Cold acid virus may increase the risk of dementia

According to new research, common viruses that cause cold sores may play an important role in the development of Alzheimer’s disease and dementia.

Herpes simplex virus 1 (HSV-1) affects nearly two-thirds of the global population under 50 years of age and may be more dangerous than previously thought, but antiviral treatments may help reduce risks.

The findings come from a large U.S. study published on May 20 at the BMJ Open, adding to growing evidence that infections may lead to nervous system decline later in life. The researchers analyzed health care data from more than 344,000 patients, making it one of the most comprehensive studies of this link to date.

This discovery is particularly concerned with the widespread HSV-1 infection modes around the world. According to background information in the study protocol, in 2016 alone, an estimated 67% of people under the age of 50 were infected with HSV-1.

Connect with the Virus of Brain Health

The study showed that even after researchers adjusted for other risk factors, people with Alzheimer’s disease were 80% more likely to be diagnosed with HSV-1 than those without.

Over time, can this widespread virus see many of the nuisances that are merely plastic surgery actually damage our brains?

This connection is biologically significant. According to the research team’s protocol, HSV-1 is both “nerve infection and neurotoxicity”, which means it can enter the brain through peripheral nerves and can cause damage. Once inside the brain, the virus may cause inflammation, which leads to the development of Alzheimer’s disease.

“Aβ peptides were reported to be deposited in response to HSV infection and protected host cells by blocking plasma membrane virus fusion, pointing out that HSV is a potential risk factor [Alzheimer’s disease],” the researchers explained in their findings.

Hope to prevent it through antiviral treatment

Perhaps the most promising aspect of this study is that it reveals potential prevention. Of the 2,330 people with HSV-1 infection in the study, 40% received antiviral drugs after diagnosis. The treatment group showed a 17% lower risk of Alzheimer’s disease compared to patients who did not receive antiviral therapy.

“Although the molecular mechanism remains to be fully elucidated, these results suggest that antitoxicological treatments may play a role in mitigating the risk of dementia,” the researchers suggested.

This potential protective effect could have a huge impact on public health strategies, especially given the growing burden of dementia around the world:

• Currently, about 35.6 million people worldwide live in dementia
• About 7.7 million new cases are diagnosed each year
• Alzheimer’s disease accounts for 60-80% of all dementia
• In 2020 alone, it reached $30 billion in the United States alone

Beyond Cold Sores: Other herpes viruses show similar patterns

This study did not stop HSV-1. The researchers also examined other herpes family viruses and found that both HSV-2 (genital herpes) and varicella zoster viruses (which cause varicella and shingles) were associated with an increased risk of Alzheimer’s.

This pattern enhances the situation where viral infections that affect the nervous system can lead to a decline in the nervous system years or decades later.

How Viruses Can Damage to the Brain

Although researchers are still struggling to understand the exact mechanism, several theories have emerged. HSV-1 DNA has been found in characteristic plaques of Alzheimer’s disease. In addition, people carrying APOEε4 gene variants, the most common genetic risk factor for Alzheimer’s disease, appear to be more susceptible to HSV infection.

The brain’s own defense system may inadvertently cause damage. The researchers pointed out that “Aβ has antibacterial properties to various pathogens, including HSV-1.” This suggests that beta-amyloid forms plaques found in the brains of patients with Alzheimer’s disease, which may initially be produced as a defense against viral infections.

Over time, protection can become part of the disease process, especially the recurring viral reactivates over decades.

The way forward: More research is needed

Researchers acknowledge important limitations in their work. Many HSV-1 infections cannot be diagnosed because people have no symptoms or do not seek treatment. The observational nature of the study means that they cannot clearly demonstrate the cause and function.

A systematic review agreement outlines plans for a more comprehensive analysis of existing evidence, with results expected in June 2025. The review aims to examine decades of research to provide clearer conclusions about HSV-1-driven connections.

The researchers concluded that “more emphasis is placed on herpes virus prevention as a public health priority.” By 2050, dementia cases are expected to reach 152.8 million worldwide, so understanding all potential risk factors, especially modifiable risk factors such as viral infections, is becoming increasingly urgent.

For the millions that have used HSV-1, these findings have both attention and hope: While the virus may increase risks, there are already therapeutic options that may help protect the brain. The question now is whether routine antiviral treatments may become part of future strategies for dementia prevention.