College London, said the research did show some differences. “But the question is are they within natural variation? And are they nutritionally relevant? I am not convinced.” He said Leifert’s work had caused controversy in the past. “Leifert has had a lot of disagreements with a lot of people.” Sanders added the research showed organic cereals have less protein than conventional crops. The results of the research are based on an analysis of 343 peer-reviewed studies from around the world – more than ever before – which examine differences between organic and conventional fruit, vegetables and cereals. “The crucially important thing about this research is that it shatters the myth that how we farm does not affect the quality of the food we eat,” said Helen Browning, chief executive of the Soil Association, which campaigns for organic farming. Plants produce many of their antioxidant compounds to fight back against pest attacks, so the higher levels in organic crops may result from their lack of protection by chemical sprays. But, the scientists say other reasons may be important, such as organic varieties being bred for toughness and not being overfed with artificial fertilizers. Leifert and his colleagues conclude that many antioxidants “have previously been linked to a reduced risk of chronic diseases, including cardiovascular diseases,