I was having lunch with a creative director who makes ads starring what you might respectfully call a mature actress. "So how much touching up do you do?" I asked, and it occurred to neither of us that the question might have any meaning other than a digital one.

My creative rolled his eyes. "Oh my God, loads," he said wearily. "It's like trying to iron a prune." And we went on eating our sushi. Because there's really nothing at all exceptional about airbrushing in ads. The degree was the only point worth discussing.

Everyone knows that advertising images aren't really real. Mascara models don't have inch-long lashes. Cheryl Cole has falsies (in her hair). Twiggy is 60, not 40, with wrinkles to match. We understand all this. We know there's trickery involved. We know that computers can rub off spots, scour out wrinkles, melt off pounds. We get that what you see is not what you get.

So what's the problem? Well, perhaps we're not all so savvy about the realities of the media fantasy according to a new report from the Royal College of Psychiatrists. They're blaming manipulated images of women for fuelling eating disorders and insecurities in young people. And now the Royal College is calling for a kitemark on digitally enhanced photographs to raise awareness of how often such manipulation takes place and to highlight images of "unattainable physical perfection".

At the same time a Home Office-commissioned study into the early sexualisation of children has also suggested that digitally altered photographs should display ratings symbols to show the extent to which the images have been doctored. And wouldn't you just know it: MPs are piling in behind the experts, with 33 of them signing a Commons motion demanding that the ad industry bring in a kitemarking system for retouched images.

The critics argue that our aesthetic benchmarks have been warped by technology and its deployment to improve the images we see presented in advertising and the media every day. Apparently we may now have unrealistic standards of beauty; most of us fail to measure up, and the young and the vulnerable are feeling the strain.

Like so many cultural problems that are laid at adland's door, this one is a thoroughly complex and serious issue that has been reduced down to neat headlines and another blunt attack on the advertising industry.

But this is the climate in which the industry must now operate, and advertisers do need to be more sensitive than ever to the value systems their ads can help create.

Of course advertising should not seek to mislead; that would be in breach of the industry's own rule book. But the advertising regulators are armed with the tools to prevent and deal with any abuses.

So the ads that do break the rules (like Johnson & Johnson's recent ad for Clean & Clear, demonstrating the brand's impressive acne fighting powers with an "after" shot that had been airbrushed) get slapped down and made an example of.

But the thing is, advertising images don't need to be misleading to have a potentially harmful effect on how young people in particular feel about themselves and their bodies. Blaming adland for problems like body dysphoria or eating disorders might be ridiculously unfair, but it's true that too many ads feature too-perfect models. Though most of us understand that the images aren't real, their proliferation makes the ad industry ever more vulnerable to attack from pressure groups and vote-hungry politicians.

Every time an ad uses digital technology not simply to tidy up images but to twist reality into an unobtainable image of perfection, the threat of a kitemark system – or worse – takes a step closer. This, though, is one threat to advertising freedoms that the industry itself can head off. It's time to be a little more judicious with the airbrush.

Best In Show: Department for Transport (Abbott Mead Vickers BBDO)

Ads that try to encourage us not to do dangerous things, like drink and drive, or break the speed limit, tend to use horrifying images to shock us into submission. Sometimes, though, we just put our fingers in our ears and hum loudly till they've gone away. So this ad telling us to pay more attention to motorcyclists takes a more positive approach. The result is a lovely, gentle, thought-provoking ad that reminds us to look out for people like "Dave, new dad". A serious ad with an important message that's actually a joy to watch.