Medication to treat high blood pressure may ward off dementia, including Alzheimer's disease, according to report on two studies published in the Archives of Internal Medicine.

A large European study found that medication to treat high blood pressure reduced the risk of dementia by 55 percent. The second study found that the use of antihypertensive drugs was linked with a decrease in the risk of cognitive decline in elderly African Americans.

European researchers conducted a study of 2,902 patients who were taking part in a trial to test the effectiveness of anti-hypertensive drugs on the risk of stroke. Medications used in the study included nitrendipine, with the possible addition of enalapril maleate, hydrochlorothiazide, or both.

The patients were all age 60 or older and were free of any signs of mental decline. A total of 1,485 patients were treated with high blood pressure mediations and 1,417 were given a placebo. After the initial study was over, all patients were permitted to take the high blood pressure drugs and researchers continued to monitor them for mental decline.

More incidences of cognitive decline were found in patients who were taking the placebo. Forty-three placebo patients developed dementia, including 29 with Alzheimer's disease, compared with 21 cases, 12 of which were Alzheimer's disease, in those given high blood pressure medication during the study period.

The second study, conducted by American researchers, followed 1,900 African Americans age 65 and older who, at the start of the study, had no signs of mental decline. Cognitive function was measured at the start of the study and again after two and five years. Prescription and nonprescription medication use was determined from in-home inspection of medications and participant and informant reports.

Of the 1,900 participants, 288 developed cognitive impairment. The use of anti-hypertensive medications reduced the odds of cognitive impairment by 38 percent.

Other sources: Archives of Internal Medicine