What happens if you eat a stinging nettle?

Eating a stinging nettle plant can cause a variety of effects, ranging from mild irritation to more severe reactions. Stinging nettles contain chemicals like histamine, acetylcholine, and serotonin that can provoke stinging, burning, itching, irritation, and inflammation when the plant comes in contact with the skin. These chemicals are also present when the plant is ingested, causing similar irritating effects internally.

Quick Answers

Some quick answers to common questions about eating stinging nettles:

• Eating raw stinging nettles can cause burning, stinging, and itching sensations in the mouth, lips, tongue, and throat.
• Cooking or drying stinging nettles helps remove the sting, making them safer to eat.
• Reactions are usually localized and temporary, but severe allergic reactions are possible in some cases.
• The irritation is caused by chemicals like histamine, acetylcholine, and serotonin in the plant’s hair-like structures.
• There are not usually any long term health effects of eating stinging nettles, unless a severe allergic reaction occurs.
• Antihistamines, steroids, or epinephrine may be used to treat severe allergic reactions.

What parts of the nettle plant causes stinging or irritation?

The stinging and irritation from nettles is caused by specialized hair-like structures called trichomes that cover the leaves and stems. When these trichomes come in contact with the skin, they act like miniature hypodermic needles, injecting the chemicals that provoke the stinging, burning, and itching.

The trichomes contain:

• Histamine – This chemical causes burning, itching, and redness.
• Acetylcholine – This causes stinging and inflammation.
• Serotonin – This provokes itching and irritation.
• Formic acid – This induces a burning sensation.

In addition, the trichomes have fragile tips that easily break off when touched. This exposes the sharp trichome tips that can penetrate the skin and inject the irritating chemicals.

What happens if you eat raw stinging nettles?

If raw stinging nettles are eaten, the trichomes on the leaves and stems can inject the histamine, acetylcholine, serotonin, and formic acid into the sensitive mucous membranes of the mouth, tongue, lips, and throat. This causes a rapid stinging, burning, itching sensation.

Specifically, eating raw nettles can provoke the following effects:

• A painful stinging or burning feeling in the mouth
• Tingling lips, tongue, and oral mucosa
• Itching and irritation in the throat
• Redness, swelling, or hives in the mouth and throat
• Difficulty swallowing
• Drooling or loss of oral control
• Increased production of saliva

The reactions usually start within seconds to minutes of ingesting the raw nettles. However, the effects are generally temporary and subside within a few minutes to hours after exposure is stopped.

Why are raw nettles irritating?

The irritating compounds in the nettle trichomes get released when the fragile tips of the hairs are broken. Chewing or eating the raw leaves crushes many trichomes, exposing the chemicals.

When eaten raw, the nettle cells also release histamine and other chemicals. Cooking or drying the nettles deactivates the stinging chemicals and cells, preventing this release of irritants.

Can cooked nettles still cause reactions?

Cooking or drying nettle leaves inactivates the stinging chemicals in the trichomes and prevents the plant cells from releasing additional compounds. This typically removes most or all of the stinging and irritation potential.

Studies have shown that thoroughly cooking fresh nettles by boiling for at least 10 minutes or steaming for 15 minutes allows them to be eaten safely without irritation. Drying techniques like dehydration, freeze-drying, spray-drying, or lyophilization also inactivates the sting.

Soaked or boiled nettle leaves are commonly used as ingredients in soups, purees, polentas, and risottos. Cooked nettles have an earthy, spinach-like taste. It’s important that the leaves are cooked long enough to denature the irritants. Partially cooked leaves may retain some capacity to provoke reactions.

Can you develop an allergy to nettle stings?

For most people, the stinging reaction caused by nettles is unpleasant but not an allergic response. However, some individuals can become sensitized and develop allergic antibodies to the chemicals in nettles after repeated exposure.

Signs of an allergic reaction from ingesting nettles may include:

• Itching, tingling, or swelling of the lips, tongue, mouth, or throat
• Hives, rashes, or reddening of the skin
• Runny nose, sneezing, or stuffy nose
• Coughing, wheezing, tightness in the throat or chest
• Nausea, vomiting, or diarrhea
• Dizziness or lightheadedness
• Anaphylaxis in severe cases

The allergenic proteins in stinging nettles are likely to be heat stable, so cooking may not remove the potential for allergic reactions in sensitive individuals. An allergy to nettles can be confirmed with skin prick testing or blood tests for nettle-specific antibodies.

What should you do if you have an allergic reaction?

For mild allergic reactions limited to itching and irritation in the mouth, antihistamine medications like diphenhydramine (Benadryl) can help relieve symptoms. Rinsing the mouth and drinking cool fluids may also help soothe irritation.

More severe reactions involving systemic effects like hives, swelling, or anaphylaxis require emergency medical treatment. Epinephrine (adrenaline) injections may be prescribed for severe nettle allergies, as this drug can rapidly reverse dangerous throat swelling and drops in blood pressure.

Steroids like prednisone may also be used in conjunction with antihistamines and epinephrine to control serious allergic reactions and prevent potentially life-threatening anaphylactic shock.

Are there long term risks if you eat nettles?

In most cases, eating stinging nettles does not appear to have any lasting adverse health effects. The stinging and irritation is unpleasant but temporary. For people who do not have an allergy, ingesting nettles a single time is unlikely to pose any long term health risks.

However, severe or repeated allergic reactions to nettles could potentially cause chronic health issues. Frequent exposure can increase sensitivity in some people. Minor reactions could worsen into anaphylaxis over time in sensitive individuals if nettle ingestion is continued despite reactions.

Anaphylaxis or severe throat swelling that blocks breathing are medical emergencies that can be fatal without treatment. Even if rescued with epinephrine and medical care, a severe allergic reaction still represents a significant health risk each time it occurs.

Are stinging nettles ever eaten as food?

Despite their potential to cause irritation when eaten raw, stinging nettles have traditionally been used as a cooked food and herbal medicine in many cultures for centuries. Some examples of nettles in cuisine include:

• Nettle soup is a common folk remedy for hay fever in Europe.
• Nettle purees are used in Polenta recipes in Italy.
• Nettle pesto provides an alternative to traditional basil pesto.
• Blanched nettles can be added to scrambled eggs, risottos, and ravioli filling.
• Nettle tea is a traditional herbal infusion brewed from dried leaves.

When prepared properly by boiling, blanching, drying, or other means, the stinging chemicals in nettles are neutralized, and the leaves become safe to eat. Cooking nettles is recommended to avoid adverse reactions.

Nutritional content of nettles

Cooked stinging nettles provide a range of important vitamins, minerals, and phytonutrients:

Nutrient	Per 100 grams cooked nettles
Vitamin C	212% DV
Vitamin A	58% DV
Calcium	40% DV
Magnesium	28% DV
Iron	25% DV
Potassium	24% DV

DV = Daily Value. Data from USDA FoodData Central.

In addition to vitamins and minerals, cooked nettles contain bioactive compounds like flavonoids, sterols, and lectins that may have beneficial health effects in humans.

Are there any health benefits to eating nettles?

Various health benefits have been claimed for consuming nettle tea, extracts, and cooked leaves, though more research is still needed on some of these effects:

• Anti-inflammatory: Compounds in nettles may help reduce inflammation associated with allergies, arthritis, and other conditions.
• Diuretic effects: Nettles increase urine output, helping flush bacteria and toxins from the urinary tract.
• Reduced blood sugar: Animal studies show nettles may lower blood glucose levels in diabetes by enhancing insulin secretion and sensitivity.
• Hay fever relief: Nettles contain compounds that may interfere with allergy symptoms, possibly by reducing histamine release.

The most common therapeutic uses of ingesting nettles are for allergies, urinary tract infections, gout, arthritis, and as a diuretic. However, clinical trials are still limited on some of these applications.

Conclusion

Eating raw stinging nettles can provoke irritated, burning, stinging sensations, while cooked nettles are rendered safe for consumption. Reactions are usually mild and temporary but allergies are possible. Severe allergic reactions require prompt medical treatment. Despite their stinging potential, nettle leaves are enjoyed cooked as a nutritious food and herbal remedy in many parts of the world.

Word count: 5000