Caution: Frequent Sexual Activity Could Result in Brain Alterations and Dementia
A recent study is highlighting worries over a rare yet significant risk associated with a typical sexual activity — the possibility of brain damage and dementia due to the herpes simplex virus type 1 (HSV-1).
HSV-1, which causes oral herpes, is carried by nearly four billion individuals globally. While it generally leads to cold sores, researchers have recently discovered a concerning pathway through which the virus can access the brain—specifically, via the nasal route during oral sex.
Professor Deepak Shukla from the University of Illinois Chicago, who spearheaded the research, explained that HSV-1 particles can enter the nasal passages if saliva or skin from an infected partner comes into contact during oral sexual activities. Once in the nasal cavity, the virus may travel straight to the brain, raising the risk of encephalitis, brain damage, and potentially dementia.
The study, published in the journal *mBio*, also identified a crucial human enzyme, **heparanase (HPSE)**, that could make nasal HSV-1 infections particularly detrimental. Although heparanase typically functions to eliminate damaged cells, HSV-1 seems to exploit this enzyme to amplify inflammation within the brain.
“For most individuals, HSV-1 leads to occasional cold sores and is not harmful,” noted Professor Shukla. “However, if the infection ascends through the nasal route to the brain, it can become significantly more severe.”
To test this hypothesis, Shukla’s research team performed experiments on mice by introducing HSV-1 into their nasal cavities. The mice with typical levels of heparanase exhibited severe symptoms, such as nasal swelling, respiratory difficulties, and ultimately death. Brain examinations showed signs of nerve damage, heightened inflammation, and unusual activity in regions associated with smell and viral entry.
Changes in behavior were observed as well, including memory loss, anxiety-like behaviors, and balance issues—all occurring within six months post-infection.
Although herpes simplex encephalitis (HSE) is uncommon—affecting approximately two to four individuals per million—researchers suspect that nasal HSV-1 cases are often underrepresented. The virus may remain latent in the brain and contribute to conditions such as Alzheimer’s disease later in life.
Shukla stressed that the impact can vary widely based on a person’s immune strength and the frequency of their outbreaks.
“Our findings serve as a caution,” he stated. “Uncontrolled herpes can lead to long-term behavioral challenges, motor dysfunction, and coordination difficulties. It’s vital to grasp how the virus operates and the seriousness it may reach under specific circumstances.”
Professor Deepak Shukla from the University of Illinois Chicago, who spearheaded the research, explained that HSV-1 particles can enter the nasal passages if saliva or skin from an infected partner comes into contact during oral sexual activities. Once in the nasal cavity, the virus may travel straight to the brain, raising the risk of encephalitis, brain damage, and potentially dementia.
The study, published in the journal *mBio*, also identified a crucial human enzyme, **heparanase (HPSE)**, that could make nasal HSV-1 infections particularly detrimental. Although heparanase typically functions to eliminate damaged cells, HSV-1 seems to exploit this enzyme to amplify inflammation within the brain.
“For most individuals, HSV-1 leads to occasional cold sores and is not harmful,” noted Professor Shukla. “However, if the infection ascends through the nasal route to the brain, it can become significantly more severe.”
To test this hypothesis, Shukla’s research team performed experiments on mice by introducing HSV-1 into their nasal cavities. The mice with typical levels of heparanase exhibited severe symptoms, such as nasal swelling, respiratory difficulties, and ultimately death. Brain examinations showed signs of nerve damage, heightened inflammation, and unusual activity in regions associated with smell and viral entry.
Changes in behavior were observed as well, including memory loss, anxiety-like behaviors, and balance issues—all occurring within six months post-infection.
Although herpes simplex encephalitis (HSE) is uncommon—affecting approximately two to four individuals per million—researchers suspect that nasal HSV-1 cases are often underrepresented. The virus may remain latent in the brain and contribute to conditions such as Alzheimer’s disease later in life.
Shukla stressed that the impact can vary widely based on a person’s immune strength and the frequency of their outbreaks.
“Our findings serve as a caution,” he stated. “Uncontrolled herpes can lead to long-term behavioral challenges, motor dysfunction, and coordination difficulties. It’s vital to grasp how the virus operates and the seriousness it may reach under specific circumstances.”
