Caution: Widespread Sexual Behavior Could Result in Brain Alterations and Dementia
A recent study has brought attention to a rare 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 carried by nearly four billion individuals globally. While it mainly results in cold sores, researchers have now uncovered a perilous pathway that allows the virus to reach the brain – through the nasal route during oral sexual encounters.
Professor Deepak Shukla from the University of Illinois Chicago, who spearheaded the study, explained that HSV-1 particles can access the nasal cavity when it comes into contact with an infected partner’s saliva or skin during oral sex. Once it infiltrates the nasal area, the virus can travel directly to the brain, leading to potential risks of encephalitis, brain damage, and possibly dementia.
This research, published in the journal *mBio*, also identified a significant human enzyme, **heparanase (HPSE)**, that may render nasal HSV-1 infections particularly harmful. While heparanase typically assists in removing damaged cells, HSV-1 seems to exploit this enzyme to increase inflammation in the brain.
“For the majority of people, HSV-1 results in occasional cold sores and isn’t a threat,” stated Professor Shukla. “However, if the infection ascends through the nasal passage to the brain, it can become much more severe.”
To investigate this hypothesis, Shukla’s team performed experiments on mice by administering HSV-1 intranasally. Mice with normal levels of heparanase exhibited severe symptoms such as nasal swelling, respiratory difficulties, and ultimately, death. Brain assessments revealed nerve damage, heightened inflammation, and unusual activity in regions associated with smell and viral entry.
There were also notable behavioral changes, including memory loss, anxiety-like behaviors, and balance issues—all occurring within six months of infection.
Although herpes simplex encephalitis (HSE) is uncommon—impacting roughly two to four individuals per million—researchers suspect that cases of nasal HSV-1 are likely underreported. The virus may remain latent in the brain and contribute to diseases like Alzheimer’s later in life.
Shukla stressed that the effects can vary notably based on an individual's immune system and the frequency of outbreaks.
“Our findings act as a caution,” he remarked. “Uncontrolled herpes can result in long-term behavioral complications, motor dysfunction, and coordination challenges. It’s crucial to comprehend how the virus operates and the serious implications it can have under specific circumstances.”
Professor Deepak Shukla from the University of Illinois Chicago, who spearheaded the study, explained that HSV-1 particles can access the nasal cavity when it comes into contact with an infected partner’s saliva or skin during oral sex. Once it infiltrates the nasal area, the virus can travel directly to the brain, leading to potential risks of encephalitis, brain damage, and possibly dementia.
This research, published in the journal *mBio*, also identified a significant human enzyme, **heparanase (HPSE)**, that may render nasal HSV-1 infections particularly harmful. While heparanase typically assists in removing damaged cells, HSV-1 seems to exploit this enzyme to increase inflammation in the brain.
“For the majority of people, HSV-1 results in occasional cold sores and isn’t a threat,” stated Professor Shukla. “However, if the infection ascends through the nasal passage to the brain, it can become much more severe.”
To investigate this hypothesis, Shukla’s team performed experiments on mice by administering HSV-1 intranasally. Mice with normal levels of heparanase exhibited severe symptoms such as nasal swelling, respiratory difficulties, and ultimately, death. Brain assessments revealed nerve damage, heightened inflammation, and unusual activity in regions associated with smell and viral entry.
There were also notable behavioral changes, including memory loss, anxiety-like behaviors, and balance issues—all occurring within six months of infection.
Although herpes simplex encephalitis (HSE) is uncommon—impacting roughly two to four individuals per million—researchers suspect that cases of nasal HSV-1 are likely underreported. The virus may remain latent in the brain and contribute to diseases like Alzheimer’s later in life.
Shukla stressed that the effects can vary notably based on an individual's immune system and the frequency of outbreaks.
“Our findings act as a caution,” he remarked. “Uncontrolled herpes can result in long-term behavioral complications, motor dysfunction, and coordination challenges. It’s crucial to comprehend how the virus operates and the serious implications it can have under specific circumstances.”