The benefits of watercress

• Cancer . Certain compounds abundant in watercress , isothiocyanates, are believed to help limit the development of cancer ^{11-13 , 16,29} . They are particularly effective in preventing the development of lung cancer in smokers , by inhibiting the action of a carcinogenic substance present in cigarette smoke ¹⁵ . Watercress in the form of an extract (watercress juice) also protects cells against the onset of colorectal cancer ¹⁷ . Regular consumption of raw watercress (85 g or about 2½ cups) would have an anticancer effect by reducing the damage caused to the DNA of lymphocytes¹⁸ .
• Eye health . Several studies indicate that a regular intake of lutein and zeaxanthin is associated with a lower risk of macular degeneration, cataracts ^6,7 and retinitis pigmentosa ³⁰ . These two carotenoids, abundant in watercress, accumulate in the macula and retina of the eye ⁶ , thus protecting it from oxidative stress which could cause damage.

What does watercress contain?

Antioxidants

The main antioxidant compounds in watercress are the carotenoids and flavonoids . They are found in both the watercress and the watercress , in varying proportions. The antioxidants in watercress protect the cells of the body from free radical damage and prevent the development of cardiovascular disease, certain cancers and other diseases associated with aging ¹ .

Carotenoids . Several in vitro animal studies, as well as epidemiological studies, show that the consumption of foods rich in carotenoids is linked to a lower risk of developing certain types of cancer ^{2 , 32} , of developing diseases cardiovascular ^{33 , 34} and would have a preventive effect against high blood pressure ³⁵ . In addition, some carotenoids are precursors of vitamin A (that is, the body converts them into vitamin A, as needed).

Watercress is particularly rich in beta-carotene . One serving of raw garden cress (1 cup or 250 ml) contains twice as much carotenoid as watercress. For comparison, the carrot, recognized as one of the best sources of this carotenoid, contains 2 times more than the garden cress ³ . Thanks to its antioxidant power, beta-carotene could improve certain functions of the immune system and is associated with the prevention of cancer ^{4 , 5} . A high consumption of beta-carotene would also have a protective effect against the development of cardiovascular diseases ^{33 , 34}. However, since the consumption of beta-carotene supplements has not produced conclusive results, foods containing beta-carotene should be favored since they contain a host of other substances that may contribute to health benefits.

Garden cress is exceptionally rich in lutein and zeaxanthin ⁵ . A serving of raw garden cress (1 cup or 250 ml) contains 3 times more of these carotenoids than watercress and about 2 times more than a serving of raw spinach ³ . These compounds could help prevent certain cancers , including those of the breast and lung , in addition to participating in the prevention of cardiovascular diseases ⁶ . However, studies on cardiovascular health are still limited and sometimes contradictory ³⁶ .

Flavonoids . The main flavonoids of watercress are flavonols , including kaempferol and quercetin ^9,10 . Garden cress ranks among the foods richest in kaempferol, behind kale which contains twice as much, but ahead of chives, raw broccoli and chicory. Watercress contains 13 times less kaempferol than garden cress, but it contains quercetin ⁸ . It contains about 3 times less than onions, one of the main sources of quercetin in the diet ^{9 , 10} .

Glucosinolates

Like the majority of vegetables in the cruciferous family , watercress contains glucosinolates . It is said to contain more than broccoli, cauliflower and many varieties of cabbage (white, red, Savoy cabbage and bok choy) ¹⁴ . Garden cress contains almost 4 times more than watercress ¹⁴ , but their concentration can vary depending on environmental conditions (sun exposure, temperature). Glucosinolates have the capacity to transform into active molecules ( isothiocyanates ) when the food containing them is chopped, chewed or in contact with the intestinal bacterial flora ^{12, 15.37} . Several of these molecules would help limit the development of certain cancers ^11-13 . As cooking results in a significant loss of glucosinolates through the cooking water ²⁰ , it is preferable to consume the watercress, lightly cooked in a small amount of water or sautéed in a pan. The vegetable will thus retain all its benefits ¹⁹ .

Main vitamins and minerals

Precautions

Vitamin K and anticoagulants
Watercress, particularly the variety from Alen, contains a high amount of vitamin K, which is necessary, among other things, for blood clotting. People taking anticoagulant drugs (Coumadin®, Warfilone® and Sintrom®, etc.) should eat a diet with relatively stable vitamin K content from day to day. Watercress is part of a list of foods (asparagus, Swiss chard, broccoli, Brussels sprouts, spinach, etc.) that should be eaten moderately.

It is strongly recommended that people on anticoagulation therapy consult a dietitian-nutritionist or a doctor in order to know the food sources of vitamin K and to ensure a daily intake as stable as possible.

Oxalocalcic lithiasis and enteric hyperoxaluria
People at risk for urinary lithiasis (kidney stones made up of oxalate and calcium, also called kidney stones ) should limit their consumption of foods rich in oxalate . The same recommendation applies to people with enteric hyperoxaluria following intestinal disorders, such as inflammatory diseases of the small intestine (celiac disease, Crohn’s disease). Oxalates are found naturally in many foods and watercress contains large amounts. It is therefore preferable that these people avoid consuming it.

Contamination of wild watercress
Watercress, particularly that harvested from the wild, can be contaminated with liver fluke or Fasciola hepatica . It is a dangerous parasite that causes a liver disease called fascioliasis or distomatosis. In France, cases of contamination following the consumption of wild cress, and more rarely of raw commercial cress, have been reported in the scientific literature ²⁵ . In this country, it is estimated that around 300 people are infected annually after consuming raw wild cress ²⁶ .

In western Europe, watercress is the main source of human contamination with Fasciola hepatica ²⁷ . Cases have also been reported in India, Iran, North Africa and some countries in South America. In North America, this type of infection is rather rare, only a few cases having been documented so far ²⁸ .

The watercress and garden cress can be used interchangeably in recipes.

• As a garnish in sandwiches or boiled eggs with mayonnaise.
• As a salad , alone or with other seasonal vegetables. For an original salad, grind mustard seeds (and, if possible, watercress seeds) with red, black and white peppercorns. Add oil and vinegar or lemon juice to make the dressing.

• In soup . Sauté leek and potatoes in butter or olive oil. Add vegetable or chicken broth and cook for about 20 minutes. Add a bunch of watercress and, if desired, a little cream. Go to the blender. This soup is eaten hot in winter and cold in summer.
  Variations  : you can replace the potatoes with squash, Jerusalem artichokes, parsnips, etc. You can also add tuna, salmon, shrimp or any other fish to the soup. Reheat for a few minutes and serve.
• In soufflés , quiches or pies.
• Chop and add it to the mashed potatoes .
• In England, it was traditional to eat one or two leaves between two services to clean the palate .
• In Chinese , in stir-fries.
• In sauce to accompany meat or fish. Switch to the watercress, olive oil or other oil of your choice, lemon juice and garlic. If desired, add other herbs.
• In pesto (watercress, fresh basil, olive oil and grated parmesan), to season pasta, potatoes, rice, etc. For a slightly more sophisticated pesto, add spinach and arugula leaves.
• In shakes ( smoothies ), for example: watercress, pear and melon; watercress, apple and kiwi; watercress, blueberries and pineapple.
• Stuff it with poultry.
• In a salsa , with hot pepper, sweet pepper, cucumber and tomato. Coarsely chop the ingredients and serve them in a bowl. Dip blue corn chips or serve over grilled chicken.
• Make it a dip with yogurt, avocado, tomato, cumin, coriander. Blanch the watercress for 1 minute in boiling water and let cool before blending it with the other ingredients.
• Japanese-style marinated . Blanch the watercress for 1 or 2 minutes in boiling water, drain and let cool. Press to remove the excess water and then marinate it for half an hour in a mixture of dashi or another broth, soy sauce and mirin. Serve in its broth with sesame seeds or dry roasted pine nuts in a pan. Or simply season the watercress with sesame oil.

The word ”  watercress  ” appeared in the French language in 1130. It comes from the French kresso , which means creeping.

Alénois is a distortion of “orlénois”, a word derived from Orléans, the region where this plant was once cultivated. He appeared in the French language in the XIII ^th  century, and is only used in the phrase “garden cress”.

However, “watercress” is also used more broadly to designate several other plants of the brassicaceae family belonging to various botanical genera, notably Barbarea and Cardamine . Their fleshy stems and their more or less large leaves are edible. However, watercress ( Nasturtium officinale ) is by far the most consumed plant.

It is unclear where the garden cress comes from. Some speak of Ethiopia, others of West Asia. But it is believed to have been consumed for a very long time by humans. Egyptians, Greeks and Romans knew it and appreciated its spicy flavor. They also lent it multiple medicinal properties . It spread very quickly in Europe as well as in the rest of the world. Grown almost everywhere in gardens, it is rarely the subject of large-scale cultivation, so that it is only occasionally found on the market. Many types and cultivars are known, including one with curly leaves and one with broad leaves.

Little is known about the origin of watercress, except that, in its natural habitat – running water, streams, springs, ditches – it grows in the wild on a vast territory from Europe. to Central Asia. It has naturalized in many other places around the world, including the United States and Canada. It is said to be one of the most ancient leaf vegetables. In France, from the XIII ^th  century, its natural environment is aménageait to increase production. The culture itself will only begin in the XVIII ^th  century, Germany. It is especially popular in Britain, where since the XVII ^th  century, it is considered an excellent detoxing. In this country, the spring cress cure still has many followers.

The cultivation of watercress is similar to that of rice: it is produced in shallow basins – or watercress – which are periodically dried and then flooded. The plant draws its nutrients mainly from water, which must be rich in minerals, relatively cool (10 ° C or 11 ° C), and of high purity . In commercial crops, this water is also subject to rigorous health surveillance. Otherwise, people who eat watercress are at risk of contracting fascialosis, a parasitic disease that can have serious consequences.

Almost everywhere it is produced, the harvest is done by hand in relatively difficult conditions. To counter this problem, we have undertaken for a few years to cultivate it under greenhouse, in hydroponics .

Everything is eaten in watercress and garden cress: leaves, stems , flowers , young pods and seeds.

Garden cress

In Europe, seeds of garden cress and mustard seeds are germinated together in a proportion of two to one. Simply sow them very tightly in a shallow container filled with potting soil and placed on the edge of a south-facing window. Keep the soil moist , but not soggy. The seeds will germinate very quickly and, after 10 days, you can harvest with scissors the young green and spicy shoots . Repeat the operation regularly, especially during winter.

In the garden, watercress can be sown very early in the spring , even when it is still freezing. However, it is recommended to protect it with an agrotextile fabric if the temperature drops too low. Sow every two or three weeks to have young plants all summer and fall. With age, the plant becomes leathery and fibrous. We can then let it rise and harvest the young pods, perfectly edible, or wait until the seeds are ripe to use them as a condiment or use it for subsequent sowing.

Watercress

In our climates, this perennial is usually treated as an annual. Watercress is usually grown in water ponds , but can be grown in the garden provided the soil is moist. See the culture technique proposed in.

Like many monocultures, watercress can be a source of pollution. In the south of England, the rapid multiplication of watercress farms in recent years has greatly contributed to the pollution of rivers . One of the largest watercress farms in the country is accused of contributing to the pollution of the Bourne, a small stream once celebrated for its water of great purity. Pesticides, zinc and chlorine, which are widely used in this crop, are pointed out. In France, it is believed that the pollution of the Juine river, in Essonne, would be caused, at least in part, by the rinsing water used to disinfect the watercress culture tanks. This water is loaded with residues of powerful products, such as formalin. The trend towards growingorganic watercress , considered less polluting, grows, but nevertheless remains marginal.