Scientists in London have found that even mild cases of the virus could trigger long-lasting effects on the brain, possibly increasing the risk of the brain-eating disease Alzheimer’s
Tens of millions of Brits who have been struck down with Covid-19 – whether mild or serious – are at an increased risk of developing Alzheimer’s, according to a new study.
Several have already reported horrific long-term symptoms of the virus, known as “long covid”, with brain fog and extreme fatigue being among the most common – lingering for weeks, even months after contracting the illness. But scientists in London have now discovered that even mild cases of Covid-19 could trigger long-lasting effects on the brain, possibly increasing the risk of the brain-eating disease Alzheimer’s.
Their study analysed the health records of 1,200 people and found that those who had tested positive for Covid-19 had more molecules linked to the brain disorder than those who hadn’t. “While these results do not establish causality, they suggest that SARS-CoV-2 (and possibly other systemic inflammatory diseases) may increase the risk of future Alzheimer’s disease,” experts said in the report, published in Nature Medicine.
Alzheimer’s is a progressive brain disease that causes memory loss, confusion, and other symptoms that worsen over time, and is the most common cause of dementia. Roughly 900,000 people in Britain live with dementia, with experts predicted the numbers to rise to one million by the end of the decade.
Viral infections like the flu and herpes, as well as more severe cases of Covid-19, have already been linked to a possible increase in the risk of dementia in former studies. Imperial College London wanted to test whether a mild bout of Covid would have the same impact.
Testing their theory, scientists analysed UK Biobank data and compared the blood, brain scans, and cognitive function of 626 people who had Covid – with 626 who hadn’t. Those who had previously tested positive for the virus displayed lower levels of a key protein ratio related to beta-amyloid buildup in their blood – similar to the effects of four years of ageing – and commonly seen in Alzheimer’s. The group also showed increased proteins linked to brain damage and inflammation.
Findings from the study suggests Covid-19 could speed up brain changes linked to the degenerative condition. The most pronounced changes were seen in older people, and those with health conditions like high blood pressure or obesity. Shockingly, even those with mild or no symptoms from Covid-19 had the same brain changes.
Covid-19 patients overall showed worse brain function, similar to ageing, with some scans displaying patterns seen in Alzheimer’s disease.