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When buying tomatoes, choose those that smell like tomatoes; unripe ones have no scent.
Although they are used as vegetables, tomatoes are actually fruits, and are members of the nightshade family of plants. They come from Central and South America. Spanish explorers took them back to Europe and they eventually found their way back to North America.
There are hundreds of varieties of tomatoes, including large “beefsteak” types that are especially good for salads and for slicing on sandwiches; Italian plum tomatoes, called Roma tomatoes, which are ideal for cooked dishes like tomato sauce; and small, sweet cherry tomatoes. While red tomatoes are most common, these vegetables can also be yellow, green, pink, or orange.
Tomatoes are available fresh, and in a variety of canned products, such as stewed tomatoes, whole tomatoes, tomato sauce, tomato purée, and diced tomatoes. Tomatoes can also be dried and are sometimes packed in oil this way. Tomatoes are often juiced and can be concentrated to produce tomato paste.
Tomatoes are available year-round, but their flavour is far superior in mid- to late-summer. In winter and spring, cherry tomatoes tend to have the best flavour of all the varieties. Canned tomatoes are always available and, for cooked dishes, they are the best choice in the winter.
Tomatoes should be rinsed thoroughly before preparation. If they are being used to make tomato sauce for spaghetti or other dishes, they should be peeled and seeded. To peel a tomato, drop it into boiling water for one to two minutes. Then remove and dunk briefly in a bowl of ice water. Cut out a small cone around the stem end and slip off the skin. To seed a tomato, cut it in half horizontally and squeeze the seeds out.
Raw fresh tomatoes are most often sliced onto sandwiches or eaten in salads. They can also be cooked with herbs, onions, and garlic to make homemade spaghetti sauce. Raw tomatoes can be diced and added to soups or stews. Halved tomatoes can also be broiled. Place them on a baking sheet, drizzle with olive oil, and broil until the tops are lightly browned, about five minutes. Tomatoes make an attractive dish when stuffed with crabmeat or with sautéed vegetables, such as spinach and mushrooms, and baked.
Unripe, green tomatoes are often dipped in cornmeal and fried.
Canned tomatoes can be added to soups, stews, or bean dishes, or used to make spaghetti sauce. Combined with vegetable broth, they make a good base for many kinds of soups. Canned tomatoes can be puréed with soft tofu and then thinned with milk, soya milk, or broth, flavored with herbs, and heated to make a fast cream of tomato soup. Canned tomato sauce can also be used in curry dishes and to make chilli.
Never add canned tomatoes to uncooked beans or grains, since they toughen the skins of these foods, making it difficult to cook them to a tender stage.
Unless they are packed in oil, dried tomatoes (sometimes called sun-dried tomatoes) must first be slightly rehydrated by allowing them to soak in hot water. Dried tomatoes can be chopped and tossed with pasta or vegetable dishes. They can also be puréed with olive oil, toasted pine nuts, and basil to make tomato pesto.
Tomato, 1 medium whole (raw, ripe)
Calories: 26
Protein: 1.04g
Carbohydrate: 5.7g
Total Fat: 0.406g
Fiber: 1.35g
*Excellent source of: Vitamin C (23.5mg)
*Good source of: Vitamin A (766 IU)
*Foods that are an “excellent source” of a particular nutrient provide 20% or more of the Recommended Daily Value, based upon United States Department of Agriculture (USDA) guidelines. Foods that are a “good source” of a particular nutrient provide between 10 and 20% of the USDA Recommended Daily Value. Nutritional information and daily nutritional guidelines may vary in different countries. Please consult the appropriate organization in your country for specific nutritional values and the recommended daily guidelines.
Vitamin C, present in fruits and vegetables, is a powerful antioxidant and anti-inflammatory. This anti-inflammatory activity may influence the development of asthma symptoms. A large preliminary study has shown that young children with asthma experience significantly less wheezing if they eat a diet high in fruits rich in vitamin C.
Many Americans eat insufficient amounts of foods containing vitamin C; the disease caused by vitamin C deficiency, scurvy, causes easy bruising. While very few people actually have scurvy, even minor deficiencies of vitamin C can increase the incidence of bruising. People who experience easy bruising may want to try eating more fruits and vegetables—common dietary sources of vitamin C.
Tomatoes contain lycopene—an antioxidant similar in structure to beta-carotene. Most of the lycopene in our diet comes from tomatoes, though traces of lycopene exist in other foods. Lycopene inhibits the proliferation of cancer cells in test tube research.
A review of published research found that higher intake of tomatoes or higher blood levels of lycopene correlated with protection from cancer in 57 of 72 studies. Findings in 35 of these studies were statistically significant. Evidence of a protective effect for tomato consumption was strongest for cancers of the prostate, lung, and stomach, but some evidence of a protective effect also appeared for cancers of the pancreas, colon, rectum, oesophagus (throat), mouth, breast, and cervix. Many doctors recommend that people who are not allergic to tomatoes increase their intake to reduce their risk of cancer.
Tomatoes are also a source of beta-carotene. The strong association between increased intake of beta-carotene from food and a reduced risk of lung cancer does not necessarily mean that supplementation with natural beta-carotene supplements would reduce the risk of lung cancer. Dietary beta-carotene may be a marker for diets high in certain fruits and vegetables that contain other anticancer substances that may be responsible for the protective effects. Until more is known, some doctors advise smokers to avoid all forms of beta-carotene supplementation—even natural beta-carotene.
Eating plenty of flavonoid- and vitamin C-rich fruits and vegetables helps to support the structure of capillaries.
Some, but not all, studies have reported that eating more foods rich in beta-carotene or vitamin A was associated with a lower risk of cataracts. Synthetic beta-carotene supplementation has not been found to reduce the risk of cataract formation. It remains unclear whether natural beta-carotene from food or supplements would protect the eye or whether beta-carotene in food is merely a marker for other protective factors in fruits and vegetables high in beta-carotene.
A controlled trial showed that eating a diet high in fruits and vegetables containing folic acid, beta-carotene, and vitamin C effectively lowered homocysteine levels. Healthy people were assigned to either a diet containing a pound of fruits and vegetables per day, or to a diet containing 3 1/2 ounces (99g) of fruits and vegetables per day. After four weeks, those eating the higher amount of fruits and vegetables had an 11 percent lower homocysteine level compared to those eating the lower amount of fruits and vegetables.
People who eat plenty of fruits and vegetables high in beta-carotene appear to be at lower risk for macular degeneration than people who do not eat these foods. However, another study found no association between age-related macular degeneration and intake of antioxidants, either from the diet, from supplements, or from both combined. More research is needed to reconcile these differences. In the meantime, beta-carotene-rich vegetables continue to be part of a healthful diet.
Multiple sclerosis (MS)
In one survey, researchers gathered information from nearly 400 people (half with MS) over three years. They found that consumption of vegetable protein, fruit juice, and foods rich in vitamin C, thiamine, riboflavin, calcium, and potassium correlated with a decreased MS risk.
Low intake of fruits and vegetables containing beta-carotene, which the body can convert into vitamin A, may contribute to a vitamin A deficiency.
Osteoarthritis (OA)
Solanine is a substance found in nightshade plants, including tomatoes, white potatoes, all peppers (except black pepper), and eggplant. In theory, if it is not destroyed in the intestine, solanine could be toxic. A horticulturist, Dr. Norman Childers, hypothesized that some people with OA may not be able to destroy solanine in the gut, leading to solanine absorption resulting in OA. Eliminating solanine from the diet has been reported to bring relief to some arthritis sufferers in preliminary research. Researchers have never put this diet to a strict clinical test; however, the treatment continues to be used by some doctors in people who have OA. Proponents claim exclusion of solanine requires up to six months before potential effects can be seen. Totally eliminating tomatoes and peppers requires complex dietary changes for most people. In addition, even proponents of the diet acknowledge that many arthritis sufferers are not helped by using this approach. Therefore, long-term trial avoidance of solanine-containing foods may only be appropriate for people with severe cases of OA who have not responded to other natural treatments.
Most dietary studies have found that women receiving high amounts of nutrients from fruits and vegetables have less risk of cervical dysplasia. Protective effects may be especially strong from diets high in dark yellow and orange vegetables (carrots, winter squash, etc.) and tomatoes.
Health benefits and
concerns for vegetables
Many health benefits and concerns associated with this food are applicable to other
vegetables. Read about health benefits and concerns
for vegetables for a full description.
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The information presented in Foodnotes is for informational purposes only and was created by a team of U.S. registered dietitians and food experts. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements, making dietary changes, or before making any changes in prescribed medications. Information expires December 2005.