Yes, it’s true. Multiple clinical studies have now confirmed that watermelon has all of these effects. Let’s take a quick look at the science.
Watermelon reduces blood pressure
A 2016 study from Brazil’s Federal University of Paraíba tested 40 adults for six weeks. Some of the subjects were diagnosed with hypertension (high blood pressure) while some were considered “prehyptertensive.” In other words, they either had high blood pressure or their blood pressure readings were on the higher side.
The researchers gave the subjects either a placebo or watermelon extract for six weeks. After the six weeks, those taking the watermelon extract saw their average systolic blood pressure rates go down from 137 to 126 mmHg. They also saw their diastolic rates go down from an average of 79.2 to 72.3 mmHg.
Those are significant reductions when it comes to blood pressure. And only after six weeks of the watermelon extract.
A 2014 study from the Florida State University found similar results and more. This study tested 13 people in a six-week crossover design study. This means they were tested twice, and those given the watermelon during the first testing were given the placebo during the second.
Again, the researchers found that extract significantly reduced systolic blood pressure. The watermelon also improved the subjects’ P1 and P2 heart measurements.
In another six-week 2014 study from Florida State University, 12 post-menopausal hypertensive women were given either a placebo or 6 grams per day of watermelon extract. After the six weeks, those who took the placebo were given the watermelon and those given the watermelon were given the placebo.
The researchers found again that the watermelon significantly reduced systolic blood pressure and diastolic blood pressure. The systolic reduction was an average of 10 mmHg, and the diastolic reductions averaged 7 mmHg.
Watermelon also decreases artery stiffness
This above 2014 study from Florida State University also found that the watermelon extract significantly reduced artery stiffness. This is also called arterial stiffness.
Watermelon reduces bad cholesterol
Low-density lipoproteins form a type of cholesterol called LDL. Too much LDL-c can produce artery damage because LDL-c tends to oxidize quickly and form free radicals. The oxidized LDL then damages the blood vessel walls.
In a 2016 study, researchers gave a placebo or 6 grams per day of watermelon extract to 43 patients with high levels of LDL-c. After 42 days, the patients were re-tested for their cholesterol levels.
The researchers found on average, those patients who took the extract saw their LDL-c levels go down significantly. These reductions were prominent among those with the T allele.
Watermelon also improves exercise recovery
Several studies have found that watermelon extract significantly improves recovery and decreases muscle soreness after high intensity exercise.
A 2017 study from Spain’s Santa Lucı́a University tested 19 men. They were tested with and without a watermelon supplement. The researchers found the extract allowed the men to recover faster with less muscle soreness after high intensity half-squat exercises.
A 2016 study from North Carolina’s Appalachian State University tested 20 cyclists. For two weeks, they were either given a placebo or 980 milliliters of watermelon puree for two weeks. After the two weeks, they completed a 75-kilometer biking time trial race.
The researchers then tested each of the cyclists again, switching those who took the placebo with those who ate the watermelon puree for another two weeks. They then participated in another 75-kilometer time trial.
This study didn’t find the times faster for the watermelon group. But it did find that inflammation levels were lower. They also found recovery times and muscle soreness levels were lower among those taking the extract. The watermelon cyclists also had stronger immunity.
Watermelon and nitric oxide
Watermelon contains a host of different vitamins and minerals, depending upon whether they are grown organically or not.
But they also contain key nutrients such as lycopene, l-citrulline, and l-arginine. l-citrulline in particular is known as a precursor to the body’s production of nitric oxide.
Other research has shown that eating watermelon or drinking watermelon juice boosts nitric oxide levels. Watermelon has also been shown to boost antioxidant activity in the body.
And studies that gave athletes watermelon with boosted levels of l-citrulline showed improved exercise performance.
We have discussed the effect of naturally boosting nitric oxide levels on athletic performance elsewhere. In particular, beets naturally boost nitric oxide levels. Now we can add watermelon to that list.
REFERENCES:
Martínez-Sánchez A, Alacid F, Rubio-Arias JA, Fernández-Lobato B, Ramos-Campo DJ, Aguayo E. Consumption of Watermelon Juice Enriched in l-Citrulline and Pomegranate Ellagitannins Enhanced Metabolism during Physical Exercise. J Agric Food Chem. 2017 Jun 7;65(22):4395-4404. doi: 10.1021/acs.jafc.7b00586.
Shanely RA, Nieman DC, Perkins-Veazie P, Henson DA, Meaney MP, Knab AM, Cialdell-Kam L. Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity. Nutrients. 2016 Aug 22;8(8). pii: E518. doi: 10.3390/nu8080518.
Figueroa A, Wong A, Kalfon R. Effects of watermelon supplementation on aortic hemodynamic responses to the cold pressor test in obese hypertensive adults. Am J Hypertens. 2014 Jul;27(7):899-906. doi: 10.1093/ajh/hpt295.
Massa NM, Silva AS, Toscano LT, Silva JD, Persuhn DC, Gonçalves Mda C. Watermelon extract reduces blood pressure but does not change sympathovagal balance in prehypertensive and hypertensive subjects. Blood Press. 2016 Aug;25(4):244-8. doi: 10.3109/08037051.2016.1150561.
Massa NM, Silva AS, de Oliveira CV, Costa MJ, Persuhn DC, Barbosa CV, Gonçalves MD. Supplementation with Watermelon Extract Reduces Total Cholesterol and LDL Cholesterol in Adults with Dyslipidemia under the Influence of the MTHFR C677T Polymorphism. J Am Coll Nutr. 2016 Aug;35(6):514-520
Cutrufello PT, Gadomski SJ, Zavorsky GS. The effect of l-citrulline and watermelon juice supplementation on anaerobic and aerobic exercise performance. J Sports Sci. 2015;33(14):1459-66. doi: 10.1080/02640414.2014.990495.
Figueroa A, Wong A, Hooshmand S, Sanchez-Gonzalez MA. Effects of watermelon supplementation on arterial stiffness and wave reflection amplitude in postmenopausal women. Menopause. 2013 May;20(5):573-7. doi: 10.1097/GME.0b013e3182733794.
Shanely RA, Nieman DC, Perkins-Veazie P, Henson DA, Meaney MP, Knab AM, Cialdell-Kam L. Comparison of Watermelon and Carbohydrate Beverage on Exercise-Induced Alterations in Systemic Inflammation, Immune Dysfunction, and Plasma Antioxidant Capacity. Nutrients. 2016 Aug 22;8(8). pii: E518. doi: 10.3390/nu8080518.
Ellis AC, Dudenbostel T, Locher JL, Crowe-White K. Modulating Oxidative Stress and Inflammation in Elders: The MOXIE Study. J Nutr Gerontol Geriatr. 2016 Oct-Dec;35(4):219-242.
Figueroa A, Sanchez-Gonzalez MA, Wong A, Arjmandi BH. Watermelon extract supplementation reduces ankle blood pressure and carotid augmentation index in obese adults with prehypertension or hypertension. Am J Hypertens. 2012 Jun;25(6):640-3. doi: 10.1038/ajh.2012.20.