Why is watercress healthy?

Often overlooked beside spinach, kale and rocket, watercress (Nasturtium officinale) is one of the most nutrient-rich vegetables you can eat. In fact, it achieved a perfect nutrient density score of 100 in a landmark study published in Preventing Chronic Disease, ranking it as the world’s most nutrient-dense fruit or vegetable. Researchers assessed 47 commonly consumed fruits and vegetables against 17 essential nutrients, and watercress came out on top.

This humble aquatic leafy green has been enjoyed for centuries for both its peppery flavour and its medicinal qualities. Naturally rich in vitamins A, C and K, folate, calcium and powerful plant compounds, watercress supports immune health, bone strength, healthy vision and the body’s natural antioxidant defences.

In this article, we’ll explore what makes watercress such a nutritional powerhouse, its impressive health benefits, how it compares with other leafy greens, and my favourite ways to cook with this remarkable vegetable.

There are leafy greens, and then there’s watercress.

According to research published by the US Centers for Disease Control and Prevention (CDC), watercress achieved the highest possible nutrient density score of 100, making it the most nutrient-dense fruit or vegetable evaluated.

Researchers developed a classification system for “powerhouse fruits and vegetables” (PFVs), ranking foods based on the amount of 17 essential nutrients they provide per 100 calories. Watercress came out on top.

For me, it’s always been one of nature’s quiet achievers.

Nutrition benefits

A member of the Brassicaceae family, alongside broccoli, cabbage, kale and rocket, watercress is naturally rich in vitamins K, C and A, as well as folate, calcium and potassium. It also contains glucosinolates, polyphenols and carotenoids, plant compounds that help protect cells from oxidative stress and support overall wellbeing. Naturally occurring dietary nitrates found in watercress may also help improve circulation and support healthy blood pressure by increasing nitric oxide production in the body.

Regularly including watercress in your meals can support bone health through its exceptional vitamin K content, while its abundance of vitamin C contributes to collagen production, immune function and healthy skin. The antioxidants found in watercress may help protect eye health, reduce inflammation and support healthy ageing. As part of a balanced diet rich in vegetables, watercress contributes valuable nutrients that help nourish the body from the inside out.

There are several types of watercress, although in Australia you’ll most commonly find the classic green variety.

The most common variety

The watercress sold in Australian supermarkets and greengrocers is common watercress (Nasturtium officinale), not to be confused with the colourful garden flower commonly called nasturtium (Tropaeolum majus) – scroll down.

Common watercress grows naturally in cool, clean, flowing water and is recognised by its small, rounded green leaves and hollow stems. This is the variety you’re most likely to find in Australia and the one featured in this recipe.

How they differ

• Common watercress is the classic culinary variety and the one featured in most recipes.
• Brown watercress has smaller leaves and a more intense peppery flavour.
• Upland cress isn’t a true watercress—it grows in soil rather than water but has a similar taste.
• Garden cress is another relative, often sold as sprouts or microgreens.

Nutritional differences

While all four belong to the Brassica (mustard) family and are rich in vitamins and phytonutrients, the CDC nutrient density ranking of 100 refers specifically to common watercress (Nasturtium officinale).

I picked up this bunch of watercress from the local market this morning. Alongside a knob of fresh ginger, it’s the beginning of one of my favourite winter soups—a simple combination that delivers remarkable flavour and nutrition.

What does watercress taste like?

Watercress has a distinctive peppery bite that comes from naturally occurring glucosinolates, compounds that are also found in broccoli, kale and rocket. When we chop or chew these vegetables, those compounds are converted into bioactive substances that have been widely studied for their role in supporting the body’s natural detoxification processes and cellular health.

But that’s only part of the story.

A handful of watercress provides vitamins A, C and K, along with folate, calcium, potassium and antioxidants including lutein and beta-carotene. Together, these nutrients support healthy vision, immune function, bone health, collagen production and protection against oxidative stress.

Because it’s over 90% water and incredibly low in kilojoules, watercress delivers an impressive nutritional return with very little energy intake—one of the reasons it earned its perfect nutrient density score.

My favourite ways to use watercress

Winter is when watercress really shines. I love to:

• Blend it into velvety soups with ginger, leek and potato.
• Toss it through warm grain salads.
• Add it to omelettes just before serving.
• Layer it into sandwiches instead of lettuce.
• Stir it through risotto or pasta at the very end of cooking.
• Enjoy it fresh in salads with citrus and walnuts.

The trick is not to overcook it. Like spinach, watercress wilts in seconds, preserving both its vibrant green colour and delicate nutritional profile.

As a chef and clinical nutritionist, I’m often asked which single vegetable deserves a permanent place in the shopping basket. Watercress is always near the top of my list. It’s affordable, seasonal, versatile and one of the simplest ways to boost the nutritional quality of everyday meals.

Sometimes the smallest bunches deliver the biggest health benefits.

Is watercress a nasturtium?

Watercress is Nasturtium officinale, a member of the Brassicaceae (mustard or cabbage) family. The genus name Nasturtium comes from the Latin words nasus (nose) and tortus (twisted), referring to the pungent aroma that “twists the nose” when the leaves are crushed.

This botanical name was given long before the brightly coloured ornamental nasturtiums became popular in gardens.

Why is it confusing?

The familiar garden nasturtium with orange, yellow and red flowers is not a true Nasturtium.

Its botanical name is Tropaeolum majus, and it belongs to an entirely different family, Tropaeolaceae. Early botanists gave it the common name “nasturtium” because its peppery leaves tasted similar to watercress.

So today we have:

What do they have in common?

Although they are unrelated, both plants contain glucosinolates and other sulphur-containing compounds that create their characteristic peppery flavour. These compounds are also found in broccoli, kale, rocket, mustard greens and cabbage, and are associated with many of the health benefits of cruciferous vegetables.

Which one is healthier?

Both are nutritious, but watercress is considerably more nutrient-dense. In the CDC’s landmark nutrient density study, watercress (Nasturtium officinale) achieved a perfect score of 100, ranking it as the world’s most nutrient-dense fruit or vegetable. Garden nasturtiums weren’t included in the study, although their edible flowers are rich in vitamin C and antioxidants.

A chef’s tip

Don’t confuse the two in recipes. If a recipe calls for watercress, it means Nasturtium officinale—the leafy green sold in bunches or bags. Garden nasturtiums (Tropaeolum majus) are best used as edible flowers and peppery garnishes rather than as a substitute for watercress.

Try these watercress recipes

Char siew with nectarines, ginger and watercress

Smoked salmon, corn and watercress salad

#watercress #foodasmedicine #chefsamgowing

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