To study whether alcohol consumption is associated with the risk of dementia and cognitive decline in older adults with and without MCI, the investigators analyzed data from the Ginkgo Evaluation of Memory Study (GEMS). GEMS was a randomized controlled trial conducted between 2000 and 2008 that found no overall association between ginkgo biloba and dementia prevention. During the trial, participants completed the Modified Mini-Mental State Examination, the Clinical Dementia Rating scale, and the cognitive portion of the Alzheimer’s Disease Assessment Scale.
In the present study, the investigators analyzed data from 3,021 participants aged 72 years and older who were free of dementia at baseline and had provided information about their alcohol intake. Their median age was 78 years, and 46.2% were female. Fifty-eight percent consumed alcohol, including 45% of the participants with MCI at baseline.
During follow-up, 512 cases of dementia occurred. Among the 473 participants with MCI at baseline, the adjusted hazard ratio (HR) for dementia was 1.72 for those who consumed more than 14 drinks per week, compared with light drinkers who consumed less than 1 drink per week. For participants who consumed between 7 and 14 drinks per week, the adjusted HR for dementia was 0.63 among those without MCI and 0.93 among those with MCI, relative to light drinkers who consumed less than 1 drink per week.
Among adults with normal cognition at baseline, daily low-quantity drinking was associated with lower dementia risk, compared with infrequent higher-quantity drinking (HR, 0.45).
Trial excluded adults with excessive alcohol use
Limitations of the study include a lack of data about any changes in alcohol consumption over time. In addition, the original trial excluded people with a known history of excessive alcohol use. Furthermore, it is possible that the “long preclinical phase of dementia” and other health issues affect drinking behavior, the authors said. “At present, our findings cannot be directly translated into clinical recommendations,” the authors said. Nevertheless, the results “suggest that, while caring for older adults, physicians should carefully assess the full dimensions of drinking behavior and cognition when providing guidance to patients about alcohol consumption,” they said.
The study was supported by grants from the National Center for Complementary and Alternative Medicine; the National Institute of Neurological Disorders and Stroke; the Office of Dietary Supplements of the National Institute on Aging; the National Heart, Lung, and Blood Institute; the University of Pittsburgh Alzheimer’s Disease Research Center; the Roena Kulynych Center for Memory and Cognition Research; and Wake Forest University School of Medicine. In addition, the researchers used plasma samples from the National Cell Repository for Alzheimer’s Disease, which receives support from the National Institute on Aging. Dr. Koch had no conflicts of interest. Coauthors disclosed university and government grants and personal fees from pharmaceutical companies outside the study. One author was an employee of Genentech at the time of publication, but Genentech did not contribute to the study.
SOURCE: Koch M et al. JAMA Network Open. 2019 Sep 27. doi: 10.1001/jamanetworkopen.2019.10319.