The decision by Asda, which is owned by US giant Wal-Mart, comes just a week after details were leaked to the UK press of a study by researchers at Southampton University for the Food Standards Agency, which concluded that several artificial additives increase the risk of hyperactivity and unruly behaviour in young children. The suspects reportedly include sunset yellow (E110), allura red AC (E129) and the preservative sodium benzoate. Asda has pledged to remove any artificial colours or flavours from its 9,000 own label products, as well as aspartame, hydrogenated fat and flavour enhancers such as monosodium glutamate. They will also meet the Food Standards Agency's salt reduction targets - two years ahead of the 2010 deadline. The supermarket is spending £30m (c €44m) on reformulation. It says that in the main, taste will be unaffected. Artificial flavours will be replaced by natural alternatives. Aspartame will be replaced by sucralose (described as "a sweetener made from sugar that tastes like sugar"). Aspartame has long been eyed with suspicion, even though the European Food Standards Authority last year reaffirmed its opinion that it is safe, in the light of the negative Ramazzini Foundation study linking it with cancer. As for colours, Asda is taking out the likes of carmine (E120), erythrosine (E127), quinoline (E104) and sulphate ammonia caramel (E150d). Where necessary these will be replaced by natural colours derived from fruit and vegetables - but in many cases the colours will simply be taken out and not replaced. Darren Blackhurt, Asda's food trading director, said: "We know that our customers, particularly those that are mums and dads, are becoming more and more concerned about what's in the food they buy." Indeed, consumer awareness of nutrition and food quality in the UK has soared in the last few years, a result some say has a lot to do with the high profile campaign led by celebrity chef Jamie Oliver over school meals. Many ingredients firms have already shored up their natural offerings to meet demand, and Asda's decision provides strong validation for the strategy. It also shows the power of the consumer in shaping the food industry: they tend to vote with their feet, and the UK food retailing scene is highly competitive. At the same time, retailers have tremendous clout over food manufacturers, calling the shots over what they will or will not stock on their shelves. Although Asda's reformulation relates only to its private label range, it could put pressure on other food manufacturers to take parallel action - especially since private label ranges often already have a cost advantage. According to a recent report from Datamonitor 36.7 per cent of consumer packaged goods (food, beverage and personal care) sold in the UK were private label in 2006, amounting to £42bn. The UK has the biggest private label market in Europe. Asda says it is the first UK supermarket to remove all artificial additives from its private label ranges. But others have taken some measures in the past. For instance, Marks and Spencer and Tesco have both previously published lists or rankings of ingredients to eliminate from its products.