are allowed to cross the “blood-brain barrier,” a border of specialized cells that prevent toxic substances from entering the brain.
These drugs include certain ACE inhibitors and angiotensin II receptor blockers (ARBs) – two main classes of blood pressure medication.
Among nearly 12,900 study patients, those who took the brain-penetrating drugs showed less memory loss over three years than people who took blood pressure drugs that fail to cross the blood-brain barrier.
The results add another layer to the relationship between blood pressure and brain health.
High blood pressure is believed to be a risk factor for dementia, and there is evidence that tight blood pressure controls lower the risk of cognitive impairment – a decrease in memory and thinking skills – with age.
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The new study was published on June 21 in the journal Hypertension.
It suggests that penetrating drugs may have “added benefits” beyond lowering blood pressure, said lead researcher Daniel Nation.
“I think this effect is independent of blood pressure control,” said Nation, associate professor at the Department of Memory and Neurological Disorders at the University of California, Irvine.
Both ACE inhibitors and ARBs act on the body’s renin-angiotensin system, which is essential for regulating blood pressure.
But the brain, Nation stated, has its own renin-angiotensin system that is separate from the body. Research suggests that this system is involved in learning and memory – and that it is “altered” in Alzheimer’s disease.
Nobody denies that lowering blood pressure benefits the brain, Nation emphasized.
A 2018 study called SPRINT-MIND found that “intensive” control of high blood pressure reduced the risk of mild cognitive impairment in older adults by 19% compared to standard blood pressure controls. This meant that the systolic blood pressure (the first number in a reading) was below 120 mm Hg.
“We ask, is there anything we can do beyond aggressive control?” Nation said.
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His team has compiled data from 14 previously published studies in older adults, typically in their 60s or 70s. They were all taking an ACE inhibitor or an ARB for high blood pressure.
Some were taking drugs that cross the blood-brain barrier: the ACE inhibitors captopril, fosinopril, lisinopril, perindopril, ramipril, and trandolapril, or the ARBs telmisartan and candesartan.
Overall, Nation’s team found that patients who received these drugs had slower decline in memory over three years than patients who received non-hypertensive drugs.
Dr. Robert Carey, professor of medicine at the University of Virginia, said the results raise an “extremely important” question about whether certain blood pressure medications are better at slowing memory loss.
This study doesn’t give a definitive answer, he said, but research should continue.
“This is something to look out for,” said Carey, who helped develop the American College of Cardiology / American Heart Association guidelines for the treatment of high blood pressure.
A big question is whether people who take brain-penetrating drugs are ultimately less at risk of dementia.
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“That remains unproven,” said Nation.
And while study patients who received these drugs did modestly better on memory tests, they actually did worse on another cognitive ability: attention.
Nation said this was a surprising finding. But unlike memory, attention can be affected by things like stress and mood.
Carey initially emphasized the importance of controlling high blood pressure “by all means” – including various medications, diet changes, exercise and smoking cessation.
“It seems clear that blood pressure control is important for cognition,” said Carey.
When doctors prescribe high blood pressure medication, they don’t think twice – and probably don’t know – whether the drug is getting into the brain.
But Nation said they could take it into account if an ACE inhibitor or ARB is prescribed anyway.
If patients are already taking an ACE inhibitor or ARB that is not getting into the brain, they may speak to their doctor about switching if they are interested.
The study was funded by the US National Institute on Aging and the Alzheimer’s Association. The researchers report no financial conflicts of interest.
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More information
The American Heart Association does more to control high blood pressure.
SOURCES: Daniel A. Nation, PhD, Associate Professor, Psychology, Department of Memory and Neurological Disorders, University of California, Irvine; Robert M. Carey, MD, Professor, Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, and Vice Chairman, Writing Group, 2017 ACC / AHA Hypertension Guidelines; Hypertension, June 21, 2021, online
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