At pounds 1.35 a shot, it is said to provide energy and protection
What have Sean Connery, Lulu and the ex-guitarist from Duran Duran got in common, apart from a past more illustrious than the present? Answer: they have all popped into London's hippest health store, Planet Organic, to try out wheatgrass juice, the latest import from the United States - said to revitalise flagging bodies, if not flagging careers.

Indeed Planet Organic has been the driving force in introducing the British to wonders of wheatgrass - at a price. A whisky-sized shot of freshly squeezed grass (basically the shoots of ordinary wheat) will set you back pounds 1.35, while a full tray of grass for home consumption costs pounds 12.99 plus delivery. Alternatively, you can grow wheat and juice it yourself with a special electric juicer, a snip at pounds 450.

Wheatgrass devotees believe this is money well spent. They claim the juice has remarkable effects on the body, neutralising pollutants and clearing the digestive system, fighting free radicals and repairing cell damage, increasing energy levels; some claim it even helps prevent and cure serious illness such as cancer.

Over 70 per cent of wheatgrass is chlorophyll, the pigment plants use to convert sunlight into energy. Devotees say chlorophyll has a number of benefits for humans as well as plants, such as improving heart function, detoxifying the liver and bloodstream, and providing a particularly effective treatment for anaemia.

But can sprouted wheat really deliver so much? The plant, like many others, is certainly a good source of A, B, C and E vitamins, amino acids and minerals. Laboratory tests carried out by Dr Chui-Nan at the University of Texas in 1978, and by biochemists in France and Poland in 1992, do seem to show that wheatgrass extract has antimutagenic properties, and may help prevent cancer-causing agents from provoking cell mutations. But demonstrating a plant's property in the laboratory is a far cry from organising a scientific trial on humans; so far, rigorous research into the supposed superfood is thin on the ground.

What is more certain is the beneficial role all fresh fruit and vegetables play in protecting against common Western diseases such as heart problems and cancer: population studies have shown that people who eat a diet rich in plant-based foods are generally much healthier than those who don't, although no one is exactly sure why. Current thinking is that the protective effects of plant foods - known as phytoprotective factors - are unlikely to lie in their vitamin content alone, since experiments using vitamin supplements have often failed to provide the same effects. Other elements in fruit and vegetables are likely to come into play, and it may be that wheatgrass is particularly well endowed with those beneficial compounds.

Nevertheless, nutritionists are sceptical about the ability of any single food to act as a magic bullet. To function properly our bodies need to extract over 50 nutrients from our diet, and it is unlikely that any one source can provide the bulk of our requirements. They recommend we stick to tried and trusted advice: accept that there are no shortcuts to good health, eat a varied diet with plenty of fresh fruit and veg (at least five portions a day), and follow the usual caveats about smoking, alcohol and exercise.

If you've got money burning a hole in your pocket, wheatgrass certainly won't do you any harm, and might do you some good; but until more conclusive research is carried out, those of us on a tighter budget would probably be better off splashing our cash at the greengrocern