Alzheimer’s more common among older people who had Covid-19, study finds

A new study suggests that Covid-19 may improve the risk of Alzheimer’s in older people.

The research, published in the Journal of Alzheimer’s Disease, analysed over six million adults aged 65 or older with no prior Alzheimer’s disease diagnosis.

The study does not show that Covid-19 causes Alzheimer’s, but it adds to the growing body of research drawing links between coronavirus infection and cognitive function.

Dr. David Holtzman, a neurologist from the Washington University School of Medicine, said: “In the Alzheimer’s disease brain, the pathology starts to build up about 20 years before the symptoms begin.

“The brain has its own immune response to the pathology that’s involved in [Alzheimer’s] disease progressing.

“When there are other things that cause inflammation that are in the body that can affect the brain, likely what happens is that can even amplify the process that’s already going on.”

The study authors identified this work as a call for more research on the underlying mechanisms of Alzheimer’s disease that might explain the association.

Dr. Eliezer Masliah, director of the division of neuroscience at the National Institutes of Health’s National Institute on Aging, said: “In the next couple of years, we’re going to have a lot of very important information.

“Imagine how many millions of people over the age of 60 or 65, like myself, have had Covid. Say five per cent of them or ten per cent of them or even one per cent of them are at risk.

“We’re looking at a lot of people in the next few years that might add to the already very large epidemic of Alzheimer’s disease that we have.”

The limitations of the study include the retrospective and observational nature of the study that could introduce potential biases and Alzheimer’s disease diagnosis inaccuracy, which may not have affected the relative risk analyses considerably since both groups were formed from the same dataset.