Tomatoes are technically a fruit because they fit the botanical definition of one: they are the fleshy parts of a plant that surround its seeds. However, for nutritional and culinary purposes, tomatoes are considered a vegetable due to their flavor, use in meals, and nutrient content.
For ripe red tomatoes, 100 grams have the following, according to the USDA:
- calories: 18 calories
- Fat: <1 gram
- Cholesterol: 0 milligrams
- Sodium: 5 milligrams
- carbohydrates:3.89 grams
- Fiber: 1.20 grams
- Protein: <1 gram
Tomatoes are low in calories and provide important nutrients such as vitamin C and potassium. They are also rich in antioxidants: one called lycopene, responsible for the characteristic color of tomatoes, is linked to several benefits, such as reducing the risk of heart disease and certain types of cancer.
Research shows that tomatoes in many forms (fresh, cooked, and juiced) help protect against chronic diseases and support a physically active lifestyle.
May help protect brain health
In the United States, 10% of adults age 65 and older have Alzheimer’s disease. The disease, which affects memory, thinking and behavior, is a form of dementia that has no cure and worsens over time.
While more research is needed on the connection between tomatoes and AD, studies have suggested that antioxidants in tomatoes, such as lycopene, may protect against neurodegenerative diseases such as AD. One study showed that, over four years, there was a slower decline in cognitive function among participants aged 70 and older who consumed a high level of lycopene.
More research is needed in humans, specifically in adults ages 60 to 65, to better understand the true connection between the potential protective benefits of tomatoes and AD and other neurodegenerative diseases such as Parkinson’s disease.
It can help combat metabolic syndrome.
Metabolic syndrome is a group of conditions that increase the risk of heart disease, diabetes, stroke, and other serious health problems. It implies having three or more of the following conditions:
- a big waist
- Hypertension
- high blood sugar
- High blood triglycerides or fats
- Low “good” HDL cholesterol
About one in three American adults has metabolic syndrome. Researchers say that lycopene level (that is, the amount of lycopene in the blood) or lycopene consumption may be associated with favorable changes in components of metabolic syndrome. And tomatoes are a major contributor of lycopene.
In one small study, 15 participants drank tomato juice once a day, four times a week for two months, with no specified amount. Despite the lack of a standardized serving of juice, the group experienced significant decreases in “bad” LDL cholesterol, increases in “good” HDL cholesterol, and improvements in fasting insulin levels.
Helps protect heart health.
A diet rich in tomatoes has been linked to a reduced risk of heart disease, the leading cause of death among adults in the US. A review of 25 previously published studies reported that a high intake of lycopene, as well as high levels of the antioxidant in the blood, reduced the risk of heart disease by 14%.
Another study of healthy people looked at the effect of a single dose of raw tomatoes, tomato sauce, or tomato sauce plus olive oil on measures related to heart disease risk. All three doses lowered blood cholesterol and triglycerides (a type of fat in the blood) and increased HDL cholesterol and anti-inflammatory levels. Tomato sauce plus olive oil had the greatest effect, probably because olive oil increased lycopene absorption.
It can help prevent constipation.
Lack of fluid and fiber can cause constipation. Tomatoes provide both nutrients: A whole tomato contains more than four ounces of liquid and one and a half grams of fiber.
The water content and dietary fibers found in tomatoes are known to support hydration and healthy bowel movements. Tomatoes are an important source of soluble and insoluble dietary fibers. Soluble fiber retains water to create a gel-like texture during digestion, while insoluble fiber adds bulk to stool. Both changes form waste that is easier to remove. Specifically, the cellulose, hemicelluloses, and pectin fibers in tomatoes are resistant to digestion in the large intestine and help form healthy stools.
May help prevent type 2 diabetes
Among American adults, 14.7% have type 2 diabetes and 38% have prediabetes, when blood sugar levels are too high but not yet high enough to be diagnosed as type 2 diabetes. Some research shows that the antioxidant properties of lycopene contribute to the prevention of type 2 diabetes. This is due to its ability to protect cells from damage, reduce inflammation, and stimulate the body’s defense mechanisms. The fiber in tomatoes may also help protect against diabetes.
May reduce cancer risk
Lycopene and beta-carotene, two antioxidants found in tomatoes, have been shown to have anti-cancer properties. They do this in part by protecting against the type of damage to the cells’ DNA that can lead to the development of cancer and causing the death of cancer cells.
Several studies have found that men with a higher consumption of tomatoes (particularly cooked tomatoes) have a lower risk of prostate cancer. And in general, eating non-starchy vegetables like tomatoes has been linked to a lower risk of estrogen receptor-negative breast tumors, as well as cancer of the colon, rectum, lung, stomach, and upper aerodigestive tract (such as the mouth, throat and sinuses).
May support recovery from exercise.
Exercise can damage the body’s proteins, and research shows that the antioxidants in tomatoes can help offset the effects. A study in athletes found that drinking 3.5 ounces of tomato juice for two months after exercise improved athletes’ recovery. In another study, 15 healthy non-athletes exercised for 20 minutes on a bicycle after drinking 5 ounces of tomato juice for five weeks, followed by five weeks without tomato juice and another five weeks with juice. Blood samples showed that when tomato juice was consumed, there were significantly lower blood markers associated with exercise damage.
May help immune function
The vitamin C and beta-carotene in tomato juice can help support the immune system. One study found that tomato juice significantly increased levels of immune cells, including a type called natural killer cells that are known to fend off viruses.
May support male fertility
One study looked at the effects of 190 grams (nearly 7 ounces) of tomato juice daily versus an antioxidant capsule or a placebo among male infertility patients for 12 weeks. Compared to the control (placebo) group, tomato juice significantly increased blood lycopene levels in men and sperm movement, an indicator of fertility. The antioxidant capsule, however, did not show significant improvements.
A whole tomato provides the following:
- Calories: 22.5
- Carbohydrates: 4.86g
- Fat: 0.25g
- Protein: 1.1g
- Vitamin C: 17.1 mg, 19% of the daily value
- Potassium: 296 mg, 6% of the daily value
- Vitamin K: 9.88 mcg, 8% of the daily value
- Folate: 18.8 mcg, 4.7% of the daily value
The vitamin C in tomatoes acts as an antioxidant and is important for skin, bones and connective tissue. It also promotes healing and helps the body absorb iron.
Potassium is a mineral necessary to form proteins in the body, including muscles; break down and utilize carbohydrates; and regulate heart rhyme and pH balance.
Vitamin K is necessary for blood to clot and also helps maintain strong bones in older adults.
Folate helps make DNA, the building block of the human body. It also helps form red blood cells to prevent anemia and works with vitamins B12 and C to help the body break down, use and create new proteins and tissues.
Consuming tomatoes in other forms, such as juice, sauce or paste, changes the nutritional information compared to whole fresh tomatoes. Check nutrition labels to evaluate calories and nutrient levels. And read ingredient lists to identify potential additives, such as sodium or sugar.
As with any fresh produce, raw tomatoes can carry germs such as listeria either Salmonella, which causes foodborne illnesses. This is a greater concern for those who: are pregnant, are over 65, are under the age of five, have health problems, or take medications that reduce the body’s ability to fight germs and diseases. This includes those living with diabetes, liver or kidney disease, HIV or cancer. To reduce the risk, you can cook your produce or, if using raw tomatoes, wash them.
Additionally, tomatoes can worsen existing conditions such as gastroesophageal reflux disease (GERD) or migraine. Talk to your healthcare provider to determine if you need to avoid tomatoes for any reason.
Many of the benefits of consuming tomatoes are linked to their lycopene content. Research shows that field-grown tomatoes contain higher levels of lycopene than those grown in greenhouses. Additionally, cooking tomatoes increases their lycopene content. And eating them with fats, such as avocado or extra virgin olive oil, increases the absorption of lycopene from the digestive tract into the bloodstream.
Having said all that, to reap the full range of positive benefits, it is recommended to consume tomatoes regularly in various forms, including raw and cooked. Add raw tomatoes to anything from omelettes to avocado toast and salads. Enjoy it as fresh pico de gallo. Top fresh tomatoes with hummus, olive tapenade, or vegetable vinaigrette. Grill or bake raw tomatoes, or enjoy cooked tomatoes in paste, salsa, and salsa forms, incorporated into a variety of dishes such as soup, pasta, chili, and tacos. Drink tomato juice as is or use it as a base for gazpacho.
Tomatoes offer several potential benefits backed by research, including protecting brain, heart, and gut health. The vegetable, which is also considered a fruit, is a solid source of nutrients such as vitamin C, potassium, and antioxidants, namely lycopene.
There may be some potential downsides to consuming them, especially depending on your health status, but most people can eat raw and cooked tomatoes as part of a balanced diet. For guidance on whether tomatoes and the nutrients like lycopene they contain can help with a specific condition, talk to a healthcare provider.