TABLE OF CONTENTS In addition to the nutrients listed above, food contains a vast complex of chemicals, many of which may have some nutritional or pharmaceutical value in certain circumstances. Given the variety and number of these chemicals, it is not surprising that some of them have been demonstrated to have effects in the body that can be shown to be beneficial. Many medical drugs are derived from plant sources in particular, and many plant foods are likely to contain chemicals that have some comparable effects. It is also likely that deficiency in one of them would normally not be noticed, because of the myriad of other components having a similar beneficial effect. In some cases, because of the wide distribution of a component, a deficiency would be unlikely to occur, without more severe under-nutrition or mal-nutrition becoming evident first. Often the presence of one component will have a sparing effect on another. This is seen with vitamins C and E and selenium, which have synergistic effects, although all are required individually for specific functions (Langseth, 1995). Many of these chemicals may have other significance in the food they may be flavour compounds, or give it colour, or act as natural antioxidants or preservatives. It would also be misleading to suggest that, because a certain food has a chemical that has been shown to be beneficial, significantly increased intake of that food will have a comparable beneficial effect. As has been emphasised previously, food comprises a very complex array of...
