Watermelon compounds and health effects in lab and animal studies
What it found
Watermelon contains lycopene, citrulline and polyphenols that have been tested for heart, diabetes, ulcer, antioxidant and cancer effects.
Most evidence comes from lab and animal studies, with some small human studies.
What they found
Studies in people
Heart and blood pressure
In obese adults, eating watermelon daily for four weeks led to reductions in body weight, body mass index, waist-to-hip ratio, and blood pressure. It also lowered triglycerides, LDL cholesterol, and a marker of oxidative stress, and increased antioxidant capacity.
Animal and lab studies
Ulcerative colitis
In high-fat fed mice with ulcerative colitis, watermelon supplementation improved colon crypt structure and increased nitric oxide levels. It also reduced a marker of DNA damage called 8-OHdG.
Antioxidant activity
Watermelon contains lycopene, polyphenols, and other compounds that show antioxidant activity in lab tests. Red-fleshed watermelons had higher levels of phytochemicals and antioxidant capacity than yellow-fleshed ones.
Studies in people and animals
Diabetes and obesity
In Zucker diabetic fatty rats, watermelon juice supplementation raised arginine levels and decreased glucose, free fatty acids, homocysteine, and methylarginines. In humans, watermelon juice improved arterial function and reduced blood pressure in obese middle-aged adults with pre-hypertension.
Cancer cell effects
In lab tests, lycopene inhibited the growth of human breast and endometrial cancer cells. Watermelon leaf extracts reduced the growth of cervical and breast cancer cell lines, and a compound from sprouts called phytol inhibited leukemia and lung cancer cell growth in mice.
What the authors conclude
“Moreover, being the functional food intake of watermelon can prevent the onset of various disorders in humans.”
Also in their conclusions
- They conclude that watermelon contains diverse phytochemicals with pharmaceutical importance, mainly citrulline, lycopenes, and polyphenols.
- They state that further studies are required to extract active phytochemicals and investigate their molecular mechanisms to extend their use in nutraceutical industries.
- They advise that intake of watermelon as a functional food can prevent the onset of various disorders in humans.
How it was done
The authors wanted to review the nutraceutical potential of watermelon and its phytochemicals for treating various ailments, as watermelon has been used traditionally and is rich in pharmaceutically valuable compounds.
They reviewed published studies on watermelon and its extracts, including lab tests on cells, animal experiments in rats and mice, and some human studies. The human studies included obese adults with pre-hypertension and obese adults, but the review does not state how many people were studied or for how long, except one study where watermelon was consumed daily for four weeks.
What it can’t tell you
- Many of the findings come from animal or lab studies, so they cannot show what happens in people.
- The human studies in this review are small and do not prove that watermelon causes the health improvements seen.
- The review does not provide details on how long most human studies lasted or how many people took part.
Who paid
- Conflicts
- These authors have declared no conflict of interest.
- Authors work at
- National Institute of Horticultural and Herbal Science, Korea
The paper
- Title
- Versatile Nutraceutical Potentials of Watermelon-A Modest Fruit Loaded with Pharmaceutically Valuable Phytochemicals
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Manivannan A, Lee ES, Han K, Lee HE, Kim DS (2020). Versatile Nutraceutical Potentials of Watermelon-A Modest Fruit Loaded with Pharmaceutically Valuable Phytochemicals. Molecules (Basel, Switzerland). doi:10.3390/molecules25225258Free full textPubMed 33187365DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error