A recent study found that abstinence-only sex education programs delayed the onset of sexual activity in pre-teens and reduced the amount of sexual activity among those who were sexually active. The New York Times reports that the study is already beginning to shake up the debate over how to best reduce incidence of sexually transmitted infections and pregnancy in teenagers.

University of Pennsylvania-led study was published this month in The Archives of Pediatric & Adolescent Medicine.

“This is a rigorous study that means we can now say that it’s possible for an abstinence-only intervention to be effective,” said John. B. Jemmott III, PhD, the University of Pennsylvania professor who led the study. “That’s important because for some populations abstinence is the only acceptable message.”

The study followed 662 African-American sixth and seventh graders at urban middle schools who attended one of four types of sex education and health education classes. It found that about a third of the students who participated in a weekend abstinence-only class began having sex within two years compared with about half of those who were assigned to either a general health class that did not talk about sex education or a class that focused solely on safer sex. This also compares with about 42 percent of students attending a comprehensive sex education class that included both safer sex and abstinence. Students were paid $20 per session to attend the classes as well as follow-up and evaluation sessions. The abstinence-only classes covered HIV, abstinence and ways to resist pressure to have sex.

“Because African Americans tend to have a higher rate of early sexual initiation than others, we thought that within two years, a reasonable number would start having sex,” Jemmott said. “If we went younger, we couldn’t show that intervention works.”

In his proposed budget for the 2011 fiscal year, President Barack Obama aims to eliminate federally funded abstinence-only education programs in place of a more comprehensive approach. The abstinence-only program in this study—unlike federal programs—did not advocate abstinence until marriage. The class also did not use moralistic terms to talk about sex in a negative light.

The Archives of Pediatric & Adolescent Medicine published an editorial to accompany the study results, advising that the results of a single study should not shape public policy and that lawmakers shouldn’t “selectively use scientific literature to formulate a policy that meets preconceived ideologies.”

“The results may be surprising to some in that the theory-based abstinence-only curriculum appeared to be as effective as a combined course and more effective than the safer-sex only curriculum in delaying sexual activity,” the editorial said. “None of the curricula had any effect on the prevalence of unprotected sexual intercourse or consistent condom use.”

According to the article, some longtime advocates of comprehensive sexual education are applauding these results.

“This new study is game-changing,” said Sarah Brown of the National Campaign to Prevent Teen and Unplanned Pregnancy, in a statement. “For the first time, there is strong evidence that an abstinence-only intervention can help very young teens delay sex and reduce their recent sexual activity as well. Importantly, the study also shows that this particular abstinence-only program did not reduce condom use among the young teens who did have sex.”