Dec. 19, 2007— -- Teenagers who receive any kind of sex education -- whether it's comprehensive or abstinence-only -- are more likely to delay sexual intercourse until after they turn 15, according to a new report.
But some sexual health experts worry that the study's failure to distinguish between comprehensive and abstinence-only approaches could give the public the wrong idea about the efficacy of simply telling kids not to have sex.
In the study, released Wednesday in the Journal of Adolescent Health, researchers from the Center for Disease Control and Prevention analyzed responses from more than 2,000 teenagers between the ages of 15 and 19 to the 2002 National Survey of Family Growth.
They found that boys in this age bracket who received formal sex education -- either in schools, churches or community organizations -- were 71 percent less likely to have sex before age 15. Girls aged 15 to 19 who received formal sex education were 59 percent less likely to have sex before age 15.
Formal sex education also seems to lead to safer sex, the study found. Males attending school who had received sex education were almost three times more likely to use birth control the first time they had sex -- though no such associations were found among females.
"Formal sex education was particularly beneficial for youth who are traditionally considered to be at high risk for adverse sexual health outcomes, such as sexually transmitted diseases or unplanned pregnancies," says lead study author Trisha Mueller, an epidemiologist at the CDC's Division of Reproductive Health.
"Sex education should be continued to be supported in formal settings, such as schools, and to be the most effective, should occur before youth engage in sexual intercourse for the first time."
Sexual health experts not affiliated with the study say it is an important addition to continuing evidence that sex education works to promote healthier behaviors.
"This study expands on studies that have shown that sexuality education can delay the onset of sexual intercourse -- once again dispelling the myth that early sexuality education might increase sexual activity," explains Eli Coleman, director of the program in human sexuality at the University of Minnesota Medical School. "This study shows that sexuality education leads to more responsible sexual behavior."
Pepper Schwartz, professor of sociology at the University of Washington in Seattle, agrees.
"I am thrilled to have this study because it confirms, in some ways, the bottom-line fact: talking about sex, and giving information about sex, makes kids more thoughtful about it and more likely to be able to form a moral code and plan of action -- rather than unconscious reaction."
But the fact that the study does not differentiate between comprehensive and abstinence-only programs gives some experts pause.
"It is unfortunate that this study did not look carefully at the potential differences in efficacy between comprehensive and abstinence-only sexuality education," Coleman says.
Mueller says that since the analysis was based on the 2002 survey data -- which asked participants whether they had "ever received any formal instruction on how to say 'no' to sex" and whether they had ever received formal education on birth control methods -- the researchers' ability to distinguish between types of sex education was limited.
"We agree that it would be extremely useful to compare the effect of abstinence-only education to comprehensive sex education," she says. "However, we decided not to do so in this analysis because we felt that the question related to 'how to say no to sex' was a poor proxy measure for abstinence-only education. ... For this reason, we have chosen to look at any sex education versus no sex education for the purposes of this manuscript."
Coleman adds that past research still points to comprehensive sex education as the healthiest approach.
"From other research, the findings are clear," he says. "Comprehensive sexuality education approaches are effective in delaying the onset of sexual activity and have the advantage of increasing the likelihood of individuals acting responsibly by protecting themselves and their partners by using condoms and other forms of contraceptives to prevent sexually transmitted infections and unplanned pregnancies."
Although the content of sex education -- whether abstinence-only or comprehensive -- is still debated, a 2004 study indicated that 93 percent of Americans support some form of sex education in schools.
Other recent studies on sex ed have shown that providing youths with the skills and knowledge to make responsible decisions about sex may help to reduce the more than 750,000 teen pregnancies and the more than 9 million cases of sexually transmitted diseases that occur yearly among Americans aged 15-24.
Earlier studies conducted in the 1970s through 1990s, however, seemed to suggest that sex education had little or no effect on the likelihood of young people engaging in sexual intercourse.
Until this report, there had been no recent national studies conducted to assess the effect of sex education on the sexual behaviors of youth -- a situation that health experts say begs for further research to evaluate the most effective content and implementation of sex education.
"Before the authors [of this study] make a pitch for mandatory sex education in schools," says Dr. Andre Guay, director of the Center for Sexual Function/Endocrinology at the Lahey Clinic, "they have to compare data from homes where sex education is talked about and taught, perhaps as an adjunct to the school program, but also to compare to those children who only receive home schooling in sexual education."
Judy Kuriansky, author of "The Complete Idiot's Guide to Dating" and "Generation Sex," says the gender differences seen in the responses for boys and for girls in this study are also intriguing.
"It is interesting that [sex education] is more effective for boys than girls," she says. "I think this is because girls still are pressured into having sex to please a boyfriend and to keep the boyfriend."
As for the overall findings of the study, Kuriansky says the research shows that "love can wait if [teens] learn about sex."