Whether you refer to a tomato as a fruit or a vegetable, there is no doubt that a tomato is a nutrient-dense, super-food that most people should be eating more of.
The tomato has been referred to as a "functional food," a food that goes beyond providing just basic nutrition, additionally preventing chronic disease and delivering other health benefits, due to beneficial phytochemicals such as lycopene.
Despite the popularity of the tomato, only 200 years ago it was thought to be poisonous in the U.S., likely because the plant belongs to the nightshade family, of which some species are truly poisonous.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods.
Nutritional breakdown of tomatoes
One medium tomato (approximately 123 grams) provides 22 calories, 0 grams of fat, 5 grams of carbohydrate (including 1 gram of fiber and 3 grams of sugar) and 1 gram of protein. Tomatoes are a rich source of vitamins A and C and folic acid. Tomatoes contain a wide array of beneficial nutrients and antioxidants, including alpha-lipoic acid, lycopene, choline, folic acid, beta-carotene and lutein.
Tomatoes are packed full of beneficial nutrients and antioxidants and are a rich source of vitamins A and C and folic acid.
Alpha-lipoic acid helps the body to convert glucose into energy. Some evidence suggests that alpha-lipoic acid can aid in blood glucose control, improve vasodilation and protect against retinopathy in diabetic patients and may even help preserve brain and nerve tissue.1
Lycopene is the antioxidant that gives tomatoes their rich red color. Tomatoes account for 80 percent of lycopene consumption.
Choline is an important nutrient found in tomatoes that helps with sleep, muscle movement, learning and memory. Choline also helps to maintain the structure of cellular membranes, aids in the transmission of nerve impulses, assists in the absorption of fat and reduces chronic inflammation.2
Possible health benefits of consuming tomatoes
The benefits of consuming fruits and vegetables of all kinds, including tomatoes, are infinite. As plant food consumption goes up, the risk of heart disease, diabetes, and cancer goes down. High fruit and vegetable intake is also associated with healthy skin and hair, increased energy and lower weight. Increasing consumption of fruits and vegetables significantly decreases the risk of obesity and overall mortality.
Cancer: As an excellent source of the strong antioxidant vitamin C and other antioxidants, tomatoes can help combat the formation of free radicals known to cause cancer.
Prostate Cancer: Lycopene has been linked with prostate cancer prevention in several studies.7 According to John Erdman, Ph.D., Professor Emeritus of the department of food science and human nutrition at the University of Illinois, "There's very good, strong, epidemiological support for increased consumption of tomato products and lower incidence of prostate cancer."7
Colorectal Cancer: Beta-carotene consumption has been shown to have an inverse association with the development of colon cancer in the Japanese population. High fiber intakes from fruits and vegetables are associated with a lowered risk of colorectal cancer.
According to the American Cancer Society, some studies have shown that people who have diets rich in tomatoes may have a lower risk of certain types of cancer, especially cancers of the prostate, lung, and stomach. Further human-based research is needed to find out what role lycopene might play in the prevention or treatment of cancer.
Blood pressure: Maintaining a low sodium intake is essential to lowering blood pressure, however increasing potassium intake may be just as important because of its vasodilation effects. According to the National Health and Nutrition Examination Survey, fewer than 2 percent of U.S. adults meet the daily 4700 mg recommendation.3
Also of note, a high potassium intake is associated with a 20 percent decreased risk of dying from all causes.3
Heart health: The fiber, potassium, vitamin C and choline content in tomatoes all support heart health. An increase in potassium intake along with a decrease in sodium intake is the most important dietary change that a person can make to reduce their risk of cardiovascular disease, according to Mark Houston, M.D., M.S., an associate clinical professor of medicine at Vanderbilt Medical School and director of the Hypertension Institute at St. Thomas Hospital in Tennessee.3
In one study, those who consumed 4069 mg of potassium per day had a 49 percent lower risk of death from ischemic heart disease compared with those who consumed less potassium (about 1000 mg per day).3
High potassium intakes are also associated with a reduced risk of stroke, protection against loss of muscle mass, preservation of bone mineral density and reduction in the formation of kidney stones.3
Diabetes: Studies have shown that type 1 diabetics who consume high-fiber diets have lower blood glucose levels and type 2 diabetics may have improved blood sugar, lipids and insulin levels. One cup of cherry tomatoes provides about 2 grams of fiber.
The Dietary Guidelines for Americans recommends 21-25 g/day for women and 30-38 g/day for men.
Skin: Collagen, the skins support system, is reliant on vitamin C as an essential nutrient that works in our bodies as an antioxidant to help prevent damage caused by the sun, pollution and smoke, smooth wrinkles and improve overall skin texture.5
Constipation: Eating foods that are high in water content and fiber like tomatoes can help to keep you hydrated and your bowel movements regular. Fiber is essential for minimizing constipation and adding bulk to the stool.
Pregnancy: Adequate folic acid intake is essential for pregnant women to protect against neural tube defects in infants.
Depression: The folic acid in tomatoes may also help with depression by preventing an excess of homocysteine from forming in the body, which can prevent blood and other nutrients from reaching the brain. Excess homocysteine interferes with the production of the feel-good hormones serotonin, dopamine, and norepinephrine, which regulate not only mood, but sleep and appetite as well.4
Recent developments on the health benefits of tomatoes from MNT news
Risk of breast cancer for postmenopausal women may reduce with a tomato-rich diet, after a study showed the diet increased levels of adiponectin - a fat and blood sugar regulator.
Men who consume plenty of soy and tomato combinations probably have a much lower risk of developing prostate cancer compared to those who don't.
Results of a study published in the journal PLOS One, revealed that CVD patients who received lycopene supplementation showed improved blood vessel response to acetylcholine, compared with healthy volunteers, which indicated normalized endothelial function.
How to incorporate more tomatoes into your diet
Make sure to store fresh tomatoes at room temperature. Avoid refrigeration, as this causes tomatoes to lose their flavor.
Tomatoes can be easily incorporated into your daily diet, from using them in sauces and soups to creating a quick bruschetta appetizer.
- Dip grape or cherry tomatoes in hummus or plain yogurt dip and have as a side or a snack.
- Always add sliced tomato to your sandwiches and wraps.
- Add diced canned tomatoes (low sodium) to homemade or jarred marinara sauces when making pasta.
- Used canned diced or stewed tomatoes in soups.
- Have a piece of toast with avocado and tomato slices.
- Make your own quick salsa with diced tomatoes, onion, jalapeno, cilantro and freshly squeezed lime.
- Dice fresh tomatoes and add them to rice and beans, quesadillas or tacos. Add them to your omelets or scrambles for breakfast.
- Drizzle freshly sliced tomatoes and sliced mozzarella with balsamic vinegar and top with chopped basil.
- Make a quick bruschetta for an appetizer.
Risks and Precautions
The Environmental Working Group (EWG) produces a list each year of fruits and vegetables with the highest levels of pesticide residue, known as the Dirty Dozen. Cherry tomatoes are high on the list of produce that the EWG suggests that you buy in the organic version to ensure a lower risk of pesticide exposure. If you can not afford organic, do not fret; the nutritional benefit of eating conventionally grown (non-organic) produce far outweighs the risk of not eating produce at all.
Beta-blockers, a type of medication most commonly prescribed for heart disease, can cause potassium levels to increase in the blood. High potassium foods such as tomatoes should be consumed in moderation when taking beta-blockers.
Consuming too much potassium can be harmful for those whose kidneys are not fully functional. If your kidneys are unable to remove excess potassium from the blood, it could be fatal.
Those with gastro-esophageal reflux disease (GERD) may experience an increase in symptoms such as heartburn and regurgitation when consuming highly acidic foods such as tomatoes, however individual reactions vary.
It is the total diet or overall eating pattern that is most important in disease prevention and achieving good health. It is best to eat a diet with variety than to concentrate on individual foods as the key to good health.
Written by: Megan Ware, RDN, LD