Summary Phytic acid present in cereals, legumes and oilseeds is usually regarded as an anti-nutritive factor. Its negative effects on the bioavailabilty of iron and other essential minerals and trace elements have been described in several studies in man and monogastric animals. Phytic acid and iron are thought to form insoluble complexes which are not available for absorption under the pH conditions of the small intestine. A number of recent studies have suggested that reducing the phytate content of foods by genetic modification or via the action of intrinsic or extrinsic phytases may have a beneficial impact on iron availability. Over the last decade potential beneficial effects of phytic acid have also been recognized. In vitro studies indicate that phytic acid acts as an anti-oxidant through its iron chelating properties. However, it is as yet uncertain whether physiological intakes of phytic acid can significantly improve the anti-oxidant status in man and animals.