Frequent Antacid Use by Elderly Black Patients Increases Risk for Developing Dementia, Study Finds
Elderly blacks who frequently take antacids to relieve heartburn and indigestion have a higher risk of developing dementia than those who are not frequent users, according to a study published in the Journal of the Geriatrics Society, the Los Angeles Times reports. Antacids, also known as histamine-2 receptors or H2As, work by blocking the production of stomach acid, but they also inhibit the brain's cholinergic system, which is involved in memory and cognition. Low levels of cholinergic activity previously have been linked to dementia, according to the Times.
The study -- led by Malaz Boustani, a geriatrician at the Indiana University School of Medicine -- examined 1,558 elderly black Indianapolis residents. Researchers surveyed participants for use of antacids and other medications. None of the participants had dementia at the start of the study (Maugh, Los Angeles Times, 8/4). During follow-up examinations, 275 subjects, or 17.7% of participants, showed signs of diminished cognitive capacity, according to the study. After taking into account age -- participants were 65 and older -- education level and medical history, researchers found that treatment with H2As more than doubled the likelihood of developing cognitive impairment (Reuters, 8/6). According to the Times, the study did not look at other races besides blacks, and it did not find enough data to suggest an increased risk of dementia from taking proton pump inhibitors, another class of acid-inhibiting drugs (Los Angeles Times, 8/4).
Researchers said the study "suggests that long-term use of H2As is associated with cognitive impairment in elderly African-Americans. Because a significant number of Americans are exposed to H2As every year, with approximately 16 million prescriptions in 2005, the association between H2As and cognitive impairment merits further study" (Reuters, 8/6). Boustani said, "This is a very limited study in a specific population, but it picked up a signal that really needs to be confirmed. The picture is really not clear yet." He added that he is not ready to suggest that people stop taking antacids.
John Morris of Washington University in St. Louis, who was not involved in the study, said, "This is certainly not the final word on the potential risk of these drugs. But what it tells us is that, for older adults, drug use should be considered very carefully" (Los Angeles Times, 8/4).
An abstract of the study is available online.