The tomato has baffled botanists since they started categorizing the plants in Mother Nature’s garden: is it a fruit or a vegetable? Even in the 21st century, the confusion continues—botanists define it as a fruit, while consumers call it a vegetable. Well, sometimes the tomato is neither—when it’s sun-dried. Then it’s a spice.
Tomatoes are officially “sun-dried” when all the moisture is taken out. At the same time, all the nutrients are left in—delivering a super-concentrated dose of the healthful vitamins, minerals, and phytochemicals for which the tomato is justifiably praised. The most notable of these is lycopene, the pigment that colors tomatoes red.
Lycopene is also the strongest member of the formidable family of antioxidants known as carotenoids. Antioxidants play a key role in human health because they help protect your body from the ravages ofreactive oxygen species (ROS), cell-damaging, disease-causing molecules created in excess by many features of modern life, such as air pollution, a sugary or fatty diet, and secondhand smoke.
Unlike some other nutrients, lycopene isn’t manufactured by the body. Food is our only source—and 85 percent of the lycopene in the diet comes from tomatoes and tomato products. And while it’s hard to beat the juicy taste of a red-ripe tomato plucked right from the summer vine, ounce for ounce you’ll get more disease-fighting lycopene from sun-dried tomatoes. When researchers tested a wide range of tomato products to find out which was tops in lycopene, sun-dried was the winner by a big margin. No surprise, considering it takes 10 tomatoes to produce one ounce of sun-dried tomato.
Prostate Cancer Protection
Lycopene first caught the attention of researchers nearly three decades ago when studies showed that death rates for all forms of cancers were lowest in older Americans who had the highest intake of tomatoes. But the nutrient really gained notoriety when studies started to show that it might help protect men against prostate cancer.
To date, dozens of studies have been conducted on tomato, lycopene, and prostate cancer. Results aren’t consistent, but many show that regular consumption of tomato-based foods can help prevent and treat the disease. For example:
In a report in Cancer Epidemiology, Biomarkers and Prevention, researchers analyzed 21 studies on tomato intake and prostate cancer. Men who had eaten the most cooked tomatoes had a 19 percent lower risk of prostate cancer, compared to men who had eaten the least.
In another study, men newly diagnosed with prostate cancer were put on a diet that included pasta dishes made with tomato sauce. After three weeks, their blood levels of PSA (prostate-specific antigen), a biomarker for prostate cancer activity, declined by 20 percent.
In India, scientists studied a group of men with life-threatening metastatic prostate cancer, in which the disease has spread outside the organ. Since testosterone fuels the growth of prostate cells, all the men had opted for medical treatment to reduce the hormone, but half also took lycopene supplements. Two years later, PSA levels were lowest in those taking lycopene.
More Anti-Cancer Power
Lycopene shows promise in reducing the risk of several other cancers.
Breast cancer. Cellular and animal studies show that lycopene helps kill breast cancer cells, even the types most resistant to cancer drugs.
Colon cancer. Researchers measured blood levels of lycopene in people with and without colorectal adenoma, an intestinal growth that can turn into cancer. Those with polyps had 35 percent less lycopene.
Brain cancer. A study in animals found that lycopene treatments inhibited the growth of malignant brain cancer (glioma) cells. Growth slowed even more when the animals were given lycopene before being injected with the cancer cells.
Pancreatic cancer. A study in the Journal of Nutrition found that those with the highest intake of lycopene had a 31 percent lower risk of pancreatic cancer.
Studies also have reported encouraging results for lycopene in battling cancers of the bladder, cervix, liver, lung, stomach, and blood.
Tomato may help prevent and/or treat:
Blood clots
Cancer
Cholesterol problems (high total cholesterol, high “bad” LDL cholesterol)
Dementia, non-
Alzheimer’s
Heart attack
Heart disease
High blood pressure (hypertension)
Infertility, male
Osteoporosis
Parkinson’s disease
Red Alert: Tomatoes Are Good for Your Heart
Tomato plants thrive in warm sandy soil, and some of the world’s best tomatoes are grown and dried in the exquisitely sun-drenched coastal regions along the Mediterranean Sea—where people eating the healthy foods (and sipping the red wine) of the Mediterranean diet enjoy a lower incidence of heart disease than people in the United States and many other countries. There’s a lot of debate over which foods or combination of foods in the Mediterranean diet are the cause of healthier hearts. But a new study in the British Medical Journal shows that high vegetable consumption is right up there—including the lycopene-rich tomato.
In one study on lycopene and heart disease, researchers looked at the dietary intakes of 1,400 people, half of whom had suffered a heart attack. Focusing on three powerful antioxidants—vitamin E, beta carotene, and lycopene—they found that only lycopene was linked to a lower rate of heart attacks. Lycopene may play a role in the protective effect of vegetable consumption on heart attack risk, concluded the researchers in the American Journal of Epidemiology.
In another study, Harvard researchers tracked the tomato consumption of nearly 40,000 middle age and older women with no known heart disease. After seven years, those who had eaten only 1½ or fewer servings a week of lycopene-rich tomato products had a 29 percent higher risk of developing cardiovascular disease than those eating 7 to 10 weekly servings.
The Poisonous TomatoThey say it was a brave man who first tasted an oyster, but perhaps that distinction should go to the first person to bite into a tomato. Tomato plants were around for a century or so before tomatoes found their way into European kitchens—people resisted the tempting red ball of flavor because they feared it was poisonous.
When tomato seeds first landed in Europe via Spain in the mid-16th century, people were shocked to find that it was kin to a plant with a deadly reputation: belladonna, the most notorious member of the nightshade family of plants. According to food historians, there is no evidence the tomato was eaten or used in cooking for over 100 years after its arrival in Europe. The first mention of tomatoes in a recipe did not appear in any continental cookbooks until the mid-1700s, and it took another 50 years until it became common.
How the tomato eventually overcame this misconception is unclear, but it might have had something to do with its fabled reputation for being an aphrodisiac. Perhaps like Adam, a curious person couldn’t resist it. Hence, its 18th-century moniker: love apple.
By the way, early fear-mongers were not totally wrong. The leaves of the tomato plant do contain a poisonous alkaloid. In small doses, it’s not strong enough to harm people, but could sicken a dog or cat. In fact, some cooks add a tomato leaf or two at the end of making a tomato sauce to restore some of the fresh taste lost in cooking.
Studies show that lycopene helps keep the heart strong and arteries flexible in three ways: by blocking the formation of “bad” LDL cholesterol, by thinning blood, and by lowering high blood pressure.
In a study reported in The British Journal of Nutrition, 21 healthy people spent three weeks eating a diet loaded with lycopene, with a daily intake of two cups of tomato juice and one ounce of ketchup. After three weeks, their LDL had dropped by 13 percent and their total cholesterol by 6 percent. The researchers also found that the tomato-rich diet cut the oxidation of LDL, reducing its ability to turn into artery-clogging plaque.
Researchers from Scotland found that a tomato extract (a pill equal to six whole tomatoes) reduced the ability of blood to clot—a risk factor for a heart attack—by 72 percent.
As for high blood pressure, researchers in Israel asked 54 people with high blood pressure that wasn’t controlled by medication (an ACE inhibitor, calcium channel blocker, or diuretic) to also take either a tomato extract or a placebo. After six weeks, those taking the tomato extract had a “clinically significant” drop in blood pressure—systolic blood pressure fell from an average of 146 to 132, and diastolic blood pressure from 82 to 78. At the same time, their blood levels of lycopene tripled. In those taking the placebo, there was no change in lycopene levels or blood pressure.
Bone Up on Lycopene
More than 10 million Americans have the bone-weakening disease osteoporosis—approximately 15 percent of women and 4 percent of men over the age of 50. Another 10 million or so have osteopenia—bone density that is below normal and may lead to osteoporosis. And every year, two million people with osteoporosis have a so-called “osteoporotic fracture,” usually of the hip, spine, or wrist.
You might want to throw some tomatoes at poorly performing bones. Cellular studies from researchers in the Department of Nutritional Sciences at the University of Toronto showed that lycopene might play a role in bone-building—stimulating osteoblasts (the cells that add to bone) and blocking osteoclasts (the cells that destroy bone). “Our research suggests that prevention and treatment of osteoporosis through the consumption of tomatoes and tomato products rich in lycopene may offer a viable alternative to medication for osteoporosis,” said Leticia Rao, PhD, one of the researchers.
Those same researchers also say that ROS might spur the development of osteoporosis, just as they do heart disease. In a study on postmenopausal women (the main victims of osteoporosis), the Canadian researchers found the women with a lycopene-rich diet had much lower levels of a biomarker linked to high levels of ROS and bone destruction. “These results suggest that the dietary antioxidant lycopene reduces oxidative stress and the levels of bone turnover markers in postmenopausal women, and may be beneficial in reducing the risk of osteoporosis,” wrote the researchers in Osteoporosis International.
The Brain-Lycopene Connection
Several studies show that lycopene may play a role in dementia, Parkinson’s disease, and other forms of age-related decline. For example:
Tomatoes are at their tastiest when allowed to fully ripen on the summer vine.Low blood levels of lycopene levels were found in people with vascular dementia (the second most common kind, after Alzheimer’s) and with Parkinson’s disease. And in a study of 88 elderly nuns in a nursing home, researchers linked higher blood levels of lycopene with an improved ability to perform self-care tasks.
Researchers speculate that lycopene might protect the brain by reducing damage from ROS.
Male Fertility Pill
An estimated 7 to 10 percent of men in their prime reproductive years (age 20 to 50) are infertile. In one out of four of those men, doctors can’t find a cause. It could be ROS—studies show that 25 percent of men with unexplained infertility have significant levels of ROS in their semen, whereas fertile men have no detectable levels. Could lycopene help?
Researchers in India studied 50 infertile men between the ages of 21 and 50, treating them with eight milligrams (mg) of lycopene a day for one year. On average, the men had significant improvements in sperm quality—and 36 percent of their partners went on to have successful pregnancies.
Is It Tomatoes or Lycopene?
Lycopene may be the tomato’s crown jewel, but the fruit contains other nutritional gems. Tomatoes are also rich in vitamin C. And they’re loaded with plant compounds (phytochemicals) such as coumaric acid, chlorogenic acid, and tomatine, all of which have anti-disease activity.
Many lycopene studies used tomato products as the source of the nutrient. This means lycopene may not act alone. Rather, it may derive its disease-fighting strength from working with other nutrients.
So even though lycopene is available as a dietary supplement, I don’t recommend it. In my view, your best bet is to eat more tomatoes and tomato-containing foods such as tomato sauces, soups, juices, and ketchup—and always have a jar of sun-dried tomatoes in your refrigerator. In fact, it’s a good idea to eat sun-dried tomatoes and other tomato products daily. When you stop eating tomatoes, lycopene levels plummet.
The Whole World Loves Tomatoes
The tomato is used in virtually every cuisine in the world to flavor just about every food. The total number of dishes in which tomato is the main ingredient numbers in the thousands.
Needless to say, Italian cuisine would be a lot less appealing if it weren’t for the tomato. The tomato is also a staple in the Indian diet—it’s frequently used as the liquid that balances the spices in curries and is a common ingredient in chutneys. Tomato is the ingredient that adds a sweet acidic flavor to many dishes in Southeast Asia, and the Chinese use tomato in sweet-and-sour sauces. It’s the main ingredient in vegetable-spice mixes such as Latin American and Mexican salsas, Indonesian sambals, and Spanish sofritos.
Currywurst—a sausage topped with a tomato sauce spiked with curry powder and paprika—is a national dish in Germany. (It’s sold on street corners in Berlin just like hot dogs are sold on the streets of Manhattan.) The French slow roast tomato into a confit as a rich full-bodied flavor enhancer. In Spanish Catalonia, people rub tomato into grilled bread for a snack called scrubbed toast. The tomato has even generated its share of geographical controversy: New Englanders were up in arms when New Yorkers replaced the cream in their famed clam chowder with tomato and renamed it Manhattan clam chowder.
Tomatoes are grown fresh in numerous colors and sizes—there are green, yellow, orange, red, and purple tomatoes, and varieties ranging from the size of a grape to a baseball.
Tomatoes are at their tastiest—and most health-giving—when allowed to fully ripen on the summer vine. Lycopene gives tomatoes their rich, red hue, and the pigment saturates the tomato only when it’s vine-ripened.
As for taste: while tomatoes contain gel-like substances that makes them juicy, the flavor comes from the wall, the flesh just inside the skin. That flavor intensifies as sugar and acids build up during ripening. So it’s no wonder that supermarket tomatoes are derided as “flavorless produce”—they’re picked and shipped when they’re still green and then exposed to ethylene gas, which triggers ripening in mature fruit.
TOMATOES CAN BE DRIED IN AN HOUR OR TWO WITH A FOOD DEHYDRATOR.My recommendation: unless you grow your own tomatoes, or can buy local tomatoes at a farmer’s market, use canned or jarred tomatoes. They’re actually healthier. Studies show that lycopene is much better absorbed from cooked tomatoes. One study showed triple the absorption after a tomato product was heated. In another, the lycopene in tomato paste was nearly four times better absorbed than that from fresh tomatoes.
The variety of tomato products is almost endless. There are an infinite number of soups, juices, sauces, pastes, and stews. Cooked tomatoes come whole, diced, crushed, stewed, pureed—and, of course, as a sun-dried spice.
Getting to Know Sun-Dried Tomato
Sun-dried tomatoes have probably been around since, well, since tomatoes. They’re a staple of Mediterranean and Italian diets—traditionally, Italian families put some of their tomato crop on the rooftop to dry, so they’d have enough tomatoes to last through winter and into the next growing season. Recently, they’ve become popular in the US—some estimates say that more are consumed here than in Italy!
Sun-dried tomatoes are so named because they’re left to bask in the sun day after day until they shrivel up and dry. This can take anywhere from 4 to 14 days. The process isn’t difficult, but it requires just the right environment. The tomatoes need good ventilation, protection from critters, and have to be brought in at night. If you’re planning to dry tomatoes yourself, it requires a lot of patience. Remember, too, that it takes a lot of fresh tomato to make a little sun-dried. A baseball-size tomato will shrink to the size of a pinky ring.
Their intense flavor, and the painstaking process of producing them, classifies them as gourmet items—with a price to match. A small eight-ounce jar—available at most supermarkets and gourmet stores—can cost six dollars or more. Compare that to the 60 cents you pay for the same sized can of tomato sauce.
There is, however, a relatively easy way to dry a tomato, without ever exposing it to the sun: slow roasting. You can use any type of ripe tomato, though the Roma is considered best because it has fewer seeds than other varieties. Here’s how to do it:
1. Cut the stem end out of each tomato and slice the tomatoes in half lengthwise. Line the tomato halves up on a pastry sheet, making sure that they do not touch, and sprinkle them with salt and your favorite spices.
2. Put them in a pre-heated 200°F oven and leave them there for the next 8 to 10 hours. Check them every hour or so. They are done when they are dry with no sign of moisture. They may not all bake uniformly—and if the tomato isn’t fully dried, the remaining moisture can collect bacteria. So, if necessary, remove them from the oven one by one, as they finish.
Another way to dry them is with a food dehydrator. A drawback is the initial expense of the dehydrator, which can cost $150 or more. But the advantage is that the tomatoes dry in an hour or two. Look for a device with a temperature gauge (maintaining the right temperature while drying keeps bacteria at bay) and follow the manufacturer’s directions.
Oven-Roasted TomatoesLong before there were sun-dried tomatoes, the French were capturing the concentrated goodness of the fruit by making a confit.
The method for making tomato confit is similar to sun-dried tomatoes, except the tomatoes are taken out of the oven when they are still soft. They are then jarred, to use in salads, on pasta, or in anything that would be enhanced by a rich, pure tomato flavor.
To make tomato confit, quarter whole tomatoes and put them on a baking sheet lined with tinfoil. Sprinkle them with salt, pepper, dried thyme, and a little confectioner’s sugar. Place a garlic sliver in the middle of each tomato and bake in a 200°F oven for an hour. Turn, baste, and bake for another hour.
You can keep dehydrated tomatoes in plastic freezer bags. They’ll keep in a cool, dry place for about two months or in the freezer for six to nine months. Before storing, make sure all the air is squeezed out.
As for oven-dried tomatoes: once properly dried (meaning totally dried), you can pack them in an airtight container and keep them in the pantry indefinitely. (You will have to reconstitute them before using.) Or you can also pack them in a jar with olive oil, where they will keep refrigerated for about two weeks.
To reconstitute sun-dried tomatoes, put them in warm water for about 30 minutes. If you reconstitute sun-dried tomatoes but don’t use them right away, you must refrigerate them.
Here are some ways to enjoy sun-dried tomatoes:
• Eat them as a luscious snack.
• Stir them into soups, stews, and sauces just before serving, to give the dishes a rich color.
• Use them in place of fresh tomatoes in sandwiches.
• Chop and add to tuna, chicken, or green salads.
• Slice and serve them in pasta dishes.
In the Kitchen with Tomato
Tomatoes originated in South America and fresh tomatoes don’t take kindly to cold. Keep them out of the refrigerator, which chills the taste right out of them. Instead, keep them in a cool place—their ideal temperature is 55°F. And keep them out of the sun.
If for some reason you refrigerate fresh tomatoes, let them sit at room temperature for at least a half hour before eating. You’ll get back most (but not all) of the flavor.
Tomatoes yield to slight pressure when ripe. If you buy tomatoes that aren’t quite ripe, you can hasten the ripening process by putting them in a brown paper bag with a banana, which releases ethylene gas.
Here are some other ways to optimize the flavor and nutrition of tomatoes:
Go for gazpacho. This raw, tomato-based soup is good for you. Researchers at Tufts University asked a group of volunteers to eat gazpacho twice a day for a week. Their blood levels of vitamin C went up an average of 25 percent and their levels of three biomarkers for inflammation (a risk factor for heart disease) went down.
Whole is better. Whether fresh or canned, favor whole tomatoes. Studies show they’re nutritionally superior to skinned-and-seeded varieties. (Don’t remove the seeds and juice from fresh tomatoes unless the recipe calls for it—doing so changes the flavor balance in favor of sweetness.)
Strike oil. Tomatoes and olive oil are the mainstays of the Mediterranean diet—and they team up to beat disease, because olive oil increases the body’s ability to absorb lycopene. When Harvard researchers analyzed the diets of 40,000 women, they found the highest lycopene levels in women who ate foods with tomatoes and olive oil (that includes pizza!). Those women had a 34 percent reduced risk of heart disease, compared to 29 percent for tomato-lovers who didn’t routinely add oil to their tomato-based meals. So don’t be shy—pour on the olive oil.
Tomato pairs well with virtually all spices, but particularly well with:
Basil
Chile
Fennel seed
Garlic
Onion
Oregano
Parsley
Rosemary
Thyme
and complements recipes featuring:
Beef
Chicken
Cheese (feta,
Parmesan, ricotta,
Romano)
Corn pie
Eggs
Green beans
Pasta
Poultry
Sandwiches
Shrimp
Soups
Stews
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Other recipes containing tomato:
All-American Chili con Carne
Bloody Mary Soup with Jumbo Lump Crabmeat
Boeuf Bourguignon
Brussels Sprouts Kulambu
By-the-Bay Fisherman’s Chowder
Hungarian Goulash
Madras Beef Curry
Mussels with Thai Red Curry Sauce
Onion and Tomato Chutney
Penne and Sausage with Fennel Tomato Sauce
Potato Cauliflower Curry
Prawns with Almond Hot Pepper Sauce
Spaghettini with Basil-Tomato Sauce
Roasted Tomato Soup with Fennel and MintThe tomatoes in this soup are slow roasted to produce concentrated flavor in the same way you make sun-dried tomatoes. You just take them out of the oven a lot sooner. The soup can be served warm or chilled. It makes a nice dinner starter or a light lunch with a salad. You can also stir in cooked crab. To dress it up, place a butterflied shrimp in the center of the soup and top with a dollop of sour cream or guacamole.
2 pounds tomatoes
Sea salt
2 teaspoons dried mint
2 teaspoons dried oregano
2 teaspoons dried parsley
2 teaspoons dried thyme
1 teaspoon fennel seeds
3 cups chicken stock
Fresh mint sprigs, for garnish
1. Cut the stem end out of the tomatoes. Slice the tomatoes in half and place them on a pastry sheet lined with tin foil. Sprinkle with sea salt.
2. Combine the mint, oregano, parsley, and thyme in a dish. Separate out 1 teaspoon of the mixed herbs and set aside. Sprinkle the larger portion of the spices on top of the tomatoes. Put in a preheated 275°F oven for 3 hours or until the tomatoes give off all their juices. Remove from the oven and cool.
3. Meanwhile, dry roast the fennel seeds. Heat a small heavy skillet and add the seeds, shaking the pan so they do not burn until they emit an aroma and darken. Set aside to cool.
4. Put the chicken stock in a medium saucepan and heat to a simmer. Remove from the stove. Put the roasted tomatoes in the bowl of a food processor. Add the fennel seeds, the rest of the spice mixture, and the chicken broth and process until smooth. Return to the saucepan and heat. Serve garnished with mint sprigs.
Serves 6 as a starter and 4 as a main course.Team up tomato with broccoli. As a member of the cruciferous family of vegetables, broccoli is a well-known cancer fighter. In animal research at the University of Illinois, scientists found that broccoli and tomato together more effectively reduced the risk of prostate cancer than either one alone.
Here are some other tips for working with tomatoes in the kitchen:
• Take advantage of tomatoes in season (and get more lycopene!) by buying in bulk and making large batches of sauces. Freeze the sauce in small containers for ease of use.
• Perk up commercial pasta sauce by adding a cup or two of canned chopped tomatoes while it is cooking.
• Enhance the taste and healing power of tomato dishes by sprinkling them with baharat, a popular Middle Eastern spice mix. You’ll find a recipe for the mix on Baharat.
• When making a puree from scratch, you’ll get a smoother sauce by starting with fresh tomatoes or canned crushed rather than whole canned tomatoes. This is because canners frequently add calcium salts to whole canned tomatoes to help keep the cell walls intact. This interferes with the disintegration during cooking. If you want to make a fine-textured dish using canned tomatoes, check the labels and look for a brand that doesn’t list calcium among the ingredients.
• Adding a little sugar to tomato sauce as it’s cooking intensifies the flavor.
• Make a fast and tasty barbecue sauce by combining 1 cup of ketchup with a few cloves of diced garlic, 2 tablespoons of diced ginger, 2 tablespoons of rum, and ¼ cup each of brown sugar, soy sauce, and distilled white vinegar.
• Pan roast tomatoes by cutting them in half and putting them in a pan of hot olive oil. Puncture the sides of the tomatoes with a sharp knife, so the liquid seeps out. Cook for 10 minutes, turn, sprinkle with salt and spices and cook another 10 minutes.
• Here’s how to make scrubbed toast, a classic favorite in the Catalonian region of Spain. Grill or broil thick crusty bread. While it’s still hot, rub the bread with a crushed garlic clove. Cut a large tomato in half and scrub it into the bread until it absorbs the juices and the seeds coat the bread.
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