Organically grown food crops are up to 70% richer in key antioxidants than their conventional counterparts, a study has found.
Researchers found that switching to an organic diet would provide an antioxidant boost equivalent to one to two extra portions of fruit and vegetables a day.
The study, published in the British Journal of Nutrition, also found significantly lower quantities of harmful heavy metals in organic crops.
Levels of highly toxic cadmium, which are restricted by the European Commission, were reduced by almost 50% compared with conventionally grown plants.
Professor Carlo Leifert, who led the research, said: "This study demonstrates that choosing food produced according to organic standards can lead to increased intake of nutritionally desirable antioxidants and reduced exposure to toxic heavy metals.
"This constitutes an important addition to the information currently available to consumers which until now has been confusing and in many cases is conflicting."