Watercress can be found in various locations such as forests, ditches, and rocky cliffs… It adapts well to tropical environments, making it common in any tropical country. Watercress can be prepared in many different dishes, which contributes to its popularity. However, few people pay attention to the nutritional value and health benefits of watercress.
Watercress is scientifically known as Peperomia Pellucida. Botanically, the plant belongs to the Piperaceae family (pepper), which comprises about 5 genera and 1,400 species. The Peperomia genus represents nearly half of the Piperaceae family. P. Pellucida can grow to a height of approximately 15 to 45 cm, with light green, glossy, succulent, heart-shaped leaves. This species thrives in the rainy season (typically in spring) and grows best in loose, moist soil under tree canopies.
Many countries around the world regard watercress as a “miracle herb” for treating various ailments. In the Philippines, people use watercress leaves as poultices to treat boils and ulcers. The Chinese and Brazilians use watercress juice to address conjunctivitis.
Today, in some places, this vegetable can be more expensive than meat, with prices ranging from 70,000 to 80,000 VND per kilogram, and in some cases, it can exceed 100,000 VND per kilogram.
Watercress thrives during the rainy season.
Watercress is a type of food but is often recognized as an herb used for medicinal purposes. Ethnobotanical data from Bolivia, recorded by the Altenos indigenous people, notes that the entire plant is crushed, mixed with water, and heated. This mixture is said to stop bleeding. Other similar documents suggest that decoctions of the roots are used to treat fevers, while other parts are applied topically for abdominal pain, abscesses, acne, colic, fatigue, gout, headaches, kidney disorders, and rheumatism, and even for treating breast cancer.
Medicinal properties may vary across different geographic regions. In northeastern Brazil, the plant is used to lower cholesterol. In Guyana, watercress has been utilized as a diuretic and to treat proteinuria. In the Amazon region, it is used as a cough remedy, diuretic, emollient, and for treating arrhythmias. According to traditional Chinese medicine, the plant has a bitter taste and neutral properties, beneficial for clearing heat and detoxifying, dispelling wind, invigorating blood circulation, and resolving blood stasis, commonly used for treating respiratory infections, appendicitis, and various digestive disorders.
A chemical study focusing mainly on the essential oils of the plant has identified 71 compounds from the essential oils of 10 Piperaceae species. Watercress contains Carotol (13.41%), which is the main hydroxylated sesquiterpene. Other active compounds such as arylpropanoids exhibit antifungal properties, and peperomin has cytotoxic or anticancer activity in vitro. The nutritional components we absorb from watercress include 24 calories, water (92%), and vitamins and minerals (8%). Consuming watercress may cause symptoms similar to asthma in individuals allergic to this plant due to its mustard-like odor.
Some cases of eating watercress may show breathing difficulties similar to asthma.
Some highlighted benefits of watercress include:
- Hydrating effect: Given that a large portion of the vegetable is water and watercress has neutral properties, it is an excellent choice for cooling.
- Pain relief/anti-inflammatory: One study reported that the anti-inflammatory activity of watercress may vary depending on the plant’s developmental stages. Greater anti-inflammatory effects were noted during the vegetative stage and early flowering or throughout winter and spring. Experiments on mice have demonstrated the pain-relieving ability of watercress, with pain inhibition ranging from 50% to 78%. Differences may arise from the extraction methods, climatic conditions, and plant origins. Therefore, eating watercress is commonly used in treating fevers, coughs, colds, headaches, and arthritis.
- Antibacterial effect: The crude methanolic extract in watercress exhibits broad-spectrum antibacterial activity. The complete extract from watercress inhibited the growth of chloroquine-resistant Plasmodium falciparum Indo by 95% in vitro at 100 mg/mL and Plasmodium vinckei petteri malaria by 78% in vivo at 1,000 mg/kg. Monoterpenoid derivatives from Peperomia galioides have shown toxicity against the promastigote forms of Leishmania braziliensis, Leishmania donovani, and Leishmania amazonensis at a concentration of 25 mcg/mL, causing complete lysis of the parasites at 100 mcg/mL.
- Anticancer effect: The extracts from watercress inhibit the growth of certain cancer cells. This suggests that watercress could be a potential dietary supplement for cancer treatment.
- Antioxidant effect: A study on the extracts of watercress indicated that the plant has a strong scavenging activity against free radicals, suggesting that pansit-pansitan is a good natural antioxidant.
- Uric acid reduction effect: A study conducted on mice showed that the blood uric acid level decreased by 44%, while those given allopurinol saw a 66% reduction. These results indicate that watercress may contain compounds that could be used as alternatives to allopurinol for controlling blood uric acid levels.
- Depressive activity: In a study conducted on mice in Bangladesh, following stimulation with nikethamide and injection of watercress extract, it was found that the extract exhibited depressive activity. However, this is dose-dependent, allowing for its use in treating excessive stimulation.
- Nourishing nutrients: The minerals found in watercress, such as potassium and magnesium, are beneficial for cardiovascular health and blood pressure.
- Support for bone healing: With the mineral content in watercress, wrapping it around a broken bone can expedite the healing process, aiding in faster recovery.
- Treatment for rheumatoid arthritis: Juice extracted from the stems and fresh leaves of watercress, consumed as a decoction in the morning and evening, can help improve rheumatoid arthritis.
Eating watercress has no reported side effects for most individuals. However, there is not yet sufficient research to confirm its safety for pregnant or breastfeeding women or infants. Therefore, caution is advised before using watercress for any purpose.
