Treating High Blood Pressure May Slow Cognitive Decline
- Researchers say high blood pressure in older adults can quicken the onset of cognitive decline.
- Treating hypertension may slow the progress of this decline.
- High blood pressure can harden the walls of the arteries in the brain and cause microbleeds.
New research suggests there’s even more reasons for middle-aged and older adults to keep a close watch on their blood pressure.
Besides higher risk of stroke, heart attack, and other illnesses, research presented at the American Heart Association’s (AHA) Hypertension 2019 Scientific Sessions adds to the growing body of evidence that high blood pressure (hypertension) can also affect a person’s mind as they age.
It also suggests that treating the condition can help stave off cognitive decline.
The AHA estimates that more than 100 million adults in the United States have high blood pressure. That’s almost half the adult population in the country.
That’s why the organization says researching how the condition affects the brain’s blood vessels is important.
In the recent study, researchers at Columbia University in New York City analyzed data collected from nearly 11,000 adults enrolled in the China Health and Retirement Longitudinal Study (CHARLS).
They were looking to find out if high blood pressure — and whether the person with it was treating it — affects a person’s memory, language, and thinking skills.
Chinese researchers interviewed people involved in the study in their homes about their high blood pressure, using a blood pressure threshold of 140/90 mm Hg. The AHA notes their guidelines for hypertension are lower at 130/80 mm Hg.
The researchers also asked study participants how they were treating their condition. In addition, they asked the participants to take tests that scored their cognitive abilities, such as recalling words as part of a memory quiz.
The study was observational, which means researchers relied on what people told them, not medical records and other less-subjective measures. It also didn’t examine if some treatments were more successful than others.
But researchers say they did notice that people over age 55 with high blood pressure lost their mental abilities more quickly than those who didn’t.
They also reported that people who were treating their condition had the same rate of cognitive decline as those without high blood pressure.
“We think efforts should be made to expand high blood pressure screenings, especially for at-risk populations, because so many people are not aware that they have high blood pressure that should be treated,” Shumin Rui, a study author, graduate of Columbia University, and an associate biostatistician at IQVIA consultants, said in a press release.
Rui also said while the study focused on middle-aged and older adults in China, the results could apply to populations elsewhere.
“We need to better understand how high blood pressure treatments may protect against cognitive decline and look at how high blood pressure and cognitive decline are occurring together,” she said.
The importance of the research
Jagdish Khubchandani, PhD, associate chair and professor of health science at Ball State University in Indiana, said an exciting part of the research is that it could be the first study regarding high blood pressure and cognitive decline in the Chinese population.
He said it means earlier findings from Western countries hold true across different populations where diet, lifestyle, environment, and social circumstances can widely vary.
“With this new study and somewhat known findings, there’s more proof that high blood pressure may accelerate the process of age-related cognitive decline, especially if left untreated,” Dr. Khubchandani told Healthline.
Other experts say the research does add some interesting perspective to what’s been known for quite some time: There’s a connection between high blood pressure and cognitive decline in older people.
Part of that could be how hypertension hardens the walls of the arteries, creates microbleeds in the brain, or decreases blood flow to important brain tissue that, over time, could slowly build to larger problems.
It’s also part of the reason it’s one of the first tests performed when you visit your doctor’s office or walk in through the doors of an emergency room.
What’s the connection?
Stephen Sidney, MD, a senior researcher at the Kaiser Permanente Division of Research in Northern California, said high blood pressure is considered a risk factor for cognitive impairment and dementia.
It’s also one of many factors that contribute to hardening of the arteries that provide oxygen supply to the brain.
“It takes many years and even decades for this to occur to the point where oxygen supply to the brain is compromised,” Dr. Sidney told Healthline.
Meanwhile, at Kaiser Permanente in Southern California, Columbus Batiste, MD, a cardiologist, said medical professionals have known for years that there’s a relationship between elevated blood pressure and cognitive decline among people ages 40 to 60.
He said research has shown for every 10-unit increase in systolic blood pressure — the top number in the measurement — there’s a 9 percent decline in cognitive function.
One such study — Atherosclerosis Risk in Communities — has shown hypertension and prehypertension in middle-age is associated with cognitive decline, and people who didn’t treat their high blood pressure were at greater risk for it.
Dr. Batiste said one of the underlying causes could be when the walls of the arteries harden, potentially leading to small brain hemorrhages (microbleeds).
“Microbleeds are frequently found with people with high blood pressure, even if one is not diagnosed with a stroke,” he said. “These microbleeds have been proposed as a cause of cognitive impairments.”
They’re also associated with brain tissue death and small strokes that often don’t have symptoms as they occur, but can contribute to cognitive impairment.
All are good reasons for people to treat their high blood pressure.
Ways to treat high blood pressure
Batiste said the first step in treating high blood pressure is “knowing your numbers,” as they provide insight into a person’s risk factors for not only cognitive impairment but also for heart failure, heart attack, stroke, and kidney failure.
The second step is working with your medical care team to start “aggressive lifestyle intervention,” he said.
That can include daily exercise as well as a diet based on eating berries, green leafy vegetables, and legumes while eliminating processed and packaged foods that are high in sodium.
Other interventions may include relaxation exercises to combat stress, getting more sleep, and screening for sleep apnea.
“If lifestyle measures aren’t effective, it’s important to talk with your doctor again to consider medications, being sure to communicate if any concerns arise because there’s no one-size-fits-all approach,” Batiste said.