Drastically lowering blood pressure may help protect memory and thinking skills later in life, researchers reported Monday — the first hopeful sign that it's possible to lower rates of mental decline.
The large blood pressure study looked at more than 9,000 people over the age of 50 years old found that those who lowered their blood pressure to 120 — the top number, or systolic blood pressure — were 19 percent less likely to develop mild cognitive impairment, the loss of memory and brain processing power that usually precedes Alzheimer’s disease. The results of the study, called Systolic Blood Pressure Intervention Trial, or SPRINT, were published in the Journal of the American Medical Association (JAMA).
It has long been known that aggressively lowering blood pressure can benefit those at high risk for heart disease, but this is the first time that the intervention has been shown to also help brain health.
"It offers genuine, concrete hope," said Maria C. Carrillo, chief science officer of the Alzheimer's Association in a statement Monday. "Mild cognitive impairment is a known risk factor for dementia, and everyone who experiences dementia passes through MCI."
Preliminary findings also showed that participants were 17 percent less likely to develop dementia, but the results were not statistically significant because the study was cut short, so a definitive conclusion could not be made.
Because the results have been so promising, the Alzheimer's Association announced that it will award more than $800,000 to support a follow-up trial which will extend follow-up for an additional two years to further investigate the impact of the treatment on reducing risk of dementia.
"The Alzheimer's Association is committed to getting the answers about treating and preventing Alzheimer's and other dementias," said Carrillo.
Earliest form of dementia
High blood pressure is a leading risk factor for heart disease, stroke and kidney failure and a growing body of research suggests it may increase risk for dementia. Last year, U.S. blood pressure guidelines were changed from 140 to 130.
“Whether you are taking BP meds or not, if your BP is above 130 systolic — the top number — you should talk to your doctor about lowering your blood pressure,” said Dr. Jeff Williamson, lead author of the study and gerontologist at Wake Forest School of Medicine in Winston-Salem, North Carolina.
“MCI is simply the earliest form of dementia,” Williamson added. “For anyone whose blood pressure is over 130 or looking to potentially prevent losing memory or thinking skills this is something you can do.”
Alzheimer’s disease is the sixth-leading cause of death in the United States. Nearly 6 million Americans have been diagnosed with Alzheimer’s, including 200,000 under the age of 65. By 2050, experts predict that this number will rise to nearly 14 million, according to the Alzheimer’s association.
There’s no cure, and while there have been indications that a healthy lifestyle can lower the risk, no controlled trial comparing people given a treatment with people not given the treatment has been able to show a reduction in cases of either cognitive decline or dementia.
Still it’s too soon to say that lowering blood pressure can prevent Alzheimer’s and some doctors caution against making blanket changes in patient management based off of these results alone.
“In very old people, we know that lowering blood pressure aggressively may not be good because they have rust in the pipes and they need the pressure,” said Dr. Ronald Petersen, director of the Mayo Clinic Alzheimer's Disease Research Center and the Mayo Clinic Study of Aging, who was not involved in the study.
“What you don’t want people to do is double their blood pressure medicine tomorrow. They need to have a discussion with their primary care physician so they can get their blood pressure down in a controlled way.”