Cancer is the second leading cause of death in the United States. It is estimated that diet may account for as much as 35% of all human cancers. Research shows that low antioxidant intake or low blood levels of antioxidants increases cancer risk. A low dietary intake of fruits and vegetables doubles the risk of most types of cancers.
The route from oxidants to cancer is simply as follows. An oxidant damages a strand of DNA. When the cell divides, the unrepaired DNA lesion can give rise to a mutation (Ames, et al, 1993). If a cell with a damaged (mutated) DNA strand divides, cell metabolism and duplication becomes abnormal, possibly leading to carcinogenesis. Oxidants may stimulate cell division, which is a critical factor in mutagenesis and cancer.
Antioxidants decrease oxidative damage to DNA and decrease abnormal increases in cell division (Ames, et al, 1993). In doing so they decrease mutagenesis, and thus carcinogenesis.
Two of the major causes of cancer are cigarette smoking and chronic inflammation. Smokers tend to have lower antioxidant levels than non-smokers and are at an increased risk for both cancer and cardiovascular disease. Epidemiological studies examining the relation between antioxidant levels and cigarette-induced lung cancer show that antioxidants have a significant protective effect.
The risk of cancer is significantly reduced through a diet high in vitamin C. Fruits and vegetables included in the diet have a significant impact on cancer risk. As well as the primary antioxidant activity that irresponsible for protection against tumorgenesis, other anticancer activities have been found in several plant-derived substances. Sulphur containing phytochemicals (e.g. allyl sulphides) of the allium family (garlic, onions, and leeks), and isothyocyanates and sulphoraphane (cabbage, broccoli, and cauliflower) inhibit various steps in tumour development. Other may protective compounds are indoles, found in cruciferous vegetables, and terpenes, natural constituents of citrus oils (Ames, et al, 1993).
Barley grass contains vitamin E succinate (VES), an analogue of alpha-tocopherol. VES potently inhibits the proliferation certain types of cancer cells (Johnson & Mokler, 2001).
The peels (skin) of a purple eggplant (bringal, aubergine, Solanum melongena) contains cancer fighting components. The skin gets it colour from a chemical called nasunin or more correctly delphinidin-3-(p-coumaroylrutinoside)-5-glucoside. Nasunin has been shown to have both antioxidant and antiangiogenic activities. In the field of cancer research, antiangiogenisis agents were heralded as a new way of preventing cancer cells from growing and spreading by stopping the development of new blood vessels. As a cancer grows, it needs new blood vessels close by to provide nutrients. When new blood vessels are prevented from developing, the cancer starves and dies.
The whole vegetable has also potential beneficial effects. Eggplant fruit juice exhibits an antimutagenic activity when tested in laboratory tests. It is suggested that there are multiple components that exist in the eggplant fruit including lutein that may be responsible.
There are reports of the effectiveness of eggplants in skin melanomas.
Melanoma is a malignant tumor of melanocytes which are found predominantly in skin but also in the bowel and the eye (see uveal melanoma). It is one of the rarer types of skin cancer but causes the majority of skin cancer related deaths. Malignant melanoma is a potentially serious type of skin cancer. It is due to uncontrolled growth of pigment cells, called melanocytes. Despite many years of intensive laboratory and clinical research, the sole effective cure is surgical resection of the primary tumor before it achieves a thickness greater than 1 mm.
Around 160,000 new cases of melanoma are diagnosed worldwide each year, and it is more frequent in males and Caucasians. It is more common in Caucasian populations living in sunny climates than other groups. According to the WHO Report about 48,000 melanoma related deaths occur worldwide per annum.