Medications used to combat high blood pressure appear to be linked to a lower incidence of Alzheimer’s disease, according to a study published on Monday.

Whether there is a true cause-and-effect relationship needs further study, said the report from Maryland-based Khachaturian and Associates.

The study looked at 3,297 elderly residents of Cache County, Utah, who were examined between 1995 and 1997, and later given follow-up examinations beginning in 1998.

While all hypertension medications in the study seem to have an impact, the greatest reduction in the risk of Alzheimer’s disease was found in those taking diuretics, which cause the kidneys to excrete water and salt but spare the elimination of potassium.

Unpublished findings from another study “suggest that increased potassium levels may be associated with a reduced risk of dementia,” said the study, while other researchers have found that low potassium concentrations are associated with changes in the brain that may lead to Alzheimer’s disease.

While high blood pressure is thought to raise the risk of Alzheimer’s, “the protective effects of these antihypertensive medications may be independent of their ability to control blood pressure,” the study said.

About one in three American adults suffers from high blood pressure.

The study was published in the Archives of Neurology.