Blood pressure medications might lower your risk for Alzheimer's and other types of dementia.
Fighting high blood pressure also fights dementia—and studies hint that successful hypertension treatment may lower a person's risk of memory loss, thinking problems, and even Alzheimer's disease.
"There seems to be a synergistic process in which a person's risk factors for cardiovascular disease work together to decrease cognitive function in general," suggests Dr. Robert Green, associate professor at Harvard Medical School and Brigham and Women's Hospital. Dr. Green studies the genetics of Alzheimer's disease and other neurological conditions.
What the evidence shows
New studies recently published online in the journal Neurology offer intriguing evidence that drug treatments for high blood pressure may go beyond just stroke prevention to include lowering dementia risk across the board. For example:
- A study of 2,197 over-70 men in the Honolulu-Asia Aging Study suggested that after six years, those taking beta blockers (a class of blood pressure drugs) may have had a 31% lower risk of mild cognitive impairment than men not taking beta blockers, even if they were on other blood pressure drugs. No protection was seen in men whose blood pressure remained high despite beta blocker treatment.
- A study of nearly 2,000 normal adults over age 75 in the Ginkgo Evaluation in Memory Study found no protection from ginkgo supplements—but found that those taking any of several classes of blood pressure–lowering drugs had a 42% to 59% lower risk of Alzheimer's disease.
High blood pressure is "not just the No. 1, but also the No. 2 and No. 3 most important risk factor for stroke," notes Dr. Sudha Seshadri, professor of neurology at Boston University School of Medicine. "Stroke, because it takes out part of the brain, doubles the risk of having dementia."
Blood pressure drugs are safe and widely used, so it makes sense to look at them as possible modifiers of dementia progression, Dr. Seshadri says. She is quick to add that these studies do not prove blood pressure drugs have an anti-Alzheimer's effect, and that they don't explain why being on blood pressure medication might prevent or delay dementia.
High BP makes brain vulnerable
The new studies aren't the first to link blood pressure–lowering drugs to decreased dementia risk. Over all, the evidence is contradictory. Some earlier studies found effects for one class of drugs, others found effects for other classes, and some found little or no effect. A recent analysis of these studies was unable to find that any particular medication was better than others at dementia prevention.
"High blood pressure does mean poorer performance in some cognitive domains, but the link to dementia is less clear," Dr. Seshadri says. "Is it that hypertension is bad for your brain, or that being on anti-hypertensive medication is good for your brain? It is hard to separate the two."
Over the course of a lifetime, many people may accumulate small injuries to the blood vessels of the brain that impair brain function. "So you want to minimize all the potential for further injury," he says. "In that context high blood pressure is another risk factor, both at the macro level of stroke and at the micro level of the mental slowness and sluggishness we may experience as we get older."
Dr. Seshadri agrees that there are many factors and many pathways that eventually lead to the breakdown of brain function we call dementia. High blood pressure likely plays a role in this decline.
Overall heart health best
At this point, no one is advising people with normal blood pressure to take antihypertensive drugs to prevent dementia. But the research offers another good reason to make lifestyle changes to reduce or control blood pressure.
"The feeling among neurologists is that hypertension does increase risk of dementia," Dr. Seshadri says. "This is probably true for people who develop high blood pressure in their 30s and 40s, but might also be true for high blood pressure starting later in life, when people are at most risk of dementia."
Hypertension isn't the only heart disease risk factor that contributes to dementia risk.
"Heart health takes a multifactorial approach—lowering cholesterol, watching your blood pressure, eating healthy foods, staying active—and so does brain health," Dr. Seshadri says. "If you can get everything up to speed and fix what is vulnerable, you may keep both your heart and your brain running better."?