Oral sex is causing an "epidemic" of throat cancers in the US and UK.
Dr. Hisham Mehanna, from the University of Birmingham, says that 70 per cent of throat cancer cases are caused by human papillomavirus (HPV) - a normally harmless virus that is spread sexually and has been linked to a multitude of cancers.
Dr. Mehanna explained that people who have multiple oral sex partners have up to a nine-fold increased risk of suffering throat cancer.
He wrote in The Conversation: "Over the past two decades, there has been a rapid increase in throat cancer in the West, to the extent that some have called it an epidemic.
"This has been due to a large rise in a specific type of throat cancer called oropharyngeal cancer."
Dr. Mehanna continued: "HPV is sexually transmitted. For oropharyngeal cancer, the main risk factor is the number of lifetime sexual partners, especially oral sex.
"Those with six or more lifetime oral sex partners are 8.5 times more likely to develop oropharyngeal cancer than those who do not practice oral sex."