آنتی اکسیدان ها در میوه ها و سبزیجات – بهداشت هزاره Antioxidants in fruits and vegetables ± the millennium’s health

In recent years human health has assumed an unprecedentedly important status. Increased interests in nutrition, ®tness and beauty have exaggerated concerns over diet and human health. A new diet-health paradigm is evolving which places more emphasis on the positive aspects of diet. Foods have now assumed the status of `functional’ foods, which should be capable of providing additional physiological bene®t, such as preventing or delaying onset of chronic diseases, as well as meeting basic nutritional requirements. Nutritional studies are now concentrating on examining foods for their protective and disease preventing potential (Nicoli et al., 1999) instead of negative attributes such as micro-organism count, adulterants, fatty acids and inorganic pollutant concentration. Recently phytochemicals in fruits and vegetables have attracted a great deal of attention mainly concentrated on their role in preventing diseases caused as a result of oxidative stress. Oxidative stress, which releases free oxygen radicals in the body, has been implicated in a number of disorders including cardiovascular malfunction, cataracts, cancers, rheumatism and many other auto-immune diseases besides ageing. These phytochemicals act as antioxidants, scavenge free radicals and act as saviours of the cell. Epidemiological studies have consistently shown that there is a clear signi®cant positive associations between intake of fruits and vegetables and reduced rate of heart diseases mortality, common cancers and other degenerative diseases as well as ageing (Steinmetz & Potter, 1996; Garcia-Closas et al., 1999; Joseph et al., 1999; Dillard & German, 2000; Prior & Cao, 2000; Wargovich, 2000). The strongest evidence is related to reduced risk of cancers of the mouth and pharynx, oesophagus, lung, stomach and colon. The available data also gives strong support to a protective role for fruits and vegetables in protection against pancreas, bladder and breast cancer (American Institute of Cancer Research., 1997). This is attributed to the fact that these foods may provide an optimal mix of phytochemicals such as natural antioxidants, ®bres and other biotic compounds.