Oral sex is leading cause of increasing U.S. cancer rates, compared to tobacco use in other nations

Oral sex could be hazardous to your health.

So say researchers who note that oral cancer stemming from the human papilloma virus is more common in the U.S. than oral cancer caused by abusing tobacco.

Researchers found a 225% increase in oral cancer cases in the U.S. from 1974 to 2007, mainly among white men, said Maura Gillison, a cancer researcher at Ohio State University.

The more oral-sex partners a man had, the greater his cancer risk, Gillison told a meeting of the American Association for the Advancement of Science.

Tobacco use remains the leading cause of oral cancer in the rest of the world.

There as many as 150 different types of human papilloma viruses, and about 40 of those can be sexually transmitted, according to the National Cancer Institute.

HPV infections often go undetected and are the main cause of cervical cancer in women.

Scientists are examining whether Gardasil and Cervarix, the HPV vaccines approved to prevent genital warts and cervical cancer, could have a significant impact on oral cancer.

In the meantime, researchers are urging doctors and educators to start talking to teens in particular about the risks of oral sex.