Scurvygrass

What is Scurvygrass?

Scurvygrass is a small coastal plant in the cabbage family. Its proper name is Cochlearia officinalis. In Irish it is called biolar trá.

The fleshy leaves taste sharp and peppery, a bit like cress. Sailors and coastal people once ate them fresh in spring. They used them to stop scurvy, a disease caused by too little vitamin C.

That part of the story holds up. Fresh scurvygrass leaves do carry vitamin C, and vitamin C prevents and treats scurvy.

Everything else is weaker. No modern human trials of the plant itself appear in the medical literature. Long use in folk medicine is not proof that a remedy works, nor proof that it is safe.

How does Scurvygrass work?

The one solid mechanism is simple. The fresh leaves supply vitamin C, and vitamin C prevents and treats scurvy. Drying and long storage cut that vitamin C sharply.

The hot, mustardy taste comes from glucosinolates. When you chew or crush the leaf, these turn into mustard oils (isothiocyanates).

In test-tube studies, mustard oils from cabbage-family plants slow the growth of some bacteria. Whether they do anything useful inside the body is not established.

Folk writers also called scurvygrass a water pill (diuretic) and a "blood cleanser". Those ideas were never tested in people. Treat them as tradition, not as findings.

What forms does Scurvygrass come in?

You will mostly meet scurvygrass as a plant, not a product:

- Fresh leaves, foraged and eaten raw in salads. - Fresh juice pressed from the leaves, a very old preparation.

- Dried herb for tea, sold by a few specialist herb suppliers. - Tincture (an alcohol extract), rare and not standardised.

It is not a mainstream supplement. There is no agreed strength, no standard extract and little quality testing behind it.

Where it comes from:

Scurvygrass was one of the best known plants in northern European folk medicine. Writers from the 1500s onward named it as the cure for scurvy at sea and on land.

Ships carried it dried or as juice, though drying blunted its value. The naval surgeon John Woodall wrote about it in the early 1600s.

In England, "scurvygrass ale" was sold as a spring drink for hundreds of years. Folk use also covered sluggish digestion, sore gums and spring tiredness.

Citrus fruit and later tablets of vitamin C replaced it. Today the plant is better known for spreading along salted roadsides than for medicine.

What does Scurvygrass help with?

• Preventing scurvy (vitamin C deficiency): This is the only use with a clear basis. Scurvy comes from too little vitamin C, and fresh scurvygrass leaves contain vitamin C. Eating the fresh plant can help top up intake. The effect comes from the vitamin, not from anything unique to this herb. No trial has measured scurvygrass itself against a tablet or against fruit. If you think you have scurvy, see a doctor rather than treating it yourself.
• Sore or bleeding gums linked to low vitamin C: Bleeding gums are an early sign of scurvy, and tradition used scurvygrass for them. Where low vitamin C is the cause, raising intake helps. That is established for vitamin C in general, not for this plant on its own. Bleeding gums have many other causes, such as gum disease. Get them checked rather than assuming the cause.
• Spring tonic and poor appetite: Folk use treated the sharp leaves as a spring pick-me-up after a winter of stored food. In plain terms, the food supply was poor and the fresh greens helped. That is a reasonable guess, not a tested claim. There are no human studies of scurvygrass for tiredness or appetite.
• Sluggish digestion: Bitter, pungent leaves were widely used in Europe to "wake up" digestion. No trial has tested scurvygrass for bloating, slow digestion or any gut complaint. The claim rests on taste and custom. For some people the mustard oils do the opposite and cause heartburn.

Which foods are rich in Scurvygrass?

Scurvygrass is itself a food plant, eaten raw like cress. Vitamin C is the part that matters, and you can get it far more reliably from everyday foods. Citrus fruit, peppers, broccoli, strawberries and potatoes are all good sources.

What are the side effects of Scurvygrass?

• Burning or tingling in the mouth and throat
• Heartburn or stomach pain
• Nausea
• Loose stools
• Skin rash or itching in people allergic to cabbage-family plants
• A salty taste, since coastal plants take up salt

Good to know:

Eaten as a salad herb, scurvygrass is usually well tolerated. Most reported problems are mild and come from the mustard oils that give it its bite.

Strong juice, large amounts or concentrated extracts are more likely to irritate the mouth and stomach.

Serious harm has not been reported, but that partly reflects how little the plant has been studied. Absence of reports is not the same as proof of safety.

How much Scurvygrass should you take?

• Recommended daily: There is no agreed dose, because the plant has not been studied in people. Where dried herb is sold, labels often suggest about 1 to 2 grams for a cup of tea, roughly a heaped teaspoon. That is a label figure, not advice for you. As a food, people eat it the way they eat cress: a few fresh leaves in a salad. Strength varies with season and site, so the same amount of plant is not the same amount of vitamin C.
• Best time of day: Time of day does not matter. Vitamin C intake works the same morning or evening. Some people find the sharp mustard taste harsh first thing. If so, take it with a meal instead.
• With or without food: Food is fine and often better. The mustard oils can sting an empty stomach. Eating the fresh leaves as part of a salad is the oldest and gentlest way it was used.
• Time to effect: It depends on what you expect, and it may do nothing at all. Where scurvy is the problem, vitamin C works quickly. Gum bleeding and tiredness usually ease within days to a few weeks of proper treatment. For tiredness, appetite or digestion there is no evidence base at all. If nothing changes in two to three weeks, it is not working for you.
• How long to take it: No safe long-term period has been set, because no one has studied it over time. Traditional use was seasonal. People ate it for a few weeks in spring, when fresh greens were scarce. Daily use for months is outside anything tradition or research covers.