Watercress is a dark, leafy green that is said to be an excellent source of minerals.
Consuming all types of fruits and vegetables, including watercress, has been linked to better overall health.
Health experts say the benefits of eating watercress are many, and that one can eat watercress every day. Locally, this green leaf wonder vegetable can be found in some local supermarkets and markets.
Joseph Uwiragiye, the head of the nutrition department at University Teaching Hospital of Kigali (CHUK), says watercress provides a good amount of vitamins and proteins.
He says that watercress is rich in vitamin A (via beta-carotene) and vitamin C, and a source of folate, calcium, iron as well as vitamin E.
He adds that it also contains a variety of phytochemicals, including glucosinolates, lutein, flavonoids, and hydroxycinnamic acids, and has significant antioxidant activity in vitro.
Erick Musengimana, a nutritionist at Rwanda Diabetes Association-Kigali, says that with the presence of antioxidants, watercress has anti-cancer properties which help inhibit prostate, colon, lung, and breast cancer.
The leaf, he says, also helps maintain cardiovascular health, eliminates free radicals, and prevents cell damage.
He says that watercress, along with other fruits and vegetables, is a great source of fibre to nurture our microbes, but it also has one of the highest levels of antioxidants.
Musengimana explains that gut bacteria get their energy from fermenting fibre in the food we eat (as well as probiotics like fermented foods).
“These microbes are essential in our long-term health, from developing our immune system, to protection from bowel disease, and lifting our mood,” he says.
He adds that gut bacteria has an important role activating these antioxidants before we can use them for essential daily detox to reduce DNA damage from the many toxins we’re constantly exposed to — either in the environment or those from metabolic processes within our body.
Studies show that 100g of watercress provides a quarter of the recommended daily amount of calcium which is needed to reach maximum bone density while growing.
And after one has stopped growing, calcium is needed to maintain bone density.
Also, he says, vitamin K is a key nutrient in bone density and watercress is a vitamin K powerhouse.
Studies also reveal that vitamin K is not as easily absorbed from plants as it is from food of animal origin, but 100g of watercress contains four times our recommended daily intake making it a very rich source of the valuable vitamin.
Uwiragiye says watercress, like beetroot, is rich in nitrates. High-nitrate foods have the potential to enhance our own supply of nitrous oxide, and, therefore, help regulate blood pressure, which in turn optimises oxygen use during sport.
Nutritionists point out that watercress contains high levels of iron, unusual in vegetables and necessary to convert energy in our food to be active and essential for growth and development.
Iron in vegetables, however, is impossible to be absorbed unless vitamin C is also present to change the iron into the same form that’s easy to absorb from red meat.
80 grams of watercress contain more vitamin C than an orange of the same weight, and so it means that the iron in watercress is absorbed easily.