Because there is no treatment for Alzheimer’s, prevention strategies offer the best weapons we have against the disease. And now, researchers are providing a hint of hope with the results of a large, randomized clinical trial: Using intensive measures to drastically lower blood pressure may pay off in the form of dementia prevention for some people.
The study, published today in the journal JAMA, was the culmination of research that started in 2010 to measure how high blood pressure affects other processes in the body. Researchers dubbed it the Sprint Mind study and enrolled over 9,000 people from 102 different places in the U.S. All of them had high blood pressure, with their top number—known as systolic blood pressure in medical terms—falling between 130 and 180. No one had conditions that might predispose them to cognitive impairment, like diabetes or a history of stroke.
The patients were split into two groups: some were treated intensively to lower their blood pressure to 120, while the others received treatment to lower their blood pressure to under 140, which is considered the standard upward range for people under 60. The patients used, on average, two to three drugs to lower their blood pressure to their target range.
The effort worked so well that researchers stopped the trial in 2015. Because the patients receiving the more intense treatment were faring so much better in terms of their cardiovascular health, it was considered unethical to proceed without informing the under-140 group of the benefits.
But researchers continued to track patients for three more years. When they measured who went on to develop mild cognitive impairment, often considered a precursor to Alzheimer’s, they found that the group with a target under 120 had a 19 percent lower risk of being diagnosed with the condition. In the more intensive treatment group, 287 people developed MCI. Comparatively, 353 people were diagnosed in the group with a target in the standard range.
“In the study, we found that just three years of lowering blood pressure not only dramatically helped the heart but also helped the brain,” said the study’s principal investigator, Jeff Williamson, M.D., professor of gerontology and geriatric medicine at Wake Forest School of Medicine.
However, the study was meant to study the effect of blood pressure on dementia—and the results there were not statistically significant. While fewer patients developed dementia in the group targeting 120, the difference was less—176 people in the standard treatment group compared to 149 in the intensive treatment group.
But researchers chalked that up to the fact that dementia develops over several years.
“Dementia takes longer to develop than MCI. Consequently, the early termination of the study likely affected the number of dementia cases detected,” Williamson said. “Further cognitive assessment of the Sprint Mind study participants might discover enough additional cases of probable dementia to support a more definitive conclusion.
Researchers are so buoyed by the results that the Alzheimer’s Association has committed funding for another two years—and effort they’re calling Sprint Mind 2.0.
“Sprint Mind 2.0 and the work leading up to it offers genuine, concrete hope,” said Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer. “MCI is a known risk factor for dementia, and everyone who experiences dementia passes through MCI. When you prevent new cases of MCI, you are preventing new cases of dementia,” she said.
The research findings echo what experts have said for years: What’s good for the heart is good for the head.
“You don’t have to take extreme measures to help lower blood pressure and dementia risk,” said James Pickett, Ph.D., head of research at Alzheimer’s Society. “Simple lifestyle changes like quitting smoking and exercising regularly can all make a difference.”
Without a cure, this kind of research is the best defense older adults have against dementia and cognitive impairment.
“This study is in line with where the field of dementia research is going: preventing memory loss earlier,” said Laurie Ryan, Ph.D., chief of the Dementias of Aging Branch in the NIA Division of Neuroscience. “Much like we have research-based interventions for heart health and cancer prevention, we hope to have guidance based on this and subsequent studies that will more definitively show how to slow or even stop dementia well before symptoms appear.”