High Blood Pressure Drugs Help Memory, Study Finds
Our patients often question our primary care doctors in Delray Beach about ways to preserve their memory. The possibility of memory loss can be terrifying and leads people to try anything to keep it intact. This includes buying unproven supplements advertised on television.
Even respected scientists can get caught up in the need for some way to offer hope to patients and their families, as we explained recently. (“Alzheimer’s Drug Approval Brings Controversy”)
But science is still working to find answers to this devastating disease.
High blood pressure and memory
One avenue they’ve explored is the connection between high blood pressure and memory impairment.
In 2016, the National Institutes for Health (NIH) noted several observational studies which seemed to show that high blood pressure in middle age is a risk factor for cognitive decline. This includes overall cognition, memory, and processing speed.
(Cognitive impairment occurs when a person has trouble remembering, learning new things, concentrating, or making decisions that affect their everyday life, according to the Centers for Disease Control and Prevention [CDC].)
One 2019 medical study in the United Kingdom involving 20,000 participants found that people with high diastolic blood pressure were more likely to suffer from cognitive impairment. The study compared participants to people with normal diastolic readings.
The study found that for every 10-point increase in the diastolic reading, the odds of a person having cognitive problems rose by seven percent.
Another federally funded trial found that intensively treating high blood pressure reduced cases of mild cognitive impairment by 19 percent.
Researchers believe the reason is that high blood pressure (hypertension) weakens small arteries in the brain. This results in plaque buildup that can break free, lodge in smaller vessels, and cause damaging clots. If these clots block oxygen from reaching the memory centers in the brain, therefore killing cells there. Ultimately, this begins to impair memory.
This background led researchers to examine whether lowering blood pressure might provide another possible path to better memory in older adults.
As a result, in a study funded by the U.S. National Institute on Aging and the Alzheimer’s Association, researchers found that taking certain types of blood pressure drugs—those known to cross the blood-brain barrier—showed less memory loss over three years than those taking blood pressure drugs that cannot cross that barrier.
“This is one of these situations where it may be that there’s just this other benefit that really is distinct, based on the fact that [the drug] is getting into the brain and hitting those pathways,” study co-author Daniel Nation, said in a statement. Nation is an associate professor of psychological science at the University of California, Irvine.
He also suggested that these particular drugs that are able to cross the blood-brain barrier have some additional benefits in slowing cognitive decline besides reducing hypertension. However, these additional benefits are still unknown.
“I think this effect is independent of blood pressure control,” he said. He also adds that this study did not conclusively prove these drugs lower the risk of dementia.
It’s interesting to note that, although the study focused on the results of blood-brain barrier medications, different positive effects were seen with more traditional drugs.
The study, published last month in the journal of American Heart Association (AHA), Hypertension, reviewed the results of 14 studies. The studies included nearly 12,900 adults ages 50 years and older, from the U.S., Europe, and Japan.
It found that:
- Older adults taking certain blood pressure-lowering drugs that cross the blood-brain barrier had better memory recall for up to three years of follow-up compared to those taking other blood pressure-lowering drugs.
- Adults taking hypertension drugs that did not cross the blood-brain barrier exhibited better attention for up to three years of follow-up.
- There appeared to be no measurable difference with either type of drug in improving such cognitive skills as learning, language, or executive function.
Anti-hypertension drugs that cross the blood-brain barrier are angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors. Other treatments, including calcium channel blockers and diuretics, do not.
ACE inhibitor drugs are:
- Captopril (Capoten)
- Fosinopril (Monopril)
- Lisinopril (Prinivil, Zestril)
- Perindopril (Aceon)
- Ramipril (Altace)
- Trandolalpril (Mavik)
ARB drugs are:
- Telmisartan (Micardis)
- Candesartan (Atacand)
While the results of this latest study show promise, there is still no effective treatment for mild cognitive impairment. Nor is there one for later stages of memory loss including dementia or Alzheimer’s disease.
But it does point us in a general direction.
“The study reminds us that one of the most important things that we can do to reduce the risk of cognitive impairment is to control blood pressure over long periods of time,” Dave Dixon, associate professor, and vice-chair for clinical services at Virginia Commonwealth University’s School of Pharmacy told AARP. Dixon was not involved in the study.
Other effective measures for controlling high blood pressure include changes in diet and exercise, and quitting smoking.
“It seems clear that blood pressure control matters in cognition,” Robert Carey, a professor of medicine at the University of Virginia, told UPI.
If you have questions or concerns about memory loss, be sure to let us know.