Watermelon

Studies in people

• No harm found

  Body fat and muscle²

  In people, citrulline supplements, including watermelon juice, had no overall effect on body weight or fat.

• Benefit

  Blood pressure in older adults³

  In middle-aged and elderly people, l-citrulline and watermelon lowered blood pressure.

• Open question

  Blood pressure and cholesterol⁴

  In people, eating watermelon lowered blood pressure and cholesterol, but raised fasting blood sugar.

• Benefit

  Blood pressure⁵

  Watermelon contains L-citrulline, which may lower resting blood pressure in people with prehypertension or hypertension.

• Benefit

  Blood pressure and arteries⁶

  Watermelon products with enough L-citrulline may lower blood pressure and artery stiffness, but studies disagree.

• Benefit

  Blood pressure and heart health⁷

  In adults at risk for heart disease, watermelon's L-citrulline may improve blood vessel function, but more evidence is needed.

• Benefit

  Weight management⁸

  Eating watermelon has shown benefits for managing weight in people, though scientists say more studies are needed.

• No harm found

  Blood vessel health⁹

  Drinking watermelon juice daily for a month did not change blood vessel measures in healthy postmenopausal women.

• Benefit

  Weight and blood sugar in children¹¹

  In children with overweight, eating blended watermelon daily lowered body fat and a blood sugar marker.

• Benefit

  Leg artery stiffness¹²

  In women, drinking wild watermelon juice eased leg artery stiffness and boosted blood flow.

• Concern

  Migraine headaches¹³

  In people with migraine, watermelon was the plant food most often reported to trigger a headache.

• Open question

  Blood pressure and exercise¹⁴

  Watermelon juice raised resting blood pressure in healthy men and did not improve how long they could exercise.

• Concern

  Headache in migraine sufferers¹⁸

  In people with migraine, eating watermelon triggered headaches in about a quarter of them.

• Benefit

  Heart rhythm after a sugary drink¹⁹

  In healthy young adults, two weeks of daily watermelon juice lessened the drop in heart rhythm measures after a sugary drink.

• Benefit

  Diet quality and nutrients²⁰

  People who ate watermelon took in more fiber, potassium, and vitamins and had better overall diets.

• Benefit

  Blood pressure after exercise²¹

  In women, watermelon juice stopped blood pressure rising after exercise, but not in men.

Study type not stated

• Benefit

  Health effects in people²⁵

  Watermelon lycopene may help with cancer, heart disease and diabetes, but studies in people are still needed.

Found in some samples or products

These come from where it was grown, how it was processed or cooked, or what it was made into. They are not about the ingredient itself, so the signal does not count them.

• Pesticide in melons¹⁰

  In Oregon, aldicarb was found in watermelons that made 61 people sick.

• Food poisoning outbreak²³

  In a New Zealand outbreak, people who got sick were seven times more likely to have eaten watermelon.

• Fungicide breakdown on fruit²⁶

  A fungicide called mefentrifluconazole was found on watermelon in China, and one form of it broke down slower than the other.

Allergies and intolerances

These are about people with an allergy, an intolerance or coeliac disease. The signal is about the ingredient itself, and these are about the person eating it, so the signal does not count them.

• Profilin reactions¹⁶

  Watermelon profilin is a major allergen that sets off reactions in people allergic to watermelon.

• Mouth allergy symptoms¹⁷

  Watermelon-specific IgE was found in some people, but tests could not predict who would get mouth symptoms after eating watermelon.

How it’s made and used

• Exercise performance¹⁵

  A single dose of watermelon juice before exercise did not improve performance in the people tested.

• Lycopene levels in older women²²

  In eight older women, a one-time drink of pasteurized watermelon juice raised blood lycopene three-fold.

• Blood levels after eating²⁴

  Eating lots of watermelon raised citrulline and arginine levels in people's blood.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.