Tomatoes are healthy, versatile and nutrient-rich — you'll find them in foods ranging from salad to pizza to soup. It's hard to eat too many tomatoes, but it is possible. Excessive tomato consumption is related to gastrointestinal, kidney, urinary and other health issues.
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Tomato Nutrition Facts
Tomatoes, which are technically a fruit, are usually considered a vegetable in the kitchen. You're likely to find tomatoes in a range of savory dishes, including pasta sauces, bruschetta, soups and curries. However, this plant is extremely versatile. You can snack on plain cherry tomatoes or include them in salads. You can also consume sweeter products like tomato juice and even use tomatoes to make cocktails.
The Dietary Guidelines for Americans recommends consuming around 2 cups of fruits and 2.5 cups of vegetables each day. These guidelines classify the tomato as a vegetable — and say it's one of the most popular types. Tomatoes make up a total of 18 percent of all vegetable consumption.
According to the USDA, a cup of raw tomatoes is equivalent to about 180 grams (around 6.3 ounces). This amount of tomatoes contains 32 calories, 0.4 grams of fat, 7 grams of carbohydrates (2.2. grams from dietary fiber) and 1.6 grams of protein.
Tomatoes are also rich in a variety of essential nutrients. In every cup of tomatoes, you will find:
- 9 percent of the daily value (DV) for manganese
- 9 percent of the DV for potassium
- 5 percent of the DV for magnesium
- 12 percent of the DV for copper
- 8 percent of the DV for vitamin A
- 27 percent of the DV for vitamin C
- 6 percent of the DV for vitamin B1 (thiamin)
- 7 percent of the DV for vitamin B3 (niacin)
- 8 percent of the DV for vitamin B6
- 7 percent of the DV for vitamin B9 (folic acid)
- 6 percent of the DV for vitamin E
- 12 percent of the DV for vitamin K
Tomatoes also contain small amounts of other vitamins and minerals, including calcium, choline, B-complex vitamins, iron, phosphorus and zinc. Each cup of tomatoes also contains nutrients like lutein and zeaxanthin. According to an August 2018 study in the Journal of Food Science and Technology, tomatoes are rich in phenolic compounds, carotenoids like lycopene and other beneficial bioactive nutrients.
Read more: The 14 Best Foods for Your Heart
Tomato Advantages and Disadvantages
Tomatoes have a variety of well-known health benefits, but are perhaps best known for their cardioprotective effects. According to a February 2017 study in the Atherosclerosis journal, consumption of tomatoes can positively affect blood lipid levels and blood pressure thanks to its lycopene content.
A January 2015 article in the journal Critical Reviews in Food Science and Nutrition reported that tomato consumption is only only helpful in minimizing cardiovascular problems, but can reduce the risk of other health issues like high cholesterol, obesity and cancer. A small January 2017 study in the Asia Pacific Journal of Clinical Nutrition even found that regular consumption of tomato juice could help improve sperm motility in infertile men.
However, like any food, tomatoes have advantages and disadvantages. According to A January 2019 study in the Journal of Nutrition, tomatoes are generally safe to eat. But both regular and excessive consumption of tomatoes have the potential to affect your health. For example, tomatoes are among the leading causes of migraines.
When you eat too many tomatoes, you may experience symptoms of acid reflux. That can affect people who are otherwise perfectly healthy. It is a well-known trigger food for people with existing gastroesophageal reflux disease (GERD). This is likely from the large amount of malic acid and citric acid found in tomatoes.
Too many tomatoes can also trigger other gastrointestinal issues, like irritable bowel syndrome. Consumption of tomatoes has been known to produce side effects like bloating and diarrhea in certain people, which are common symptoms of IBS.
It's also possible to consume too much lycopene, a carotenoid that tomatoes are rich in. If you eat too many tomatoes, it could lead to large amounts of lycopene building up in your bloodstream. Although lycopene isn't bad for you, this can eventually cause a skin discoloration condition called lycopenodermia. Although your skin may turn orange, the condition is reversible and relatively harmless.
It's also possible to develop an intolerance or allergy to tomatoes. The tomato plant has a variety of compounds your body may react to, including b-fructofuranosidase, profilin, superoxide dismutase, pectinesterase, polygalacturonase and the lipid transfer proteins cyclophilin, lyc e-2 and lyc e-3. This essentially means that there's a lot of crossover between the allergenic compounds in tomatoes and other foods or plants you might be allergic to.
Read more: The 10 Worst Foods for Acid Reflux
Other Disadvantages of Eating Tomatoes
The Journal of Nutrition study also reported some other disadvantages of eating tomatoes. For instance, acidic foods, fruits, vegetables and caffeinated beverages like coffee and tea have the potential to irritate the bladder. These foods can increase the risk of urinary problems like incontinence. This study reported that products like spicy foods, vitamin C, citrus fruits and tomatoes were all particularly likely to exacerbate bladder problems.
Like other nightshade plants, tomatoes contain toxic glycoalkaloids. Green tomatoes are particularly well known for containing glycoalkaloid compounds like solanine, a-tomatine and dehydrotomatin. Unfortunately, glycoalkaloids can cause gastrointestinal tract disorders and pain when consumed in large amounts. They are also suspected to exacerbate inflammation. This means excessive tomato consumption can aggravate chronic pain and painful inflammatory conditions like arthritis.
Finally, tomatoes can also affect people with existing kidney conditions. Although the nutrients in tomatoes can help protect people from kidney issues, tomato consumption may not be suitable for people who already have kidney problems. Tomatoes contain oxalate and calcium, which are both associated with kidney stone formation. They're also a good source of potassium.
Although potassium is an essential nutrient, those with kidney problems need to reduce their intake of this nutrient. That being said, there is only 9 percent of the DV for potassium in every cup of tomatoes, so people with kidney problems are mainly likely to encounter this issue after consuming too many tomatoes.
- Linus Pauling Institute: Micronutrient Information Center: "Carotenoids"
- Critical Reviews in Food Science and Nutrition: "Tomato (Solanum lycopersicum) Carotenoids and Lycopenes Chemistry; Metabolism, Absorption, Nutrition, and Allied Health Claims—A Comprehensive Review"
- Health.gov: "Dietary Guidelines for Americans, 2015-2020"
- MyFoodData: "Nutrition Facts for Tomatoes"
- Asia Pacific Journal of Clinical Nutrition: "The Effects of Tomato Juice on Male Infertility"
- Journal of Food Science and Technology: "Bioactivities of Phytochemicals Present in Tomato"
- Atherosclerosis: "Tomato and Lycopene Supplementation and Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis"
- Nutrition: "Beneficial Effects and Potential Risks of Tomato Consumption for Human Health: An Overview"