Thursday, April 29, 2010

Tomato: top cancer-fighting food




On September 26, 1820, according to legend, a crowd of 2,000 fascinated people gathered in Salem, New Jersey, to watch Colonel Robert Gibbon Johnson commit suicide. At least that is what they expected, feared or wondered about as they watched Johnson, who stood on the steps of the town’s new courthouse. The fireman’s band played a mournful dirge. Colonel Robert Gibbon Johnson was about to eat a basket of tomatoes, and everyone knew that tomatoes are poisonous.
     Nothing happened, of course, when Gibbon ate his tomatoes. At least nothing adverse to Gibbon’s health. But that is said to be the start of a long journey to recognition of tomatoes as not only safe to eat, but very possibly the world’s healthiest food. We’ll talk, in a minute, about how to get the maximum benefits of the disease-fighting power of tomatoes.
     Whether the legend of Robert Gibbon is fact or fiction, what we do know is that Gibbon organized Salem County’s first agricultural and historical society in 1826; that tomato agriculture soon became a major industry in the area; that while it was already being eaten in some regions, in others it was still widely thought to be poisonous; and that the tomato history features a long journey, from South and Central America to Europe and across the Atlantic again to North America.
     The tomato is native to South America where it was grown and consumed in prehistoric times. By 500 BC it was being grown by the Aztecs in Mexico. It may have been brought to Europe as early as 1493 by Christopher Columbus, or by Spanish explorer Hernán Cortéz in 1521, after he captured Tenochtilan, the Aztec capital that is now Mexico City. It was in Europe no later than 1544 when Italian physician and botanist Pietro Andrea Mattioli called the tomato pomme d’oro, golden apple. Whoever it was that brought the first tomatoes or tomato seeds across the Atlantic must have brought yellow tomatoes. Some people though it was an aphrodisiac and called it pomme d’Amour, the love apple. Others called it the wolf apple.
     In 1597, English barber and surgeon John Gerard, in his book Gerard’s Herbal, classed tomatoes as poisonous. Gerard seems to have been at least partially responsible for a widely-held view in Britain and its North American colonies that the tomato was unfit to eat, if not actually poisonous—a view that was fairly widely held for more than two centuries.
     Spaniards and Italians were eating tomatoes anyway, possibly more than a hundred years before Gerard published his warning.  First known tomato recipes were included in a cookbook published in Florence, Italy in 1692, but in some parts of the Mediterranean tomatoes were still grown only as decorative plants.
     Spaniards brought the tomato back across the Atlantic to their Caribbean colonies, and from there they may have come to North America, where herbalist William Salmon reported seeing them in what is now South Carolina in 1710. Thomas Jefferson, who lived in Paris for five years, brought tomato seeds to his Virginia home in 1789 and planted them in his kitchen garden.

EAT TOMATOES EVERY DAY
     Skip a few centuries to January 21, 2002 and a feature in Time magazine, “10 Foods That Pack a Wallop,” in their disease-fighting ability and nutritional value. Top of the list were tomatoes. Others were spinach, red wine, nuts, broccoli, oats, salmon, garlic, green tea, and blueberries. “Eating tomato-based products every day should be a part of a healthy diet,” say researchers at The Prostate Centre, Princess Margaret Hospital, Canada’s leading cancer research hospital (Challenging Prostate: Nutrition, Exercise and You).
     Tomatoes are fat- and cholesterol-free and low in sodium. They are a very good source of dietary fibre, Vitamins, A, C, and K, potassium and manganese. They are also a good source of vitamins E and B6, thiamin, niacin, foliate magnesium, phosphorous and copper.
     Tomatoes are also the richest source of lycopene, a powerful antioxidant that helps fight free radicals, which are implicated in cancer, heart disease and macular degeneration. It is declared to be especially effective in fighting prostate, lung and stomach cancers. Tomatoes also contain a variety of protective phytonutrients.
     To get the full disease-fight power of tomatoes, they must been cooked, and better yet, cooked with a little canola or olive oil.  Cooking tomatoes “releases lycopene from inside the cells,” says the Prostate Centre. And because lycopene is fat-soluble, “Your body will absorb more when it’s processed with a little oil.”
     The effect of cooking and oil in releasing lycopene is dramatic. The Prostate Centre says that from one raw, medium-sized tomato (about 123 grams) you can get 3.2 mg of lycopene; from one cup of stewed tomatoes, 10.3 mg; from one cup of tomato juice 22 mg; and from just half a cup of pasta sauce, 21.5 mg.
     Tomato juice, soups, ketchup and sauces are thus ways to get the full benefits of tomatoes. But a word of warning: many of these tomato products are also very high in sodium. We’ll look at that in my next blog.

THE SYNERGY OF TOMATOES, BROCCOLI AND GREEN TEA
Here’s a way to get even greater health benefits from tomatoes: serve them with broccoli, or serve them with green tea. Tomatoes, broccoli and green tea are all rich in the disease-fighting lycopene, but serving them in combination delivers a more powerful punch than eating them at separate meals, according to an extensive article in The World’s Healthiest Foods. That’s synergy.
     The tomato and broccoli combination might be particularly applicable to prostate cancer. “When tomatoes and broccoli are eaten together, we see an additive effect,” says John Erdman, professor of food science and human nutrition at the University of Illinois and lead author of a study on the prostate effects on rats of tomato and broccoli diets. “We think it’s because different bioactive compounds in each food work on different anti-cancer pathways,” Erdman says.
     Care must be taken, however, in cooking broccoli. The phytonutrients in tomatoes become more concentrated when cooked, and more bioavailable when eaten with a little oil, while those in broccoli are greatly reduced with too much cooking. The World’s Healthiest Foods advises cutting broccoli florets in half or quarters and letting them stand for five minutes to allow the cancer-preventing compounds to form, then “Steam or healthy sauté broccoli no more than five minutes.”
     Another reported study suggests that the tomato and green tea combination might reduce the risk of prostate cancer as much as 86 percent.
     TAGS: Tomato history. Medicine.  Tomato juice. Lycopene. Phytonutrients. Cardiovascular disease. Cancer. Prostate cancer. Green tea. Broccoli. Antioxidants. Dietary fibre. Vitamins. Cholesterol. Sodium.