Scientists issue serious health warning over common sexual act that could 'lead to dementia'

A sexually transmitted infection that affects nearly two-thirds of the global population may 'lead to dementia', according to a new study.

Scientists from the University of Illinois Chicago have issued a serious health warning following research into herpes simplex virus type one (HSV-1) - which they found can be contracted inside and around the nose.

More commonly known as herpes, it causes painful blisters or ulcers, and it primarily spreads through skin-to-skin contact, and while it is treatable it is not curable.

HSV-1, more commonly known as herpes, infects almost two-thirds of the world population (Getty stock)

The World Heath Organization (WHO) explains that there are two types of the virus - type one, which is spread by oral contact and it causes infection in and around the mouth.

"It can also cause genital herpes. Most adults are infected with HSV-1," it adds.

Meanwhile, type two is spread by sexual contact and causes genital herpes.

However, the experts note there are cases in which HSV-1 has been spread through oral sex.

“If an infected individual is shedding virus via tears, it could reach the nasal cavity, where it could go more directly to the brain,” explained lead author of the paper, Dr Deepak Shukla.

HSV-1 is a lifelong infection that can be treated but not cured (Getty stock)

"I think it’s underdiagnosed and understudied, but the neurological consequences, we believe, are much more severe than you would normally see with fever blisters or ocular infection."

Using lab mice, scientists discovered that a protein called heparanase plays a big role in worsening conditions caused by HSV-1 - such as brain inflammation and behavior problems.

When the rodents were infected with HSV-1 through their nose, heparanase caused inflammation in the brain, which in turn led to problems with memory, anxiety, and movement.

Meanwhile, mice without heparanase had fewer of these issues.

The study - which was published in mBio toward the end of last month - concludes: "Our findings position HPSE as a potential therapeutic target for mitigating virus-induced neuroinflammation and neurobehavioral defects."

HSV-1 located in or around the nose may lead to dementia, according to the study (Getty stock)

“There is definitely nerve damage if you take the intranasal route, and the effects are long-term, which is alarming,” Shukla added.

Hemant Borase, a University of Illinois Chicago postdoctoral researcher and first author of the study, explained: "These insights open the door to potential therapeutic approaches to mitigate the effects of neuroinflammation and prevent long-term brain injury caused by viral infections."

While co-author of the paper, and research assistant professor in the College of Medicine, Chandrashekhar Patil weighed in on the subject.

"The virus reactivates throughout life; it’s a lifelong infection.

"So, I think this awareness will be really important among the large population which is carrying this virus."

However, it should be noted that the infection going to the brain is incredibly rare.