Watercress has small, round leaves and edible stems that have a peppery, slightly spicy flavor. It is part of the Brassicaceae family of vegetables, which also includes kale, Brussels sprouts and cabbage.
Once considered a weed, it was first cultivated in the UK in the early 1800s but is now grown in watery beds throughout the world.
Watercress is low in calories but it is nutrient dense. It is ranked number one on the US Centers for Disease Control’s Powerhouse Fruits and Vegetables list.
One cup of watercress contains the following:
- Calories: 4
- Carbs: 0.4 grams
- Protein: 0.8 grams
- Fat: 0 grams
- Fiber: 0.2 grams
- Vitamin A: 22% of the Reference Daily Intake (RDI)
- Vitamin C: 24% of the RDI
- Vitamin K: 106% of the RDI
- Calcium: 4% of the RDI
- Manganese: 4% of the RDI
One cup of watercress provides over 100% of the RDI for vitamin K, a fat-soluble vitamin necessary for blood clotting and healthy bones. Vitamin K is a component of osteocalcin, a protein that makes up healthy bone tissue and helps regulate bone turnover. In one study, people with the highest intake of vitamin K were 35% less likely to experience a hip fracture than people with the lowest intake.
It is rich in vitamin A, also known as retinol, which is important for keeping your retinas healthy and your vision good. Getting enough vitamin A is also crucial to keeping your organs healthy because it’s critical for cell division.
Watercress is also rich in vitamin C, which supports your immune system, helps you heal from injuries, and supports healthy collagen production. Watercress also contains small amounts of vitamin E, thiamine, riboflavin, vitamin B6, folate, pantothenic acid, magnesium, phosphorus, potassium, sodium and copper.
Watercress contains lutein and zeaxanthin, which are antioxidant compounds in the carotenoid family. Antioxidants protect against cell damage caused by free radicals, which are harmful molecules that lead to oxidative stress. Lutein and zeaxanthin are essential for eye health and are linked to a lower risk of developing age-related macular degeneration and cataracts. The vitamin C in watercress is also associated with a lower risk of developing cataracts.
One study on the antioxidant compounds in 12 different cruciferous vegetables found over 40 unique flavonoids in watercress. Watercress outperformed all other vegetables in this study in terms of total amount of phenols and the ability to neutralize free radicals. Studies have linked the antioxidants in watercress to a lower risk of cancer, diabetes and heart disease.
Watercress contains the antioxidant alpha-lipoic acid. This compound can:
- lower glucose levels
- increase insulin sensitivity
- prevent oxidative stress-induced changes in people with diabetes
Studies on alpha-lipoic acid have also shown that it can decrease nerve damage in people with diabetes. The Food and Drug Administration (FDA) has approved supplementary alpha-lipoic acid to treat diabetic neuropathy.
Watercress contains potent anticancer compounds called isothiocyanates that have been shown to ward off several types of cancer. These glucosinolates are activated when they are cut with a knife or chewed. These compounds protect against cancer by safeguarding healthy cells from damage, inactivating carcinogenic chemicals and blocking the growth and spread of tumors. Isothiocyanates found in watercress have been shown to prevent colon, lung, prostate and skin cancers. Research indicates that the isothiocyanates and sulforaphane found in watercress suppress the growth of breast cancer cells.
If you don’t have enough calcium, magnesium, and potassium in your diet, you might be prone to high blood pressure. These minerals are thought to bring blood pressure down by releasing sodium from the body and helping arteries dilate. These minerals in supplement form will not provide the same health benefits as consuming them as part of a healthy diet. Watercress contains all three of these healthy minerals.
According to a 2013 study published in the British Journal of Clinical Pharmacology, foods containing dietary nitrates such as watercress have multiple benefits for blood vessels.
- Reducing blood pressure
- Inhibiting the buildup of platelets
- Preserving or improving endothelial dysfunction
- Decreasing the stiffness and thickness of your blood vessels.
* For individuals managing a blood clotting disorder with blood-thinning medications such as warfarin, it is important not to change their intake of vitamin K suddenly. This is because vitamin K has an essential role in blood clotting and can interfere with some medications, including warfarin.
* If a person does not refrigerate vegetable juice that contains nitrates, this may lead to a buildup of bacteria. These bacteria convert nitrate to nitrite and contaminate the juice. Too high levels of nitrite can be potentially harmful.
How to Buy
Select watercress with dark green and crisp leaves. If you want less spicy, look for upland cress.
How to Store
Most greens do not have a long shelf life. Watercress, which is 93% water, is no exception. Once harvested, this aquatic leaf is highly perishable and needs to be refrigerated.
To keep watercress fresh for up to 5 days, store it in the refrigerator in a deep bowl, upside-down with the stems submerged in cold water.
How to Cook
Before using watercress, wash it, then shake or spin dry.
Watercress can be used in a wide variety of dishes. To get the most benefits from its active antioxidant compounds, it’s best eaten raw or lightly steamed.
Here are some easy ways to add watercress to your diet:
- Sprinkle it on your salad.
- Stir it into your soup near the end of cooking.
- Use it to replace lettuce in a sandwich.
- Turn it into pesto by blending it with garlic and olive oil.
- Use it to top any dish.