Sales of organic food in Britain could increase tenfold within the next 10 years, from 1 percent of all food eaten in the country to 10 percent, Carlo Leifert, director of the Organic Support Centre at Aberdeen University, said yesterday. His prediction comes as British supermarkets are starting a price war aimed at lowering the prices of some organic foods almost to the level of foods grown using pesticides. The Iceland supermarket chain was the first to pledge lower prices on organics, and Tesco, Britain’s largest supermarket company, announced this week that it will follow suit. The Sainsbury’s chain, meanwhile, has encouraged the entire Caribbean island of Grenada to convert to organic farming and has promised to buy as much organic food as it can produce. Tesco Marketing Director Tim Mason: “Demand is going through the roof, and this year will be remembered as the time when organic became mainstream.”