Frank discussion in magazines of issues including sex, Aids and sexual abuse is "a reflection of our times", replacing previous generations' shame and ignorance, says Nicholas Tucker in his introduction to the report from the National Centre for Research in Children's Literature at Roehampton Institute.
"Ignorance is no longer an option," he says - but the glossies must use their power responsibly. "Seeking to replace former ignorance merely with shallow sexual knowingness could be altogether less of an advance."
Later in the document, researcher Pat Pinsent asks: "Are these magazines destroying our daughters' innocence, and encouraging them to form sexual relationships before they are ready for them?" but she concludes that "beneath a veneer of sophisticated sexual knowledge, the readers . . . are much the same as they always were; far from encouraging promiscuity, the stories and features often provide a powerful inducement to 'wait till you are ready'."
A greater cause for anxiety, she thought, was the magazines' "consumerist values" and their tendency to reflect a mainly white world.
Roehampton researchers found last year that 12 to 16-year-old girls gathered a powerful message against drug and solvent abuse from magazines such as Mizz, Sugar and J17.
The new report continues the past year's debate over sexual content which has led to the magazine publishers setting up their own regulatory body, the Teenage Magazine Arbitration Panel (TMAP). It has drawn up guidelines on coverage of sexual subjects (including advice columns) which must be followed if more than 25 per cent of a title's readers are under 15.
The panel, chaired by Dr Fleur Fisher, a former chair of the British Medical Association's ethics committee, has heard around 112 complaints since it was set up last year, and has upheld two.
The panel says it is likely that "changes in teenage sexual behaviour predate the emergence of the teenage magazine market . . . We have no firm evidence to suggest that appropriate and professional advice in teenage magazines encourages readers to enter into sexual relationships."
"We reflect the agenda, not set it," Lee Kynaston, editor of 19 and former features editor of Mizz, said this week at a seminar organised by the Institute of Public Relations.
Although 19 is aimed at 16 to 20-year-olds and technically outside TMAP's remit, it could attract younger readers. Mr Kynaston's outline of a typical reader "possibly a bright sixth-form college student, with style, wit and intelligence" also suggests that young women (and the male readers who say they borrow their sisters' magazines) need information and reassurance about sex and relationships.
"We get letters from 17 and 18-year-olds who are shockingly ill-informed, who do not know the basics of safe sex. One reason teenagers are turning to magazines is that schools and parents are not providing the sort of sex education and relationship counselling they need."
Defending titillating coverlines (this month's include "I was filmed having sex"), he said the magazine did not present promiscuity as normal or desirable.
"We did a feature on an 18-year-old who had slept with 400 men but we treated it as a cautionary tale. But we have to be responsible without moralising - if you start wagging your finger, teenagers switch off."
Mizz, clearly aimed at younger readers with its 50p cover price, free pendant and pop posters, has an environmental issues page, Planet Mizz, including an interview with Swampy. Sex is played down, but the environmentally hazardous topic of farts dominates several pages of the current issue.
Teenage Girls and their Magazines, by Pat Pinsent and Bridget Knight, Pounds 5 plus Pounds 1 pp from the National Centre for Research in Children's Literature, Downshire House, Roehampton Lane, London SW15 4HT. The Teenage Magazine Arbitration Panel is based at the Periodical Publishers Association, Queens House, 28 Kingsway, London WC2B 6JR