Teaching them only to "just say no," as Utah's schools are required to do, isn't enough. They also need information about contraception and the dangers of unprotected sex.

The Utah Health Department reports that, between 2001 and 2005, Utah recorded the largest increase in rates of sexually transmitted chlamydia and gonorrhea in the nation. Those most at risk are between the ages of 15 and 24.

The rate of gonorrhea, which can cause pelvic inflammatory disease, chronic pelvic pain and infertility, increased 195 percent. Strains of the disease are growing resistant to antibiotics, making treatment more difficult.

"We really don't have an obvious reason for the increase except that our young adults are having unprotected sex," said a health department specialist.

That may be due to the prevailing attitude in the Utah Legislature and among many parents that informing teens in school about condoms will encourage them to have sex at an earlier age. But research shows the folly of that belief.

A recent study commissioned by Congress that compared the sexual activity of students who attended abstinence-only classes and those who didn't has found that both groups started having sex at about the same age and had about the same number of sexual partners.

Earlier research has indicated that teenagers who receive comprehensive sex education that includes discussion of abstinence and contraception take a more cautious and mature approach. They become sexually active later and have fewer partners.

Abstinence is the only way to entirely avoid the inherent risks of sexual activity. It should be a vital part of any comprehensive sex-education program. But it is unrealistic to bank on abstinence-only education to stop young people from having sex. And abstinence-only doesn't help them avoid pregnancy and disease.

Utah teens need accurate information, through sex education in school, that encourages them to "say no," but also helps them stay safe if they decide to say "yes."