Over half of Irish consumers say they have never bought organic food, mostly because they believe it is too dear, according to research by the Food Safety Authority of Ireland (FSAI).
The authority's chief specialist in public health nutrition, Dr Mary Flynn, said yesterday there was little evidence to show that organic foods conferred health benefits on humans.
She was speaking at an open meeting on organic food organised by the FSAI's consultative council, at which more than 100 people debated the issue.
Dr Flynn described claims that organic food could boost a person's immune system as "woolly" and said the quality of much research in the area was not good enough and was often confounded by other factors. While acknowledging that consumers seemed happy to pay more for organic food, she warned producers to "rely on science" when making claims, otherwise they could be "on thin ice" when new EU regulations on health claims for foods are introduced.
The market for organic foods is growing rapidly - worth €66 million last year, up from €38 million in 2003 - as consumers respond to health scares and seek a healthier diet. However, claims about their nutritional and health benefits remain hotly disputed.
Plant scientist Dr Con O'Rourke said there was not yet a body of scientific evidence to show that organic food was significantly or consistently better than food produced using pesticides. A person eating a varied diet with lots of vegetables had no need for "superfoods" or organic produce, he suggested.
Dr O'Rourke acknowledged that organic food may contain higher levels of antioxidants and said organic farming created more biodiversity, but he said that staple Irish foods produced by conventional means were safe. He claimed supporters of organic food had a "hidden agenda" in opposing genetically modified food because if pest-resistant strains were developed using this technology, this would "steal the clothes" of organic growers.
Siobhán Morris, an organic food consultant, said the broad range of benefits organic farming could deliver needed to be taken into account. Organic food tended to be in season, harvested recently and involved plant varieties grown for taste.