Immune-boosting Food: Tomatoes

Need more proof of the healing power of food? Look no further than the humble tomato, which has earned more high scores than any other menu item in studies of cancer-fighting foods. Along with a rich supply of vitamin C, tomatoes are loaded with lycopene. This powerful antioxidant gives them their luscious red colour and it has been convincingly shown to defend the body against cancer. Tomatoes are second only to carrots as a source of beta-carotene, a member of the carotenoid family of phytochemicals (see page 48).They are also excellent sources of the flavonoids quercetin and kaempferol, which inhibit the growth of cancer cells.

The proof: In a review of 72 studies published in the American Journal of the National Cancer Institute, researcher Edward Giovannucci, MD, of the Harvard Medical School, concluded that eating tomatoes and tomato-based products consistently led to higher levels of lycopene in the blood and a lower risk of a variety of cancers. In earlier research, Dr Giovannucci found that the risk of prostate cancer was a third lower in men who consumed tomato products, such as pasta sauce, at least twice a week.

Women reap benefits from lycopene, too. When researchers measured lycopene levels in breast-tissue samples from 109 women, those with higher levels of the nutrient were found to be less likely to develop breast cancer. More direct cancer-fighting benefits came to light when researchers at the University of Milan, Italy, put healthy young women on a tomato-free diet for three weeks, followed by three weeks of a tomato-rich diet. The results were startling. On the tomato-rich diet, the levels of lycopene in the women's blood increased, while the free-radical damage to the DNA in their lymph cells dropped by about 33 per cent.

Put tomatoes to work: Because lycopene is fat-soluble, it is more accessible to the body when the foods that contain it are prepared and eaten with a small amount of fat. In other words, pizza slathered with tomato sauce is preferable to tomatoes sliced raw and tossed in a salad.

Do you find that hard to believe? In one study, volunteers ate either a mock pizza made of bread, tomato paste and corn oil or a pile of fresh tomato slices without oil. Several hours after the meal, the pizza eaters' blood levels of lycopene were two and a half times higher than those of the salad eaters.

Similarly, when researchers at the University of California put patients with prostate cancer on a high-fibre diet that included small amounts of fat and 200 ml of tomato-vegetable juice a day, they detected a 'highly significant increase' of lycopene and other phytochemicals in the patients' blood. In a major European study, lycopene was shown also to lower the risk of heart attack. Its protective effect was found to be especially beneficial to nonsmokers.

1 comments:

Anonymous said...

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