Review shows that the fruit is the main dietary source of L-citrulline, a substance linked to the protection of blood vessels
Known for hydrating on hot days, watermelon goes far beyond its high water content. A narrative review of 124 studies, conducted by researchers from the (Federal University of Rio de Janeiro) and indicates that both the pulp and the skin of the fruit contain compounds with cardioprotective potential, especially L-citrulline, associated with vasodilation and blood pressure regulation.
L-citrulline is an amino acid that received its name precisely because it was identified for the first time in watermelon, whose scientific term is Citrullus lanatus. In our body, L-citrulline can be converted into L-arginine, crucial for the synthesis of nitric oxide.
An ally of cardiovascular health, nitric oxide is a gaseous compound, derived from endothelium, cellular tissue that covers the inside of blood vessels. In the body, this substance contributes to vasodilation, regulation of blood pressure and protection against inflammatory processes. It also acts against oxidative stress, preventing the oxidation of LDL cholesterol. This process reduces the formation of plaque in the arteries and, consequently, problems such as atherosclerosis, heart attack and stroke.
Watermelon is considered the best food source of L-citrulline and, the more ripe it is, the more it accumulates the compound. “The content in the rind of fresh red watermelon varies between 60 and 500 mg/100g, while the pulp contains 40 to 160 mg/100g”says nutritionist Diego Baião, researcher at UFRJ and 1st author of the review.
The problem is that, to reach the minimum effective dose of the substance, which is 2 to 3 grams per day, it would be necessary to consume 1 to 3 kg of peel or 3 to 5 kg of pulp per day. That’s where science and technology can help. “The production of a powder would allow a greater quantity of the substance and other bioactive compounds to be concentrated, in addition to facilitating transport and storage”suggests Baião.
Vitamins, minerals and other riches
But watermelon is not made up of L-citrulline alone. “Pulp and peel stand out for their low energy density and supply of carbohydrates, vitamins and minerals, while seeds contain proteins, lipids and vitamin E”says nutritionist Ana Clara Ledezma Greiner de Souza, from .
The red version, much more common, accumulates lycopene, and yellow watermelons offer beta-carotene. Both are representatives of carotenoids, a family of pigments with powerful antioxidant action and which also stand out in studies for their cardioprotective action.
There is yet another group of phytochemicals that collects evidence of heart-healthy effects: phenolic compounds. These are substances that Botanists call them secondary metabolites, produced to protect the species, preserving the plant’s structures from climate variations, as well as sun and wind.
In addition to offering protective compounds, the fruit helps to refresh and hydrate the body like few others. In fact, historical reports reveal that it was used to quench thirst when crossing the deserts in Africa, its continent of origin.
“Consumption can contribute to maintaining water balance, especially in hot climates and during physical activity”highlights Souza. This is because, in addition to water, watermelon contains electrolytes such as potassium and magnesium. Thanks to the sugars diluted in the fruit, it has good palatability and allows ingestion in larger volumes without significant caloric impact.
Even with so many attributes, however, watermelon is not miraculous. Scientific evidence indicates that no food, in isolation, is capable of preventing or treating diseases. “Healthy eating is built on balance, variety and the interaction between different nutrients, always considering each person’s individuality and lifestyle habits”highlights nutritionist Bárbara Valença Caralli Leoncio, also from Einstein.
In nature or in preparations
The best way to include watermelon in your daily life is in the in nature. “This way, nutrients are better preserved”, says Ana Clara Souza. Its succulent slices can be served for breakfast, as a dessert option for lunch and dinner or for snacks between meals.
If the idea is to prepare recipes, it’s worth opting for juice, smoothiepopsicle and even salad. “Pairs with leaves, fresh vegetables and cheeses”says Souza. You can also use the peel. “It is used to make jellies and preserves, while the seeds can be roasted and consumed as a snack nutritious”says Diego Baião.
A tip when purchasing is to prefer the whole fruit. Although there are watermelon options sold in pieces, you need to be very careful — if there is a lack of hygiene when handling the knife used for cutting, for example, contamination by harmful microorganisms can compromise its benefits.
With information from .
