Caution: Typical Sexual Activity Might Result in Brain Alterations and Dementia
A recent study has brought to light worries regarding a rare yet significant risk associated with a prevalent sexual practice — the possibility of brain injury and dementia due to the herpes simplex virus type 1 (HSV-1).
HSV-1, the virus that causes oral herpes, is estimated to be carried by nearly four billion individuals globally. While it generally results in cold sores, researchers have discovered a concerning pathway through which the virus can access the brain — via the nasal passage during oral sexual activities.
Professor Deepak Shukla from the University of Illinois Chicago, who led the study, indicated that HSV-1 particles can enter the nose if it comes into contact with the saliva or skin of an infected partner during oral sex. Once in the nasal cavity, the virus might travel directly to the brain, which poses threats of encephalitis, brain damage, and potentially dementia.
The research, published in the journal *mBio*, also identified a significant human enzyme, **heparanase (HPSE)**, which may make nasal infections of HSV-1 particularly harmful. While heparanase generally aids in clearing out damaged cells, HSV-1 seems to exploit this enzyme to heighten inflammation in the brain.
“For most individuals, HSV-1 leads to occasional cold sores and is not considered dangerous,” noted Professor Shukla. “However, if the infection ascends through the nasal passage to the brain, the consequences can be much more severe.”
To investigate this hypothesis, Shukla’s team performed experiments on mice by administering HSV-1 directly into their noses. Mice exhibiting normal heparanase levels developed severe symptoms, such as nasal swelling, breathing difficulties, and ultimately death. Autopsies of the brains revealed nerve damage, heightened inflammation, and irregular activity in regions associated with smell and viral entry.
Behavioral alterations were also observed, including memory impairment, anxiety-like behaviors, and balance issues — all within six months post-infection.
Though herpes simplex encephalitis (HSE) is uncommon, impacting around 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 conditions like Alzheimer’s disease as individuals age.
Shukla stressed that the impact can vary greatly depending on a person's immune system functionality and the frequency of outbreaks.
“Our findings act as a cautionary tale,” he stated. “Unchecked herpes can result in long-lasting behavioral issues, motor dysfunction, and coordination challenges. It’s crucial to grasp how the virus operates and the severity it can reach under certain circumstances.”
Professor Deepak Shukla from the University of Illinois Chicago, who led the study, indicated that HSV-1 particles can enter the nose if it comes into contact with the saliva or skin of an infected partner during oral sex. Once in the nasal cavity, the virus might travel directly to the brain, which poses threats of encephalitis, brain damage, and potentially dementia.
The research, published in the journal *mBio*, also identified a significant human enzyme, **heparanase (HPSE)**, which may make nasal infections of HSV-1 particularly harmful. While heparanase generally aids in clearing out damaged cells, HSV-1 seems to exploit this enzyme to heighten inflammation in the brain.
“For most individuals, HSV-1 leads to occasional cold sores and is not considered dangerous,” noted Professor Shukla. “However, if the infection ascends through the nasal passage to the brain, the consequences can be much more severe.”
To investigate this hypothesis, Shukla’s team performed experiments on mice by administering HSV-1 directly into their noses. Mice exhibiting normal heparanase levels developed severe symptoms, such as nasal swelling, breathing difficulties, and ultimately death. Autopsies of the brains revealed nerve damage, heightened inflammation, and irregular activity in regions associated with smell and viral entry.
Behavioral alterations were also observed, including memory impairment, anxiety-like behaviors, and balance issues — all within six months post-infection.
Though herpes simplex encephalitis (HSE) is uncommon, impacting around 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 conditions like Alzheimer’s disease as individuals age.
Shukla stressed that the impact can vary greatly depending on a person's immune system functionality and the frequency of outbreaks.
“Our findings act as a cautionary tale,” he stated. “Unchecked herpes can result in long-lasting behavioral issues, motor dysfunction, and coordination challenges. It’s crucial to grasp how the virus operates and the severity it can reach under certain circumstances.”
