Janet Street-Porter: Why commerce may not be good for you

Yesterday, the Advertising Standards Agency upheld a complaint about claims that Unilever Bestfoods made for Flora pro.activ margarine. If you ploughed through the agency's findings in detail you would end up thoroughly confused, and it's only when you struggle through to the end of the report and read the blurb for Flora pro.activ which breached the CAP (Committee for Advertising Practice) code's clauses relating to "substantiation and truthfulness" the penny drops. Unilever claimed that the margarine "helps keep blood vessels healthy".

The ASA findings stated that although folic acid and B vitamins (ingredients trumpeted by Unilever) do help keep blood vessels healthy, the amounts used in clinical trials do not relate to the amounts present in this margarine. I've eaten Flora for years, feebly believing it was better for my arteries than butter. But is it? Flora pro.activ is not a magical cure for cholesterol.

In fact, the "healthy" plant sterols it contains are present in every day fruit and vegetables, so why not eat them instead? Recent research shows that people on a Mediterranean diet, with olive oil and plenty of fruit and vegetables have less heart disease than people who eat loads of meat and dairy products. What especially annoyed me about Flora was the advertising campaign featuring Lulu, where she wrote a daily "healthy eating" diary in which Flora pro.activ featured heavily along with little plugs for her new album.

As Lulu, pictured, looks fantastic for her age, this was extremely clever advertising - and, having known her for years, I can attest that her toned body and high level of fitness are down to daily yoga, and an excellent diet. I have never discussed Flora with Lulu, but no matter. Lulu, like Twiggy, is being used to market to the over-50s, with great effect.

We all want to live longer and look youthful and these two icons tick all the right boxes. But can't we achieve good health in other, cheaper ways? On the Flora website, the pro.activ products are talked about as if they possess medicinal qualities.

Under "frequently asked questions" we are told that if you eat three portions every day as part of a healthy diet, "Flora pro.activ cholesterol-lowering foods are clinically proven to lower chloresterol within three weeks".

There's more: "Because Flora pro.activ can significantly reduce LDL cholesterol, your doctor may need to take this into consideration when planning your treatment ...." Unilever will have to amend its advertising, but don't expect this clever blend of medical information and "helpful advice" to change fundamentally.

Meanwhile, doctors have voiced concerns over plans from the Department of Health to locate walk-in clinics in supermarkets. The blurred line between advertising and health claims for products such as margarine have been exposed by the ASA's findings.

Can you imagine how supermarkets would alter their layouts to accommodate all sorts of products en route to and from surgeries within their premises? They would be able to auction the "healthy" slots at a premium. Commerce and health don't mix. Health care should be ring-fenced and take place in non-profit-driven surroundings.

Is it time for Diana, the musical?

Elena Roger is mesmerising as Evita in Michael Grandage's excellent new production at the Adelphi theatre - and I hope that the World Cup is not affecting ticket sales, although many West End theatres are really struggling this week, with many offering cheap deals and giving away seats. Watching Evita leads to the question, when will we have a West End Diana musical? In many respects this show mirrors Diana's life and her charismatic connection with ordinary people. Diana's life story would make a great show as it contains all the key elements: adultery, loads of frocks, dozens of servants in a whole variety of palatial settings, and a tragic demise. Once the official inquiry into her death is complete, surely a brave composer will rise to the task. I don't think it will be Mr Lloyd Webber - he might be stripped of his knighthood.

* Damien Hirst's pickled shark,created in 1991, is disintegrating. Now worth an astonishing £6.5m, the shark has changed shape and floats in a murky gloom - probably because the artist didn't use a strong enough solution of formaldehyde. Its current owner, American millionaire Steve Cohen, is said to be happy his work will have to be "renewed". And so he should be. What he bought was an idea, authenticated by probably the most exciting artist in the world. As long as Hirst supervises the installation of shark2, what's the problem? A few years ago, a friend and I attended a Yoko Ono retrospective at the Museum of Modern Art in Oxford. One piece consisted of a hammer and a pile of nails. When we picked up the hammer, a guard swiftly told us we couldn't bash in a nail because that would interfere with the original concept. Tosh. Conceptual art is all about interaction between the spectator and the artist. I'm sure the huge installations by the late, great Joseph Beuys, for example, have elements renewed regularly.