Scientists have identified the world's healthiest vegetable, and it is more common than many might think. A study by the Centers for Disease Control and Prevention (CDC) ranked vegetables based on their nutrient density, and only one achieved a perfect score of 100: watercress.
Watercress Tops the Nutrient Density Chart
Watercress, a leafy green with a peppery flavour, outperformed Chinese cabbage, chard, beetroot greens, and spinach. It belongs to the Brassicaceae family, alongside cabbage, kale, radish, and mustard. Its Latin name, Nasturtium officinale, translates to "nose twister," likely referencing its pungent taste.
In Britain, watercress is a staple, widely available in supermarkets for around £1 a bag. It has been cultivated and consumed in the UK for centuries, and the Hampshire town of Alresford, known as "the watercress capital of the UK," even hosts a festival in its honour.
Health Benefits of Watercress
Dr Amy Lee, head of nutrition at Nucific, told Delish: "Watercress has a lot of health benefits. It’s high in vitamin A and potassium, more so than your typical lettuce." It is also rich in vitamin C, calcium, iron, vitamin E, vitamin K, and vitamin B6.
The CDC Study
The CDC report examined over 40 "powerhouse fruits and vegetables," defined as foods strongly associated with reduced chronic disease risk. Researchers compiled a tentative list based on existing scientific literature and dietary guidelines, then calculated a nutrient density score for each food.
They noted that cruciferous vegetables (watercress, Chinese cabbage, collard greens, kale, rocket) and green leafy vegetables (chard, beet greens, spinach, chicory, leaf lettuce) dominated the top half of the rankings, while yellow/orange vegetables, alliums, citrus fruits, and berries clustered in the bottom half.
How to Use Watercress
Watercress is commonly used in salads and soups, but it also makes an excellent pesto. A quick recipe can be prepared in less time than it takes to cook pasta.
CDC's List of Healthiest Fruits and Vegetables
The following table ranks foods by their nutrient density score (out of 100):
- Watercress: 100
- Chinese cabbage: 91.99
- Chard: 89.27
- Beet green: 87.08
- Spinach: 86.43
- Chicory: 73.36
- Leaf lettuce: 70.73
- Parsley: 65.59
- Romaine lettuce: 63.48
- Collard green: 62.49
- Turnip green: 62.12
- Mustard green: 61.39
- Endive: 60.44
- Chive: 54.80
- Kale: 49.07
- Dandelion green: 46.34
- Red pepper: 41.26
- Arugula: 37.65
- Broccoli: 34.89
- Pumpkin: 33.82
- Brussels sprout: 32.23
- Scallion: 27.35
- Kohlrabi: 25.92
- Cauliflower: 25.13
- Cabbage: 24.51
- Carrot: 22.60
- Tomato: 20.37
- Lemon: 18.72
- Iceberg lettuce: 18.28
- Strawberry: 17.59
- Radish: 16.91
- Winter squash (all varieties): 13.89
- Orange: 12.91
- Lime: 12.23
- Grapefruit (pink and red): 11.64
- Rutabaga: 11.58
- Turnip: 11.43
- Blackberry: 11.39
- Leek: 10.69
- Sweet potato: 10.51
- Grapefruit (white): 10.47
