Caution: Frequently Engaging in Sexual Activity Could Result in Changes to the Brain and Increase Dementia Risk.
A recent study is highlighting worries regarding an uncommon yet significant risk associated with a prevalent sexual practice — the possibility of brain injury and dementia resulting from the herpes simplex virus type 1 (HSV-1).
HSV-1, the virus that causes oral herpes, is harbored by nearly four billion individuals globally. While it predominantly leads to cold sores, researchers now recognize a perilous pathway through which the virus can access the brain — through the nasal passage during oral sexual activity.
Professor Deepak Shukla from the University of Illinois Chicago, who directed the research, noted that HSV-1 particles can infiltrate the nose when it comes into contact with an infected partner’s saliva or skin during oral sex. Once in the nasal cavity, the virus may proceed directly to the brain, raising the risk of encephalitis, brain injury, and possible dementia.
The study, featured in the journal *mBio*, also discovered a crucial human enzyme, **heparanase (HPSE)**, which may render nasal HSV-1 infections particularly detrimental. Although heparanase generally aids in clearing injured cells, HSV-1 seems to exploit the enzyme to escalate inflammation in the brain.
“For most individuals, HSV-1 results in sporadic cold sores and is relatively harmless,” Professor Shukla remarked. “However, if the infection moves through the nasal route to the brain, it can result in much more severe consequences.”
To investigate this hypothesis, Shukla’s team performed experiments on mice by inserting HSV-1 into their noses. Mice with standard heparanase levels exhibited severe symptoms, including nasal swelling, respiratory difficulties, and ultimately, death. Brain examinations indicated nerve damage, heightened inflammation, and irregular activity in regions associated with smell and virus entry.
Behavioral alterations were also observed, encompassing memory impairment, anxiety-like behaviors, and balance issues — all occurring within six months of infection.
Although herpes simplex encephalitis (HSE) is uncommon — impacting approximately two to four individuals per million — researchers suspect that instances of nasal HSV-1 are likely underreported. The virus can remain latent in the brain and may contribute to conditions such as Alzheimer’s disease later in life.
Shukla stressed that the consequences can vary widely based on an individual’s immune resilience and the frequency of their outbreaks.
“Our results act as a cautionary tale,” he stated. “Unchecked herpes can lead to enduring behavioral challenges, motor dysfunction, and coordination difficulties. It is essential to comprehend how the virus operates and the potential severity it can reach under certain circumstances.”
Professor Deepak Shukla from the University of Illinois Chicago, who directed the research, noted that HSV-1 particles can infiltrate the nose when it comes into contact with an infected partner’s saliva or skin during oral sex. Once in the nasal cavity, the virus may proceed directly to the brain, raising the risk of encephalitis, brain injury, and possible dementia.
The study, featured in the journal *mBio*, also discovered a crucial human enzyme, **heparanase (HPSE)**, which may render nasal HSV-1 infections particularly detrimental. Although heparanase generally aids in clearing injured cells, HSV-1 seems to exploit the enzyme to escalate inflammation in the brain.
“For most individuals, HSV-1 results in sporadic cold sores and is relatively harmless,” Professor Shukla remarked. “However, if the infection moves through the nasal route to the brain, it can result in much more severe consequences.”
To investigate this hypothesis, Shukla’s team performed experiments on mice by inserting HSV-1 into their noses. Mice with standard heparanase levels exhibited severe symptoms, including nasal swelling, respiratory difficulties, and ultimately, death. Brain examinations indicated nerve damage, heightened inflammation, and irregular activity in regions associated with smell and virus entry.
Behavioral alterations were also observed, encompassing memory impairment, anxiety-like behaviors, and balance issues — all occurring within six months of infection.
Although herpes simplex encephalitis (HSE) is uncommon — impacting approximately two to four individuals per million — researchers suspect that instances of nasal HSV-1 are likely underreported. The virus can remain latent in the brain and may contribute to conditions such as Alzheimer’s disease later in life.
Shukla stressed that the consequences can vary widely based on an individual’s immune resilience and the frequency of their outbreaks.
“Our results act as a cautionary tale,” he stated. “Unchecked herpes can lead to enduring behavioral challenges, motor dysfunction, and coordination difficulties. It is essential to comprehend how the virus operates and the potential severity it can reach under certain circumstances.”
