How Covid May Affect Your Alzheimer’s Risk

October 5, 2022

Here’s another reason to avoid getting Covid-19: It may increase your Alzheimer’s risk.

People 65 and older who got Covid were up to 80 percent more likely to get a diagnosis of Alzheimer’s disease in the 12 months following Covid disease than their peers who remained unaffected by Covid.

The study showed only a link between Covid and an increased risk of Alzheimer’s disease, and does not prove that the SARS-CoV2 coronavirus that causes Covid-19 plays a direct role in dementia onset. But the findings raise concerns about the long-term potential effects of Covid symptoms on the brain. And earlier studies suggest that a variety of viral infections may cause inflammation in the brain that increases the risk of dementia.

“Since infection with SARS-CoV2 has been associated with central nervous system abnormalities, including inflammation, we wanted to test whether, even in the short term, Covid could lead to increased diagnoses,” she study author Pamela Davis of Case Western Reserve School of Medicine.

For the study, published in the Journal of Alzheimer’s Disease, researchers tracked the medical records of more than 6 million Americans aged 65 and older. About 400,000 of them had a confirmed case of Covid between February 2020 and May 2021.

The researchers found that the risk of developing Alzheimer’s disease in seniors nearly doubled in the year following Covid infection. There were about seven new cases of Alzheimer’s disease for every 1,000 seniors who had Covid, compared to about five new cases among those who had remained Covid-free. The risk was highest in women who were 85 or older. The findings were published in the Journal of Alzheimer’s Disease.

More research is needed to unravel the effects of viral illnesses like Covid on the brain. The underlying causes of Alzheimer’s disease itself remain poorly understood.

“Alzheimer’s disease is a serious and challenging disease, and we thought we had turned some of the tide on it by reducing general risk factors such as hypertension, heart disease, obesity and a sedentary lifestyle,” Dr. Davis said. ““The long-term consequences of Covid are still emerging. It is important to continue to monitor the impact of this disease on future disability.”

Earlier studies have found that people with Alzheimer’s disease are more likely to get Covid, and that having Alzheimer’s disease raises the risk that someone infected with the novel coronavirus will come down with severe Covid and die. Those findings underscore the special importance of vaccination against Covid for anyone with Alzheimer’s disease as well as those who care for them. 

By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University. 

Source: Lindsey Wang, Pamela B. David, Nora D. Volkow, et al: “Association of COVID-19 with New-Onset Alzheimer’s Disease.” Journal of Alzheimer’s Disease, Sept. 13, 2022


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