Watercress (Nasturtium officinale) is a leafy green vegetable often used in salads, sandwiches, and other recipes. The semi-aquatic plant is native to Europe and Asia but now grown all over the world. Watercress is one of the oldest known vegetables consumed by humans. As its name implies, watercress is mostly water. Nonetheless, there are a host of health benefits to be gained from this refreshing green.

Watercress Nutrition Facts

This nutrition information is provided by the USDA for 1 cup (34g) of chopped watercress.

Calories: 3.7

Fat: 0g

Sodium: 14mg

Carbohydrates: 0.4g

Fibre: 0.2g

Sugars: 0g

Protein: 0.8g

Carbohydrate

As its name implies, watercress is primarily made of water. Even in a full cup, there's a minimal amount of carbohydrate, protein, or fat. Per serving, watercress provides less than 1/2 gram of carbohydrates, 50% of which is fibre.

Fats

Watercress is considered a fat-free food.

Protein

The most common macronutrient in watercress is protein, but it only contains 0.8 grams per cup.

Vitamins and Minerals

Watercress provides potassium, calcium, magnesium, vitamin A, vitamin K, and folate, along with trace amounts of several other micronutrients.

Health Benefits

The high water and nutrient content of watercress promotes good health and reduces the risk of several diseases. Here are some reasons to add watercress to your grocery list.

Protects Eyesight

Watercress provides vitamin A, with 54.4 micrograms of retinol equivalents per cup. The daily requirement is 700–900 micrograms for most adults, so 1 serving of watercress provides about 6%–7%. Of particular note is the high level of two specific carotenoids, lutein and zeaxanthin, which are known to accumulate in the retina. These antioxidants help protect against age-related macular degeneration, a common cause of vision loss.

Promotes Hydration

It's not only the beverages you drink that keep your body hydrated. Several fruits and vegetables are also good sources of water, effectively helping to prevent dehydration. In 34 grams of watercress, there are 32.3 grams of water, meaning watercress is 95% water.

Maintaining adequate hydration helps boost energy levels, prevent headaches, and promote digestion. All of our body systems depend on water to function properly, so the combination of eating water-rich foods and drinking enough water are both important daily habits.

Supports Healthy Weight Management

Watercress is a non-starchy vegetable, with a very low energy density. That means you can eat a large volume of watercress and other leafy greens without the risk of exceeding your daily calorie requirement. In a 2011 study, researchers found that increasing fruit and vegetable consumption by just one serving per day led to a 4-pound weight loss over six months.

Vegetable intake has also been associated with lower rates of weight gain with age. Watercress fits perfectly into a healthy meal plan geared toward weight loss.

Lowers Risk of Cancer

Green leafy vegetables, like watercress, are a top food choice for fighting cancer. Consuming 2–3 servings of leafy greens per week is associated with a lower risk of breast, skin, and stomach cancer. Watercress can also help you get enough folate, which is essential for the proper replication and repair of DNA. Filling your plate with a variety of colourful fruits and vegetables protects against several forms of cancer.

Strengthens Bones

A cup of watercress has almost a full day's value of vitamin K. Higher intakes of vitamin K have been linked to better bone density and lower risk of hip fracture. Vitamin K assists with the carboxylation of osteocalcin, one of the main proteins in bone. Although this role does not prove vitamin K's impact on osteoporosis risk, it seems that watercress could be beneficial (especially since it also provides some calcium).

Allergies

Watercress is considered a common allergen, although food allergies are possible to any type of food. The vast majority of food allergies are caused by eggs, milk, peanuts, tree nuts, fish, shellfish, wheat, and soy—not vegetables. If, however, you suspect an allergy to watercress, you can meet with an allergist to review your concerns and possibly get a skin prick or blood test for a proper diagnosis.

Adverse Effects

The vitamin K in watercress has the potential to interfere with blood-thinning medications, like Coumadin (warfarin). It is generally recommended to maintain a consistent intake of foods high in vitamin K while taking blood thinners so your doctor can determine an effective dosage of medication that's based on your typical dietary habits.

Varieties

Watercress is related to two similar vegetables: garden cress (also called curly cress and pepper cress) and upland cress (also known as winter cress, broadleaf cress, or creasy greens). Garden cress has curly leaves and a similar peppery taste as watercress. Upland cress has small, square leaves.

When It's Best

Watercress can be purchased at the supermarket or farmers markets. Look for fresh, bright leaves that are free of damage. Avoid signs of yellowing or wilting. If picking your own, watch out for a similar-looking plant called "fool's cress" which is actually poisonous marshwort.

Storage and Food Safety

The same food safety rules apply to watercress as other leafy greens. Store unwashed watercress in the refrigerator until ready to use. Because it's delicate, don't put watercress in the refrigerator crisper. Instead, place a bunch of watercress in a cup of water with the stems down in the fridge (like a bouquet of flowers).

Before handling watercress, wash hands well with soap and water. Remove any damaged or rotten areas. Watercress that's labelled "pre-washed" or "ready to eat" does not need to be washed again before eating. If this label is not present, rinse watercress leaves under running water just before eating. You can also immerse watercress in a clean bowl filled with cold water to clear off dirt and bacteria. Pat or spin dry and enjoy.

How to Prepare

Watercress has a mild, peppery taste. Popular watercress salads include apple, avocado, and other fresh greens like arugula, spinach, or mache.

You can also enjoy watercress in soups, potato dishes, on top of deviled eggs, added to spring rolls and wraps, or in your favourite stir-fry recipe.