Researchers have discovered a surprising potential link between herpes infections and dementia, raising questions about how early-life infections might affect brain health as we grow older.

A study conducted by Uppsala University in Sweden suggests that people infected with herpes could be at a higher risk of developing dementia later in life.

Herpes simplex virus type 1 (HSV-1), which causes oral herpes or cold sores, is incredibly common. According to the World Health Organization (WHO), about 3.8 billion people under the age of 50 globally have HSV-1.

In addition, an estimated 520 million people aged 15 to 49 have herpes simplex virus type 2 (HSV-2), which is the primary cause of genital herpes. Though the majority of people with herpes experience no symptoms or only mild ones, many may unknowingly transmit the virus to others.

The study at Uppsala University focused on how herpes might influence cognitive health in older adults. Over a 15-year period, researchers tracked 1,000 senior participants and monitored changes in their cognitive abilities.

Their findings suggest that herpes infection could be linked to an increased risk of dementia, which is consistent with previous studies hinting at such a connection.

Although the exact reasons behind this potential relationship are still unclear, scientists believe that recurring herpes flare-ups may cause inflammation in the brain. Chronic brain inflammation is known to be a key factor in neurodegenerative diseases like Alzheimer’s.

This discovery raises concerns about how infections we contract earlier in life might shape our brain function as we age.

Dementia is a general term used for conditions that cause a significant decline in cognitive function, severely impacting daily life. According to the Alzheimer’s Association, dementia affects more than 55 million people worldwide, with nearly 10 million new cases diagnosed annually. Experts predict that this number will grow to 78 million by 2030. The search for risk factors linked to dementia is therefore crucial, with some researchers now exploring the impact of infections like herpes on long-term brain health.

While herpes is typically seen as a minor health concern, the potential for it to influence cognitive decline decades later is an unsettling possibility. Dementia occurs when brain cells are damaged to the point where they can no longer communicate properly, resulting in memory loss, confusion, and a decline in cognitive abilities. Alzheimer’s disease, the most common type of dementia, tends to affect the hippocampus, a part of the brain responsible for memory and learning.

Herpes is particularly concerning because, after the initial infection, the virus can remain dormant in the body. It travels along nerve pathways and can reactivate later in life, causing further complications. The HSV-1 strain, responsible for oral herpes, is especially worrisome in relation to dementia risk. Some researchers believe that recurring viral reactivations over time could lead to brain inflammation, which in turn may increase the likelihood of cognitive decline.

“We don’t yet have clear answers about whether herpes directly causes dementia or whether the virus increases the risk in some indirect way,” said Erika Vestin, lead author of the study. While the connection between herpes and dementia is strong, scientists still need to determine if the virus is a direct cause of cognitive decline or if it simply makes individuals more vulnerable to it.

For those with herpes, experts caution that these early findings do not mean everyone with the infection will develop dementia. Herpes is widespread, but dementia remains far less common. Well-established risk factors for dementia, such as diabetes, hypertension, smoking, and physical inactivity, are still far more significant in determining the risk of cognitive decline in the future.

Despite the promising nature of these findings, additional research is needed to fully understand whether herpes infections are a definite risk factor for dementia. More clinical trials are required to confirm the link between the two. In the meantime, health organizations like WHO recommend basic measures to reduce the risk of spreading herpes, especially in intimate relationships.

To reduce the chances of transmitting herpes, it is advisable to:

Discuss your herpes status openly with your partner.

Avoid sexual activity during an outbreak and always use a condom.

Do not share items that may have come into contact with saliva (such as utensils, toothbrushes, or towels).

While the link between herpes and dementia remains a subject of ongoing study, the discovery serves as a reminder that our health is interconnected in ways we are still learning to understand. Researchers are continuing to investigate how infections may affect cognitive function over the long term, and what steps can be taken to reduce risk and improve brain health as we age.