Oscar awardee Michael Douglas blamed oral sex for his throat cancer.

The actor was diagnosed with throat cancer in August 2010 and everyone thought that it was a result of his tobacco smoking habit but during an interview with the Guardian, he revealed the real culprit-oral sex.

So how can oral sex cause throat cancer? Blame it on the humano papilloma virus or HPV that cause genital warts to both men and women.  It has over 100 types but 40 of them are concentrated in the reproductive organs. Carriers would not usually be aware that they have it and unfortunately men are more vulnerable to oral HPV infections than women.

Michael Douglas, married to Catherine Zeta-Jones, thought that his cancer was triggered by stress because of his son's imprisonment but after visiting a doctor, who happened to be a close friend in Montreal, they discovered that stress was not the cause.

"I will always remember the look on his face," Douglas told in the interview. "He said: 'We need a biopsy.' There was a walnut-size tumour at the base of my tongue that no other doctor had seen."

They had the tumor analyzed and discovered that it was already on its fourth stage-the stage where cancer cells have already spread in other organs of the body. The actor underwent eight weeks of chemotherapy and radiation where he lost almost 45 lbs in the process because he refused to eat using a feeding tube.

Lucky for him, the treatment worked and he survived the cancer. He still have himself checked every six months although doctors say that there is only about 5 percent chance of the cancer recurring.

Anyone can reduce their risk of developing HPV by using a condom during intercourse and limiting the number of sexual partners. There is also HPV vaccine available that may help prevent people from catching genital warts and cervical cancer as well.