6 Possible Side Effects of Eating Too Many Tomatoes

Tomatoes are nutritious and versatile ⁠— you can find them in foods ranging from salad to pizza to soup.

And no shocker here: Tomatoes are generally safe to eat, according to a June 2019 review in ‌Nutrition‌. It's hard to eat too many tomatoes, but it if you do, it might lead to gastrointestinal, kidney, urinary and other side effects.

Allergies, sensitivities and intolerances to tomatoes are all possible. Tomatoes are part of the nightshade family, so anyone with a sensitivity to nightshades will have a tomato sensitivity as well.

Tomatoes are among the most prevalent allergenic produce, according to an April 2022 review in ‌Antioxidants‌. People with grass pollen and latex allergies may also have a tomato allergy.

"Most people won't experience hives from eating too many tomatoes, but it is still a possibility," says registered dietitian Jenna Volpe, RDN, LD. "This is because tomatoes are naturally high in a chemical called histamine."

If you're susceptible to headaches and migraines, tomatoes may worsen your symptoms. Certain foods can trigger headaches, and tomato-based products like pizza are among them, according to the Cleveland Clinic.

Some experts recommend people with migraines avoid eating tomatoes, according to February 2012 research in the ‌Iranian Journal of Nursing and Midwifery Research‌.

To figure out if tomatoes are triggering your headaches or migraines, track your food intake. Food-related headaches usually arrive 20 minutes to 2 hours after eating specific foods. Whole tomatoes may be more well-tolerated than processed tomato-based foods.

Tomatoes are associated with an increased risk of heartburn and gastroesophageal reflux disease (GERD).

Anyone can experience acid reflux after eating acidic foods like tomatoes, including folks without any pre-existing health conditions. Tomatoes, specifically, have high amount of malic acid and citric acid.

"While there could be many underlying reasons why a person is experiencing heartburn and acid reflux, acidic foods are well-known to be a common trigger for people who are prone to heartburn and GERD," Volpe says.

Eating too many tomatoes can also trigger other gastrointestinal issues, like irritable bowel syndrome (IBS). Eating a lot of tomatoes can produce side effects like bloating and diarrhea (which are also common symptoms of IBS) in certain people. They can also cause stomach aches, gastritis and sensitivity.

"Tomatoes contain ascorbic acid and other acidic compounds, which, in excess, can erode the lining of the stomach," Volpe explains. "This may lead to an acute onset stomach ache or mild gastritis in someone with a sensitive stomach."

Like other nightshade plants, tomatoes contain toxic glycoalkaloids. Green tomatoes are particularly known for containing glycoalkaloid compounds like solanine, a-tomatine and dehydrotomatin. Unfortunately, glycoalkaloids can cause gastrointestinal tract disorders and pain when eaten in large amounts.

Tomatoes are rich in carotenoids like lycopene, a powerful antioxidant. It won't cause any harm but can have some unwanted effects when eaten in large amounts.

When eaten in excess, lycopene can build up in your bloodstream. This can eventually cause a skin discoloration condition called lycopenodermia, causing your skin to turn orange. Although you may not like the way this skin condition looks, it is reversible and relatively harmless.

There are no upper levels of lycopene intake and it's generally safe to eat, according to August 2005 research in ‌The Journal of Nutrition‌.

Tomatoes have the potential to irritate the bladder, according to the Cleveland Clinic. This includes symptoms like strong urges to pee, frequent trips to the bathroom and pain in the lower abdomen.

With age, bladder control (aka incontinence) can become a problem. Tomato-based foods (among other diuretic foods) are known to worsen bladder problems, according to the National Institute on Aging.

Getting enough fluids is vital for preventing kidney stones, but tomato juice is off-limits due to the high sodium content, according to December 2014 research in the ‌Korean Journal of Urology‌.

Those with kidney disease might want to limit their intake of tomatoes because they're high in potassium, per the National Institute of Diabetes and Digestive and Kidney Diseases.

Having a serving of tomatoes likely won't cause side effects, but eating too many tomatoes or having a sensitivity to them can increase the likelihood.

If you experience side effects after eating tomatoes, Volpe recommends the following remedies to soothe your symptoms:

• Take a calcium supplement to alleviate stomach aches and gastritis.
• Take an antihistamine for hives and allergic reactions.
• Drink bone broth to soothe reflux after eating too many acidic tomatoes.

Tomatoes are safe to eat, according to the June 2019 review in ‌Nutrition‌. They're full of beneficial vitamins and minerals, making them a nutritious addition to most meal plans.

Still, there may be groups who would benefit from reducing their tomato intake, including:

• People who experience frequent migraines
• People with GERD
• People with kidney disease

If you're concerned that tomatoes may worsen your health condition, speak with your doctor or dietitian. Otherwise, tomatoes are a perfectly nutritious fruit to enjoy.