Watermelon contains an amino acid called L-citrulline.

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What says “summer” more than freshly cut watermelon? A classic addition to any picnic or barbecue, watermelon is a summertime favorite. But is watermelon good for you?

In terms of health benefits, it has a lot going for it. It’s sweet and tastes like a treat, but it’s also low in calories, high in fiber, hydrating, and rich in nutrients. And watermelon may even help to lower your blood pressure, too.

Watermelon contains an amino acid called L-citrulline. In the body, L-citrulline is converted into L-arginine, an amino acid that is needed for the production of nitric oxide, a potent blood vessel dilator._[1]

When nitric oxide is produced, our blood vessels dilate and our blood pressure goes down. Studies show that when you give the body L-arginine, both systolic and diastolic blood pressure readings decrease significantly._[2]

Because L-citrulline is efficiently converted to L-arginine, supplementing with L-citrulline also helps to increase nitric oxide production._[1,3] This compound also seems to help lower blood pressure in other ways—by decreasing, for example, the oxidation of lipoproteins (like LDL cholesterol) and improving endothelial dysfunction._[4]

Is Watermelon Good for You and Your Blood Pressure?

Several studies have looked at what happens to blood pressure readings when people consume extracts from watermelon. In one study on obese adults with prehypertension or hypertension, researchers gave participants a ground-up watermelon preparation (containing 6 grams of L-citrulline/L-arginine) or a placebo daily for six weeks. At the end of the study, they found that when people ate watermelon extract, their ankle and brachial systolic blood pressure, diastolic blood pressure, and mean arterial pressure were significantly reduced._[1]

A similar study on postmenopausal women with hypertension found reduced aortic blood pressure readings and reduced stiffness in the arteries when watermelon extract was consumed._[5] Watermelon also protects against blood pressure increases that occur when a person is exposed to cold temperatures._[6]

While most of these studies have been small in size, the evidence is growing that favors watermelon as an effective blood pressure lowering food.

Eat More Watermelon This Summer

Now that you know the answer to the question, “Why is watermelon good for you?” you don’t need to shy away from this popular fruit this summer. Enjoy slices as part of a picnic or cubed pieces in a refreshing fruit salad. Or spoon it right out of the melon as a healthy and tasty dessert alternative.

For other techniques to lower blood pressure naturally, such as “How to Use Breathing Exercises to Lower Blood Pressure,” read our extensive collection of posts on the topic here.

Share Your Experience with Watermelon

Do you eat watermelon? How do you like to prepare it? What other summertime foods do you eat to help lower blood pressure? Share your experience in the comments section below.

Originally published in 2015, this post has been updated.

[1] Am J Hypertens. 2012 Jun;25(6):640-3.

[2] Am Heart J. 2011 Dec;162(6):959-65.

[3] Am J Hypertens. 2011 Jan;24(1):40-4.

[4] Immunol Endocr Metab Agents Med Chem. 2013 Sep;13(3):214-220.

[5] \Menopause. 2013 May;20(5):573-7.

[6] Am J Hypertens. 2014 Jul;27(7):899-906.