“We can’t be alarmist. This is preliminary data” that needs to be validated by others, said the study leader, Dr. Zoe Arvanitakis of Rush University Medical Center in Chicago. “It’s far too soon to make recommendations about blood pressure in older people based on this study.”
The research began in 1994 and combined people from three studies of aging who agreed to donate their brains for autopsy upon their death, including the Religious Orders Study of Catholic clergy throughout the United States. All were over 65 and without known dementia at the start and were followed until they died — at an average age of 89 and after an average of eight years in the study.
Two-thirds had high blood pressure, defined as a top reading of 140 or more when the study began (it’s now 130 under new guidelines adopted last fall.) Their pressures were measured once a year during the study — a strength of this work over some previous research that just relied on people to say whether they had high pressure or not.
After each participant died, researchers examined their brains for areas of dead tissue caused by lack of blood supply. These blighted areas can be tiny and cause no symptoms, so they’re sometimes called evidence of “silent strokes.”