No health study can undermine our faith in what we should be eating

For students of health reporting in the media, last week's headlines over coverage of the latest scientific study into the relationship between cancer and what we eat – or lack of it – were a particular joy.

It comes down to one word: glee. Since 2003 the Department of Health had been telling us that eating five portions of fruit or vegetables a day would help protect against cancer. Now, here was a major nine-year study involving hundreds of thousands of people which found the impact to be marginal. "Fruit diet won't fight cancer," boomed the Mirror; "5-a-day of little benefit," crowed the Daily Record.

Put aside the fact that even the authors of the study said their findings should be treated with caution; nine years may be an eternity in media land, but is as nothing in the world of cancer, plus there was very little follow-up on the all-important lifestyles of the subjects. What was most intriguing was the way the newspaper response highlighted just how fundamental a part of our lives that five-a-day advice has become. We all know what we're supposed to be eating and, regardless of its impact on the big C, that is still a major victory for state intervention in our health.

The fact is that, however much governments may wish it otherwise, it is very difficult for Whitehall to influence our diet, short of introducing rationing. We are instinctively suspicious of that sort of malarkey, for it smacks of attempts to engineer the personal. Talk to those who work in the field of public health and they will tell you that the cost of giving everybody in the country free gym membership for life plus a shiny new pair of trainers would, in the long term, be far smaller than the cost of treating the cancers, heart disease and diabetes that result from our failure to look after ourselves. If only they could ban not just smoking – a no-brainer – but McDonald's, KFC, sweet shops, pubs and the rest, the government would have so much more to spend on other things.

But that sounds like pure, old-fashioned, Soviet-style social engineering and will never fly. Instead, following advice from the World Health Organisation dating from 1990, we have the five-a-day campaign. It was introduced in 2003 and costs less than £1m a year of public money to run. It succeeds because the message is intuitive. In what way could eating loads of fresh fruit and veg not be good for you?

Arguing against it would be like trying to argue against the virtues of world peace. As a result, both the food industry and the supermarkets, always keen on a cheap marketing point, have done most of the government's work for it, slapping the news that products from smoothies to a bag of dried raisins could help you reach your target.

Are we actually following that advice? Well no, not yet. The first major study into our nutrition, released earlier this year, showed adults are on about 4.4 pieces of fruit and veg a day. Still, it's getting there. Ask most people why they pay any attention to the advice and they won't give you statistics on incidences of cancer. They won't draw you graphs of diabetes onset or heart disease mortality. They'll tell you it's because it's better for them. The good news is that no number of inky headlines like the ones we saw last week will change that.

Thanks to guardian.co.uk who have provided this article. View the original here.