By the time you reach what is commonly called middle age, you’ll likely notice awkward moments when you suddenly can’t remember a simple word, your best friend’s name, the movie you saw last night or even what you planned to say next. These embarrassing slices of silence are often referred to as “senior moments,” which insinuates they are the result of an aging brain. However, the inability to recall simple information may be due to another factor—sudden surges in blood pressure.
Researchers led by Jason C. Allaire, PhD, an assistant professor of psychology at North Carolina State University in Raleigh, studied 36 women and men between the ages of 60 and 87. While monitoring the participants’ ongoing blood pressures, the researchers had the group complete a series of cognitive-function tests every morning and evening for 60 consecutive days. The tests were designed to assess problem solving and thinking abilities as well as pattern recognition.
The participants with an average systolic blood pressure of 130 or higher tended to perform poorly in the cognitive tests; in particular, the inductive reasoning task where participants were asked to identify a pattern in a series of letters and predict the next letter in the series. The higher the blood pressure, the more mistakes the participants made. However, there was no change in cognitive functioning among those whose average blood pressure was in the low or normal range, even when their blood pressure rose above normal. “If you have high blood pressure, on days when your blood pressure spikes higher than normal cognitive ability is worse than normal,” concluded Allaire.
Previous studies have shown that elderly people with high blood pressure have poorer mental skills than those with normal blood pressure, but none of those studies evaluated the impact of surges in blood pressure. However, it remains unclear whether it is high blood pressure itself or the stress of struggling with a mental task that causes the blood pressure to rise that is responsible for the decline in cognitive functioning. “The question is: is it the increased blood pressure or is it the stress? And the answer is: it could be both,” Allaire said.
Regardless, the findings offer yet another reason for people to keep their blood pressure under control. “This finding suggests that if you have high blood pressure that is not controlled, your cognitive abilities are going to decline faster as you get older,” Allaire said. “If you have blood pressure that wildly fluctuates and you have high blood pressure, you might be in double trouble for poorer cognitive functioning.”
High blood pressure is a major risk factor for heart disease and stroke, both leading causes of death in the United States. According to estimates by the Centers for Disease Control and Prevention, about 1 in 3 American adults have high blood pressure, and among those, almost one-third don’t even know they have it. High blood pressure for adults is defined as a systolic pressure (while the heart is beating) of 140 mmHg or higher, or a diastolic pressure (when the heart is resting between beats) of 90 mmHg or higher. Normal blood pressure is a systolic blood pressure less than 120 and a diastolic blood pressure less than 80.