CHICAGO — Lowering blood pressure more than usually recommended not only helps prevent heart problems, it also cuts the risk of mental decline that often leads to Alzheimer’s disease, a major study finds.
It’s the first time a single step has been clearly shown to help prevent a dreaded condition that has had people trying crossword puzzles, diet supplements and a host of other things in hope of keeping their minds sharp.
In the study, people treated to a top blood pressure reading of 120 instead of 140 were 19 percent less likely to develop mild cognitive impairment. They also had fewer signs of damage on brain scans, and there was a possible trend toward fewer cases of dementia.
“This is a big breakthrough,” said Dr. Jeff Williamson of Wake Forest Baptist Medical Center in North Carolina. “It’s more important than ever to work with your physician to ensure that you have good blood pressure control.”
He led the study and gave results Wednesday at the Alzheimer’s Association International Conference in Chicago. The results are considered preliminary until published, which is expected later this year.
Independent experts cheered the news.
“We have long known that high blood pressure is bad for your heart. Now we’re also learning it’s bad for your brain,” said James Hendrix, director of global science initiatives at the Alzheimer’s Association.
About 50 million people worldwide have dementia, and Alzheimer’s is the most common type. There is no cure — current medicines such as Aricept and Namenda just ease symptoms — so prevention is key.
Roughly half of adults in the United States have high blood pressure under guidelines adopted last year that define it as a top number of 130 or more, rather than 140. Normal is under 120.
High pressure can damage blood vessels and has long been linked to a higher risk for dementia. But it’s not been known if lowering pressure would reduce that risk or by how much. The federally funded study was designed to test this in the most rigorous way.
It involved more than 9,300 people with high pressure. Half got two medicines, on average, to get their top reading below 140. The rest got three drugs, on average, and aimed for 120. During the study, the top pressure averaged 121 in the intensive-treatment group and 135 in the other group.
The study was stopped in 2015, nearly two years early, when it became clear that lower pressure helped prevent heart problems and deaths. But tests of thinking skills continued for two more years, and these new results were revealed Wednesday.
Researchers saw a 19 percent lower risk of mild cognitive impairment in the intensive-treatment group — 285 cases versus 348 in the higher pressure group.
About half of people with mild cognitive impairment develop dementia over the next five years.