Are Covid-19 and herpes viruses silently triggering Alzheimer’s and other brain diseases

Are common viruses including Covid and herpes (HSV-1) silently taking over our brains and triggering degenerative diseases like Alzheimer’s. This stark possibility has been studied by scientists, and findings have been published in the journal ACS Chemical Neuroscience.
According to the study, these viruses can lead to accumulation of protein in the brain which can eventually cause neurodegenerative diseases. Dementia occurs when nerve cells start to lose their function and die which impacts movement, balance, speech, breathing, and heart function.

What are tau proteins

Tau proteins are essential for maintaining the structure of neurons’ axons, which is crucial for effective message transmission between cells. In conditions like Alzheimer’s and frontotemporal dementia, tau proteins become damaged, detach, and form toxic neurofibrillary tangles that harm neurons. This damage disrupts communication in the brain, leading to the cognitive difficulties seen in dementia. Researchers, including Professor Karen Duff at the UK Dementia Research Institute, are working on understanding why tau is damaged and how it causes neuron death, with the goal of developing treatments that protect tau and neurons.

Covid and its effect on brain

According to Harvard Health, Covid can damage the brain in many ways. During the infection, people in some cases may develop encephalitis or inflammation of the brain which can cause confusion, difficulty concentrating, and memory problems. It can also can trigger the onset of new psychological disorders such as severe depression or anxiety. It can even cause people to become psychotic.
Scientists also feel Covid-19 can affect the brain as symptoms like fatigue, persistent headaches, and “brain fog,” are reported which affects memory and concentration. The long-term neurological issues are understood to be the effect of “long Covid.”

“The large and increasing number of people with post-Covid neurological symptoms has renewed the interest in the link between viruses and neurodegenerative brain disorders. There have been similar findings with other post-viral syndromes, including HSV-1 and its link to Alzheimer’s disease,” the researchers wrote.
Another study published in the Journal of Alzheimer’s Disease found that older adults with Covid-19 had a significantly higher risk of developing Alzheimer’s disease within a year of their diagnosis.

How the research was carried out

Researchers took cerebrospinal fluid (CSF) – a clear, protective fluid surrounding the brain from healthy participants and introduced live HSV-1 and ultraviolet-inactivated SARS-CoV-2 viruses in it.
The CSF that was exposed to the viruses triggered clumping together of proteins while the samples which were not exposure to virus showed no such activity.
Many of the proteins identified in these clumps play roles in neurodegenerative diseases and have been detected in amyloid plaques (protein clumps found in the tissue between the nerve cells) from patients.
Amyloid plaques are also linked to other movement-related diseases like kuru and Creutzfeldt-Jakob disease. Researchers believe that viruses may trigger the buildup of harmful proteins, which depletes essential proteins and their functions, potentially contributing to neurodegeneration.
“Understanding the mechanisms by which viruses may cause neurological disorders is especially important due to the SARS-CoV-2 pandemic which has led to a large number of people suffering from long-COVID neurological symptoms post infection,” the experts wrote.