Scientists have issued a warning as findings suggest that even experiencing a mild bout of Covid-19 could raise your risk of developing Alzheimer’s disease. A new study has found that the virus could alter brain proteins linked to the condition, prompting public health concerns.
The research, published in the journal Nature Medicine, investigated whether both mild and severe cases of severe acute respiratory syndrome coronavirus 2 infection are linked to changes in brain biomarkers associated with Alzheimer’s disease. As part of the study, the team analysed blood samples from 1,252 people from the UK.
Half of these participants had tested positive for Covid, while the other half had not, with some samples taken before the pandemic and others taken after. The controls were matched based on age, sex, ethnicity, and location to minimise confounding factors.
Scientists measured levels of beta-amyloid (Aβ40, Aβ42), pTau-181, NfL, and glial fibrillary acidic protein (GFAP), which are all markers of Alzheimer’s disease.
They also assessed the brain health of participants using neuroimaging data and testing cognitive function.
It was found that those who had COVID-19 displayed significant changes in brain biomarkers associated with Alzheimer’s disease. Covid positive participants had a reduced ratio of Aβ42:Aβ40, which is often linked to Alzheimer’s pathology.
As reported by Medical News, the team found increased levels of pTau-181, a protein associated with tau tangles in the brain, and elevated NfL levels, which indicated neuronal damage in Covid patients. And GFAP, a marker of astrocyte activation and neuroinflammation, was also higher in those who had Covid.
These changes were comparable to four years of ageing or 60% of the effect size of inheriting a single APOE-ε4 allele, a well-known genetic risk factor for Alzheimer’s disease.
It builds on findings from previous studies that suggest that systemic viral infections may increase risks of dementia.
Study authors concluded: “SARS-CoV-2 infection was associated with biomarkers associated with β-amyloid pathology: reduced plasma Aβ42:Aβ40 ratio and, in more vulnerable participants, lower plasma Aβ42 and higher plasma pTau-181. The plasma biomarker changes were greater in participants who had been hospitalized with COVID-19 or had reported hypertension previously.
“We showed that the changes in biomarkers were linked to brain structural imaging patterns associated with Alzheimer’s disease, lower cognitive test scores and poorer overall health evaluations.
“Our data from this post hoc case–control matched study thus provide observational biomarker evidence that SARS-CoV-2 infection can be associated with greater brain β-amyloid pathology in older adults.”
They added: “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.”
This story originally appeared on Express.co.uk
