Tomatoes are a popular and nutritious fruit that is commonly considered and used as a vegetable. On average, people consume about 18 pounds (8 kilograms) of tomatoes per year in the United States, according to the U.S. Department of Agriculture (USDA).

Tomatoes contain a wide variety of nutrient and non-nutrient components associated with certain health benefits. These include lycopene, vitamins C, A and K, potassium, and fiber. One medium-sized tomato may provide almost half of a person’s recommended daily amount of vitamin C. Various tomato components are believed to work together to produce  health benefits. These include aiding in the development of healthy teeth, bones, skin and hair; lowering blood pressure and cholesterol levels and possibly reducing the risk of cardiovascular disease and some cancers.

Some tomato components (e.g., lycopene) are more easily absorbed by the body when tomatoes are heated, either during cooking or processing. In addition, carotenoids are fat soluble, so adding small amounts of oil to tomatoes (e.g., in a salad) helps the body absorb the nutrients better. Processed tomato products (e.g., tomato sauce, tomato paste) may contain more health benefits than raw tomatoes.

Tomatoes can be added to the diet in many different ways. Raw tomatoes can be chopped, sliced or grilled and added to omelets, salads, sandwiches and main dishes. Processed tomato products can be added to spaghetti sauce, stews or chili. Tomato juice is a healthy beverage.

Certain nutrient and non-nutrient components of tomatoes may be available in supplement form. However, most experts recommend that people receive nutrients from food sources rather than from supplements. In most cases, the safety and effectiveness of supplements has not been proven.

In addition, the healthful components of tomatoes can be found in a wide variety of fruits and vegetables. The USDA recommends consumption of 3 to 5 servings (about 1 ½ to 2 ½ cups) of vegetables per day, based on a 2,000-calorie-per-day diet. A single serving is equal to one medium-sized tomato, ½ cup cooked tomatoes or 4 ounces of tomato juice.

Most tomatoes sold in supermarkets are picked while unripe, and then artificially ripened. These tomatoes are usually less red, less flavorful and may be less healthy than tomatoes picked when ripe. Consumers can do certain things to trigger or speed the ripening process. They can also avoid permanently interrupting the ripening process by keeping tomatoes out of the refrigerator until fully ripened. Tomatoes are most flavorful and healthy when eaten shortly after they have been allowed to fully ripen. 

The U.S. Food and Drug Administration (FDA) has approved a qualified health claim that associates weekly consumption of tomatoes or tomato sauce with a reduced risk of prostate cancer. The FDA stressed that there is little scientific research to support this claim, however.

Tomatoes are a popular and nutritious plant food. Approximately 18 pounds (8 kilograms) of tomatoes are consumed per person annually in the United States, according to the U.S. Department of Agriculture (USDA). They are the fourth most popular vegetable in America (after potatoes, lettuce and onions), and are one of the most common foods grown in personal gardens. Tomato-based products (e.g., sauces, pastes, ketchup, juice) are consumed more often than raw tomatoes.

According to botanists, tomatoes are technically considered a fruit because they are the berries, with seeds, of a plant that bears fruit. However, according to popular and culinary use, tomatoes are considered a vegetable. They are most often used as a vegetable (e.g., typically served with dinner, not as a dessert).

Tomatoes are more bitter than sweet, although they become sweeter tasting after they have been heated or cooked. The acidity of tomatoes brings out the flavor in other foods, which makes them popular in cooking. It also makes tomatoes easy to preserve in sauces and pastes. Tomatoes may be eaten raw or cooked in all types of meals. Tomato products may be present in ketchup, pizza, spaghetti sauce, soup and vegetable juices. 

The tomato’s fleshy pulp and skin are the edible portion. The seeds are also usually consumed, but they are not digested by the body and pass right through the digestive system. The remainder of the tomato plant is not eaten and parts of it may be toxic.

Tomatoes are available in a wide variety of types, colors, shapes and sizes. The predominant colors are red, yellow and green – but they may come in other colors as well. They range in size from small cherry tomatoes (about 1 to 2 centimeters [cm] in diameter) to medium plum/roma tomatoes (about 4 to 5 cm in diameter, used in sauces and pastes) to large slicing/beefsteak tomatoes (about 10 cm or larger in diameter). Tomatoes are usually round, but may have other shapes (e.g., roma tomatoes are oblong). 

Tomatoes contain an abundance of nutrient and non-nutrient substances believed to be associated with certain health benefits. This includes vitamins C, A, K, potassium, fiber and the phytochemical lycopene.  Lycopene gives tomatoes their red color. The redder the tomato, the more lycopene it contains. Deep red tomatoes contain the most lycopene, a yellow tomato has significantly less lycopene (if any), and a green tomato has no lycopene. Lycopene is fat soluble, which means that when tomatoes are consumed with small amounts of oil, the lycopene is more readily absorbed into the body, increasing the healthful effects of tomatoes.

Processed tomato products contain more nutrients than fresh tomatoes due to higher concentration levels in a small amount of product. In addition, certain substances in tomatoes (e.g., lycopene), when heated during processing or cooking, are more easily absorbed into the body.

Tomatoes have few drawbacks. They are acidic, so they may cause an upset stomach in some people. People who are prone to heartburn may experience gastrointestinal discomfort when eating tomatoes or tomato-based products.  People who consume large amounts of lycopene-rich foods or supplements may develop a deep orange skin discoloration known as lycopenodermia. There is no reported toxicity associated with lycopene in tomatoes.

Certain medications or conditions may inhibit the absorption of fat-soluble substances (such as the carotenoids in tomatoes) in the body. Drugs or conditions that cause malabsorption may do this, as well as mineral oil and certain drugs designed to lower cholesterol levels or treat obesity.

Tomatoes contain a wide variety of nutrients and non-nutrient substances that may benefit a person’s health. It is believed that these components work together to create the health benefits and that taken individually, the components are probably not responsible for the health-benefitting properties of tomatoes.

Tomato components and their associated health benefits include:

• Lycopene. A phytochemical that is classified as a type of carotenoid. It is responsible for the red color of tomatoes and other fruits and vegetables. The redder a tomato is, the more lycopene it contains. Lycopene is a powerful antioxidant and may help reduce the risk of some cancers and cardiovascular disease. Unlike other carotenoids, lycopene is not converted into vitamin A by the body.
  
  Lycopene is a fat soluble substance that is found in the blood and tissues of the testes, adrenal glands, liver, prostate, breast, colon and lungs. The precise activity of lycopene in the human body requires more study. Current scientific evidence about the association between lycopene and certain health benefits is mixed and remains controversial.
  
  Tomato products contain higher concentrations of lycopene than any other plant source, although lycopene is available in other plant foods, such as watermelon, papaya, pink grapefruit and guava. Tomatoes and tomato products are the primary sources of lycopene for most people in the United States.
  
  
• Vitamin C. An essential vitamin that also acts as an antioxidant. It may help reduce blood pressure and cholesterol levels. Vitamin C helps form connective tissue, keeps capillaries healthy to help prevent easy bruising, and keeps the gums healthy. It also helps the body access iron from non heme, or plant, sources.
  
  
• Vitamin A. An essential vitamin important in maintaining normal cellular growth. It aids in the development of healthy skin, hair and mucous membranes. It also aids proper vision, development of bones and teeth and reproduction. Tomatoes contain beta-carotene, a phytochemical that the body converts into vitamin A after it is consumed.
  
  
• Vitamin K. A vitamin important to maintain blood clotting, thus helping to prevent hemorrhaging (excessive, uncontrollable bleeding). Vitamin K is also important to maintain bone health through the act of mineralization. Vitamin K may be obtained from foods such as tomatoes, but may also be produced by bacteria in the intestines.
  
  
• Potassium. An essential mineral that helps regulate blood pressure and aids muscle contractions. It may reduce the risk of kidney stones and bone loss.
  
  
• Dietary fiber. The undigestible part of a plant. Fiber can aid digestion by preventing constipation).

In lesser quantities, tomatoes also include many more vitamins, minerals and other healthful substances. These include: various B vitamins (including folate), vitamin E, calcium, magnesium, iron, phosphorus, tryptophan and protein.

One medium tomato (148 grams) contains the following proportion of recommended daily levels of certain nutrients, based on a 2,000-calorie/day diet:

Most experts recommend receiving essential nutrients from food sources rather than relying on supplements. A variety of healthy foods, such as adequate daily levels of fruits, vegetables, protein, whole grains and dairy products can provide all the nutrients necessary for most healthy people. In addition, foods contain a wide variety of vitamins, minerals and non-nutrient substances (e.g., phytochemicals) in a single serving. Supplements, including multivitamins, may contain a more limited number of nutrients. Also, foods are less likely to contain toxic levels of any one substance that may harm the body.

Tomatoes can be easily incorporated into a healthy diet. They can be eaten with almost every meal. Fresh tomatoes can be added to omelets, salads, sandwiches and many different dishes such as tacos and casseroles. They can also be sliced and grilled with cheese as a healthy snack. Processed tomato products, such as tomato sauce, paste or puree, can be used in soups, stews, chili, meat loaf, pizza and pasta dishes.

The U.S. Department of Agriculture (USDA) recommends consuming 3 to 5 servings (about 1 ½ to 2 ½ cups) of vegetables per day, based on a 2,000-calorie/day diet. When determining how many tomatoes or tomato products constitute a serving, the following guide may help:

• 4 ounces tomato juice = 1 serving
• ½ cup cooked tomato = 1 serving
• 1 medium-sized tomato = 1 serving
• large salad = 2 to 4 servings

The healthful components of tomatoes may also be found in other food sources. For example, lycopene, the primary phytochemical found in tomatoes, can also be found (although in lesser quantities) in red/pink grapefruit, watermelon, papaya and guava. Vitamin C and beta-carotene are available in many different fruits and vegetables.

For all types of dietary supplements, it is the responsibility of the manufacturer or distributor to determine that their products are safe and product claims are substantiated by adequate evidence to show they are not false or misleading. In most cases, no evidence is required to be provided to a regulating body and most supplements on the market have not been reviewed or approved by the U.S. Food and Drug Administration (FDA).

In addition, supplements may adversely interact with medications (both prescription and over-the-counter), other supplements, certain foods and certain medical conditions. Too much of certain dietary ingredients in supplements can lead to toxic buildup in the body. Side effects can range from unpleasant to deadly. Consumers should consult their physician or registered dietitian about whether a particular supplement may be appropriate for them.

The best tomatoes are picked when ripe and consumed shortly thereafter. Most tomatoes sold in supermarkets are harvested while unripe (and green) and ripened with the use of ethylene (a gas naturally produced by many fruits that triggers the ripening process). Tomatoes ripened in this manner usually appear less red (they may be pink or orange), are less flavorful and may contain less of certain substances (e.g., the phytochemical lycopene) than tomatoes that are picked after they have already ripened.

If purchased or picked unripe, tomatoes may be ripened by placing them in a paper bag along with a banana or apple. These fruits emit ethylene that can trigger ripening. However, the ripening process may be permanently interrupted when tomatoes are exposed to cold temperatures.

The enzyme in a tomato that causes it to ripen stops working when exposed to temperatures of 54 degrees Fahrenheit (12 degrees Celsius) or lower. Once exposed to this level of cold, tomatoes will not continue to ripen. Thus, many store-bought tomatoes that are taken home and stored in the refrigerator before fully ripening may not be as tasty, red or nutritious as those allowed to ripen at warmer temperatures.

When shopping, consumers are advised to look for the following signs of a healthy tomato:

• Plumpness
• Smooth skin with good color
• Mostly firm to the touch
• Sweet aroma

In November 2005, the U.S. Food and Drug Administration (FDA) approved a qualified health claim regarding tomatoes and the risk of prostate cancer. It recommends that weekly consumption of ½ cup to 1 cup of tomatoes or tomato sauce may help reduce the risk of prostate cancer. However, the FDA stressed that there is little scientific research to support this claim.

Preparing questions in advance can help patients have more meaningful discussions with health professionals regarding their conditions. Patients may wish to ask their doctor or registered dietitian the following questions related to tomatoes:

1. How do tomatoes benefit me in my present state of health?
   
   
2. Are certain types of tomatoes (e.g., cherry tomatoes vs. beefsteak tomatoes, red vs. yellow or green tomatoes) better for me than other types?
   
   
3. What vitamins, minerals or other substances do I get from tomatoes?
   
   
4. What does lycopene do in my body?
   
   
5. Should I purchase organic tomatoes? Why or why not?
   
   
6. Are foods that contain processed tomato products (e.g., spaghetti with a tomato-based sauce) better for me than eating fresh tomatoes? Why?
   
   
7. Would you recommend I use a dietary supplement, such as one that contains lycopene?
   
   
8. How often should I include tomatoes in my diet?
   
   
9. How do you recommend I add more tomatoes into my diet?
   
   
10. Are there specific foods I should consume along with tomatoes for better absorption in my body?
    
    
11. Will I experience any adverse effects of eating too many tomatoes or tomato-based products?