Patients who took a certain type of blood pressure medication got measurable relief from worsening Alzheimer's symptoms, too, researchers reported on Thursday.
It's the latest in a series of studies on the effects of various blood pressure drugs on the fatal and incurable brain disease, which is affecting more and more Americans as people live longer.
In this case, it was a type of drug called an ACE inhibitor. Patients at a hospital in Ireland who were taking the drugs anyway to treat their high blood pressure did not worsen at the same rate as patients not taking the drugs, said William Molloy of the Centre for Gerontology and Rehabilitation at University College Cork in Ireland.
"They were not progressing at the same pace as other people," Molloy told NBC News.
Molloy, who treats Alzheimer's patients, said he decided to look after he saw other studies suggesting ACE inhibitors might help. He went back through the medical records of 800 patients with Alzheimer's or vascular dementia. Of them, 360 had test scores the team could use to assess the progress of their disease over six months.
Those taking the ACE inhibitors lost their memory and other thinking abilities at a rate that was about 20 to 30 percent slower than the others, Molloy's team reported in a study published Thursday in BMJ Open.
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"That may not sound like very much," he said. But over years, the effect would be compounded. And these drugs are available generically and very cheap.
The results would have to be tested in a larger study—preferably a so-called double-blind, prospective study that looked at patients over time, with the drug randomly assigned. That's important because doctors may have prescribed the drugs to patients for reasons that could also affect the course of their disease, said Dr. Gary Small of the David Geffen School of Medicine at the University of California, Los Angeles and director of the UCLA Longevity Center.
"The doctors decide who goes on the drug and who doesn't. It might be some other factor that is driving the improvement," said Small, who was not involved in the study.
Alzheimer's is a huge and growing problem. Researchers project that the number of Americans living with Alzheimer's will triple in the next 40 years, which means that 13.8 million will have it by 2050.
Census data project that as the baby boom generation ages, the number of Americans aged 65 to 84 will approximately double by 2050. Currently an estimated 4.7 million Americans have Alzheimer's, the most common cause of dementia.