Nasturtium, raw (organic?)

Both the leaves and flowers of the nasturtium ( Tropaeolum majus L. ) are suitable for eating raw, seasoning and garnishing. If you grow it yourself, it is guaranteed to be organic .

Use in the kitchen

Can you eat nasturtiums? All parts of the nasturtium are edible. The leaves have a slightly sharp, cress-like taste. Among the edible flowers, nasturtiums are one of the pioneers on the plate. Nasturtiums are not only very decorative, they can also be used wonderfully in the kitchen. Whether on salad or bread and butter, fresh cress leaves add a pleasant spiciness to any dish. In summer, the flowers of the nasturtium, red, yellow or orange, are a joy for the eye and the stomach. You can give spicy dishes a special touch with the beautiful nasturtium flowers. In autumn, when the flowers slowly turn into seeds, you can harvest the seed capsules while they are still green. Preserved in vinegar or salt, the 'false capers' made from nasturtium seeds go excellently with salads. For example: Colorful autumn salad with nasturtiums, pumpkin and spinach or as a substitute for real capers and something a little more sophisticated: herb-caper dumplings with carrot puree in white wine sauce .

Nasturtium recipes are often used in vegan raw food. The spicy taste of nasturtiums goes well in salads, as a spread or pesto. The leaves are particularly suitable for potato salad, filled with rice and vegetables, in vegan herb butter or as a vegan cream soup.

Can you eat nasturtium seeds raw? Ripe seeds can be dried and used likepepper . To do this, halve the seeds and leave them to dry in a dark place for two days. Then put the seeds in a pepper mill or crush them with a mortar.

In the case of the tuberous nasturtium ( Tropaelum tuberosum ), the tubers are mainly used, similar to potatoes . The roots of the large nasturtium are not suitable for consumption, but they are not poisonous either.

Vegan pesto recipe with nasturtium

Ingredients: 50 g nasturtium leaves, 4-5 nasturtium flowers, 4 basil leaves, 1 garlic clove, 40 g sunflower seeds, 10 g almonds, 10 g walnuts, 1 teaspoon lemon juice, 80 ml rapeseed oil, ½ teaspoon sea salt, ¼ teaspoonground pepper .

Preparation: Wash the flowers and leaves and pat dry with a kitchen towel. Put all the ingredients in a high-performance blender and mix finely. If you use a hand blender, it is worth pressing the garlic clove first. The vegan pesto tastes great on wholemeal pasta, for example.

Vegan recipe for nasturtium seeds as 'false capers'

Ingredients (1 jar): approx. 2 handfuls tender green seed pods of nasturtium (organic, raw), 75 ml white balsamic vinegar (organic), salt, 130 ml water .

Preparation: Carefully separate the seed pods (usually three are stuck together). Wash them well and place them in a screw-top jar while they are still slightly damp. Sprinkle the 'capers' with salt and shake the jar until they are all well covered with salt. The 'fake salt capers' are left to drain in the fridge for a week, during which the volume is reduced by half. Then wash off the salt and put the capers back in the clean jar. For a long shelf life, boil the jar and lid. Boil the vinegar and water briefly. Pour the mixture over the seed pods so that they are all covered. Then leave to steep for two weeks.

Vegan recipes with nasturtium (raw) can be found under the note: " Recipes that have the most of this ingredient ".

Purchasing - Storage

Nasturtiums are best grown at home. The tasty herb is easy to grow in the garden, on the balcony or as a houseplant. Nasturtiums are in season in Central Europe from June to October . They are only available in exceptional cases at major retailers such as Coop, Migros, Denner, Volg, Spar, Aldi, Lidl, Rewe, Edeka, Hofer, Billa or in organic supermarkets such as Denn's Biomarkt or Alnatura . Leaves are occasionally available regionally in online shops or in subscription boxes. You can sometimes buy pre-grown plants in garden centers.

The availability of nasturtiums varies depending on the size of the store, catchment area, etc. You can find our recorded food prices for the DA-CH countries above under the ingredient image - and by clicking you can see their development at different suppliers.

Storage tips

Nasturtiums should be eaten as fresh as possible - the leaves and flowers do not store well. They only last 2-3 days in the fridge. ³³

If you don't want to go without nasturtiums outside of the season, you can dry them and use them as a tea or spice. Nasturtiums are best frozen for cooked dishes because the leaves and flowers are mushy after thawing. But frozen flowers in ice cube trays are definitely an eye-catcher.

Ingredients - Nutritional values - Calories

Nasturtium has 31 kcal/100g, of which 0.5 g are fat, 4.8 g carbohydrates and 2.7 g protein. ³⁰

Nasturtium ingredients are characterized by a high vitamin K content (125 µg/100g). 60 g of the fresh herb covers the daily requirement. However, there are plants that contain much more vitamin K; e.g. dandelion with 778 µg/100g or chard (830 µg/100g). ³⁰

With its vitamin C content, nasturtium (60 mg/100g) trumps lemon (53 mg/100g); however, it cannot keep up with sweet pepper (yellow) (184 mg/100g).

The methionine content of nasturtiums (0.48 g/100g; 51% of the daily requirement) is similar to that of sunflower seeds and is even higher than that of eggs (0.38 g/100g) or tofu (0.11 g/100g). Chia seeds (0.59 g/100g) and unpeeled hemp seeds have a higher methionine content. ³⁰

You can find all the ingredients of nasturtium, the coverage of the daily requirement and comparison values with other ingredients in our nutrient tables. In the article Nutrients explained you will get a detailed insight into the topic.

Health effects

Is it healthy to eat nasturtium? The plant is rich in micronutrients such as potassium, phosphorus, calcium, magnesium, zinc, copper and iron . Nasturtium has a variety of beneficial health effects: antioxidant, expectorant, hypotensive (lowering blood pressure), antibacterial and anticarcinogenic. ¹

Secondary plant substances

Many of the health effects of nasturtiums can be attributed to the secondary plant substances they contain. Our article on secondary plant substances provides an overview of the classification of substance groups, their occurrence in foods and possible effects on humans. Various parts of the nasturtium plant contain the following secondary plant substances, among others:

• Isoprenoids : Tetraterpenes: Carotenoids (α-carotene, β-carotene), xanthophylls (lutein, zeaxanthin, violaxanthin, zeinoxanthin, β-cryptoxanthin) ^{1,2,3,20,24,34}
• Polyphenols : Phenolic acids: hydroxycinnamic acids (caffeoylquinic acid); flavonoids: flavonols (isoquercitrin, quercetin-3-o-glycoside, kaempferol, myricetin), anthocyanidins (pelargonidin, delphinidin, cyanidin); tannins ^{1,4,7,8,9,10,11,20,24,31,34}
• Organic sulphur-containing compounds : Glucosinolates (Glucotropaeolin), Isothiocyanates ^{4,12,18,19,20,34}

However, it should be noted that the composition of the secondary plant substances in nasturtiums can vary depending on the variety, time of harvest and growing conditions. Therefore, quantities are only of limited use and should only be understood roughly.

The contents of secondary plant substances are not the same in leaves and flowers. Carotenoids and anthocyanins are present in greater quantities in flowers than in leaves. The total phenol content is similar in flowers and leaves. ^20.34

The carotenoids zeaxanthin and lutein found in nasturtiums lead to an improvement in eye diseases such as glaucoma (cataracts) and diseases of the retina (macular degeneration) when ingested through food. ² Xanthophylls, which include lutein and zeaxanthin, are pigments that protect the eye from oxidative stress. Lutein is also an important substance for the human brain and is involved in various cognitive processes, such as language and memory. ³

In combination with horseradish root ( Armoracia rusticana ), nasturtium is used for bronchitis, ^14,16 and inflammation of the paranasal sinuses (rhinosinusitis, sinusitis). ^13,16 Nasturtium also has a healing effect on urinary tract infections ¹⁶ and catheter-associated urinary tract infections ¹⁷ and increases the amount of urine (diuretic). ¹⁵ A combination with horseradish root is used to broaden the spectrum of effects, as nasturtium does not help against the Pseudomonas bacteria, which can cause infections of the urinary tract or upper respiratory tract. ¹⁶ This effect is based on isothiocyanates, formerly known as mustard oils. Isothiocyanates are formed from specific glucosinolates. Absorption takes place in the intestinal tract and excretion via urine, where the isothiocyanates exert their antimicrobial activity. ¹⁹ The horseradish root provides the allyl and phenylethyl isothiocyanate, the nasturtium provides the benzyl isothiocyanate. This combination therefore has the spectrum of action of a broad-spectrum antibiotic. ¹⁸ It should be remembered that there is variability in the glucosinolate content in the leaves. For medicinal applications, varieties with a high glucosinolate content should be chosen. ¹⁹

The flavonoids, phenols and tannin components contained in nasturtium play a role in its antioxidant effect. It also has an antibacterial effect on Staphylococcus aureus . ²⁴

The flowers of nasturtiums contain anthocyanins in quantities similar to those found in blackberries or strawberries . ³¹ Pelargonidin-3-sophoroside, delphinidin-3-dihexoside and cyanidin-3-sophoroside are the main anthocyanins. ⁴ Anthocyanins are pigments from the group of flavonoids. They are responsible for the red-orange and blue-violet colors ⁵ in the flowers of nasturtiums. ⁴ Anthocyanins have antioxidant, anti-inflammatory and anti-cancer properties and can help against certain heart diseases, as well as reduce the risk of developing diabetes or cognitive disorders. ⁶

It also contains the flavonoids quercetin and kaempferol glycosides. ^7,8,9,11 One study examined the hypolipidemic effect of nasturtium in rats. Researchers concluded that nasturtium has potential antihyperlipidemic activity. Active ingredients in nasturtium caused a significant reduction in all lipid parameters and increased good cholesterol. It also had a relaxing effect on the aorta, promoting the evacuation of excess cholesterol. The polyphenol content, especially isoquercitrin and caffeoylquinic acid derivatives, were the main bioactive compounds that triggered such activity. ⁷ Kaempferol, which belongs to the group of flavonoids, plays a role in several signaling pathways in the body. Kaempferol is said to have anti-inflammatory, anti-cancer and anti-diabetic effects. ¹¹

There is also evidence that isoquercitrin has a blood pressure lowering effect. Long-term treatment with an ethanol extract from nasturtium prevents an increase in blood pressure (renovascular hypertension) in rats and has a significant reno- and cardioprotective effect. ^8,10 If left untreated, high blood pressure can lead to various kidney and heart diseases. ¹⁰

One of the main active ingredients of the nasturtium plant is glucotropaeolin, with the highest content being found in the leaves. ⁴ When glucotropaeolin is broken down, benzyl isothiocyanate is formed. This substance has an antimicrobial effect. This means that nasturtium has great potential as a feed additive in animal husbandry. In one experiment, animal feed was enriched with nasturtium seeds (1 g cress seeds/kg feed). The isocyanate content was measured via the piglets' urine. This was sufficiently high to achieve the desired antimicrobial effect. ¹²

Dangers - Intolerances - Side effects

Can nasturtium be poisonous? Studies have not found any toxic effects. ²⁵ However, in the early stages of pregnancy, taking an extract from nasturtium can have a negative effect, as it makes implantation of the embryo more difficult. This is the conclusion reached by researchers in a preclinical study on rats. ²⁶

Are seed oils unhealthy? The seeds of nasturtiums contain high amounts of erucic acid. ¹ Above a certain amount, erucic acid can have a toxic effect on humans and damage the heart. The European Food Safety Authority ( EFSA ) therefore set a limit of 2% erucic acid in cooking oils in 2016. According to the EFSA, a daily intake of 7 mg/kg body weight is not harmful for adults. ²⁷

Erucic acid is also contained in a drug for a hereditary metabolic disease (adrenoleukodystrophy). ¹

Since mustard oil can irritate mucous membranes, people with stomach and intestinal ulcers or kidney disease should avoid nasturtiums. Excessive consumption is also not recommended. Infants and small children should also not eat the herb. ²⁰

Use as a recognized medicinal plant

There is a positive monograph by Commission E on nasturtium. ^20,21 The drug, 'Tropaeoli herba' is obtained from the nasturtium herb. The herb is used for urinary tract infections and catarrh of the respiratory tract. ²⁰

Folk medicine - natural medicine

In European folk medicine, nasturtium is used for menstrual disorders, to purify the blood, for fresh wounds, and in the past also as an antiscorbutic, cough remedy and for flatulence (meteorism). ²⁰ In Brazil, nasturtium is used for cardiovascular diseases, urinary tract infections, as a diuretic, for asthma and constipation, ²⁰ in South America the plant is used for infected wounds, ²² in Peru for hair loss and in Argentina for tuberculosis. ²⁰

Ecological footprint - animal welfare

We have not found any studies on the ecological footprint of nasturtiums, we only give a rough estimate here using comparable foods:

The CO ₂ footprint of herbs planted in pots in a greenhouse was the subject of research in Sweden and was 4.67 kg CO ₂ eq/kg. The scientists compared this value with various scenarios: The CO ₂ footprint could be reduced by several percent with measures such as biological fertilization instead of chemical synthetic fertilizers or reducing fossil fuels. Seasonal differences also influenced the actual footprint of the herbs. ³⁶

As a rule, herbs can be produced in a climate-friendly way. Various actors (including Greenpeace ) have calculated figures for various herbs in the All you can eat for climate collaboration: watercress came to 0.32 kg CO ₂ eq/kg, parsley to 0.26 and coriander to 0.41 kg CO ₂ eq/kg. These footprints correspond to a climate-friendly diet; even when they are put in relation to the nutritional value. ³⁷

Nasturtiums can also be grown wonderfully in your own garden or on the balcony, or you can buy them from a trusted gardener. Make sure you buy organic quality, because nasturtiums kept as ornamental plants can be heavily contaminated with pesticides. ³⁴ It is also possible to grow nasturtiums in the home in the form of 'microgreens'. ²²

We found no data on the water footprint of nasturtiums. Spinach has a global average water footprint of 292 l/kg andlettuce 273 l/kg. These values are below the average for vegetables (322 l/kg). ³⁹ The water footprint of nasturtiums is probably in this range. Experience has shown that they are somewhat more drought tolerant than most lettuces. In any case, one can generally assume that they have a good water balance.

Nasturtium is susceptible to pests, viruses and fungal infections. In organic vegetable gardens, it can therefore also be used as a trap crop or pest trap, especially for black aphids and cabbage white butterfly caterpillars. ³² It should be noted that there are biological methods to keep pests and pathogens of nasturtium in check. ³⁴

For detailed explanations of various sustainability indicators (such as ecological footprint, _CO2 footprint, water footprint), see our article: What does the ecological footprint mean?

Animal protection - species protection

In some regions, eg New Zealand and Hawaii, the fast-growing nasturtium suffocates the native, naturally occurring vegetation. This can have negative consequences for habitats and biodiversity of animals as well as plants. ³²

Various species of bees use the flower as a source of food. ³⁸

Worldwide occurrence - cultivation

Nasturtiums originate from South and Central America. ⁹ They are native to Peru, Bolivia and Ecuador. There they grow in mountainous regions, creeping and climbing in rock formations. ^22,23,35 They were brought from Peru to Europe in the 17th century. ²⁰ Today, nasturtiums are native to Europe, Asia, Africa, North America, Australasia and the Pacific region. ³²

Cultivation - Harvest

Nasturtiums are very sensitive to frost. Therefore, they should be grown early or sown directly from mid-May. To ensure that the plant produces plenty of flowers, it is advisable to fertilize only moderately - compost is ideal for this. The seeds are planted 2 cm deep and 10 cm apart; there should be a distance of 20 cm between rows. The plant thrives best in a sunny spot or in partial shade. ²⁸

In Central Europe, nasturtiums are annuals, and in warmer areas they are occasionally perennials. The herbaceous plant has a thin main root and forms underground runners. Round leaves of 3 to 5 cm in size grow on a succulent stem of up to 10 m in length ³² and are connected to the stem in the middle of the leaf spine. The flowers are orange to red (depending on the variety) and bloom from May to October. The fruit has a wrinkled surface and consists of three parts. The spongy fruit tissue is ideal for spreading through flowing water. ²⁰

From summer to autumn you can harvest leaves, flowers, buds and seeds. ³³

Further information

The large nasturtium ( Tropaeolum majus ) belongs to the order of cruciferous plants (Brassicales).

The leaves of the nasturtium are self-cleaning thanks to their special cuticle (wax layer on the leaves). This effect, the so-called 'lotus effect', can be observed impressively when it rains. As long as the wax layer on the leaves is intact, every drop of water simply rolls off. ²³

Alternative names

In German-speaking countries, nasturtiums are also called Kapuzinerli, Stigüferli, flower cress, yellow bird, Jelängerjelieber, salad flower, salad cress, Spanish nasturtium or Turkish cress.

In English, nasturtium is known as 'Indian cress', 'garden nasturtium' or 'nasturtium'. The name 'Nasturtium' is somewhat misleading, as it is also the genus name of watercress ( Nasturtium officinale ).

The drug name is 'Tropaeoli herba'.

Origin of the botanical name Tropaeolum majus : Since the leaf of the nasturtium resembles a shield and the flowers look like helmets, it was decided to name the plant genus Tropaeolum . 'Tropaeolum' is a diminutive form of 'tropaeum' - a Latin word that can be translated as 'victory monument'. The nasturtium, hung with the war paraphernalia of shield and helmet, was seen as a symbol of victory. ^20,29