History and Origin
Many people consider nettle (Utica) as an annoying plant, although, this plant has been used for food, clothing, and medicine since ancient time. The scientific name of nettle is derived from the Latin word meaning” burn”, which refers to the pungency (bite) trait of the leaves of the plant. Its English name is derived from Anglo-Saxon language and from the word of “Noedle or needle”. Due to the contact of the body with the biting hairs of this plant, the caustic contents of these hairs which are formic acid enter the skin and cause burning. Nettle is growing in most wet areas of the country, especially in the north, west and central Iran.
Nettle Health Benefits
1. Increasing Antioxidant Activity
Phenolic ingredients in nettle can chelate the metal ions (bands with them) and thus reduce their concentration in lipids peroxidation. Neutralization of H2O2 by water extract of nettle can be attributed to its phenolic ingredients which can give electrons into H2O2 and change it to water and neutralize them.
2. Diuretic
A research that its results were published in Iraqi Journal of Veterinary Sciences showed the diuretic property of liquid extract nettle in rabbits. The use of nettle extract in these animals increased volume of urine and repels sodium ion. This effect of nettle is similar to Furosemide drug. Researchers believe that the diuretic property of nettle can be related to its deterrent effect on the Adenosine receptor.
3. Improving Kidney Function
Based on a research in Koomesh Journal, the extract of nettle reduced poisonous (toxic) effects caused by Gentamicin on rats. Gentamicin is from Aminoglycoside antibiotics that is used to cure some infections caused by Gram-negative bacteria and due to having side effects as renal toxicity its usage is limited. This research has shown that nettle extract probably can affect the improvement of Gentamicin toxic effects on kidney by decreasing oxidative stress and creating anti-inflammatory effects and vasodilation. Nettle extract contains lycopene that acts as an anti-oxidant and prevents necrosis of the cells by trapping free radicals (death of cells due to injury).Based on a research in Koomesh Journal, the extract of nettle reduced poisonous (toxic) effects caused by Gentamicin on rats. Gentamicin is from Aminoglycoside antibiotics that is used to cure some infections caused by Gram-negative bacteria and due to having side effects as renal toxicity its usage is limited. This research has shown that nettle extract probably can affect the improvement of Gentamicin toxic effects on kidney by decreasing oxidative stress and creating anti-inflammatory effects and vasodilation. Nettle extract contains lycopene that acts as a powerful anti-oxidant and prevents necrosis of the cells by trapping free radicals (death of cells due to injury).
4. Improving Thyroid Gland Function
Steroids ingredients that are also in nettle reduce transferring proteins of thyroid hormones in blood serum. This reduction by itself reduces the amount of T3 hormones (Triiodothyronine and T4 thyroxine or tetrayodotironina). Flavonoids reduce the amount of these hormones by inhibiting the activity of the throperoxydase enzyme (the responsible of biosynthesis of thyroid hormone). Flavonoids by inhibiting the activity of Diodenase enzyme (a kind of enzyme that separates iodine from these hormones and for resynthesis of hormone, provides it for thyroid gland) and prevention of iodine mineralization in thyroid cells change the amount of thyroid hormones.
5. Improving Cardiovascular System Function
The results of considering ethanol extract effect of nettle foe arrhythmia treatment (heart beat abnormally) of ultra-ventricular in rabbits’ heart showed the potential role of anti-arrhythmia of hydroalcholic extract of this plant. The findings indicate that the nettle probably with inhibition of sodium-potassium pump depend on energy applies its effect.
Based on studies done on laboratory animals, nettle extracts improve lipid profiles and prevent platelet aggregation. The platelets play a role in blood clotting and coagulopathy bleeding disorder can cause the myocardial infraction (heart attack). Liquid extract of nettle leaf that was given to rats prevented platelet aggregation caused by Thrombin (factor IIa, a serine protease that converts fibrinogen into fibrin in blood coagulation). It seems that the flavonoids are responsible for this inhabitation power.
6. Improving Liver Function
The nettle has a protecting effect on liver. This plant is a powerful anti-oxidant that breaks free radicals and reduces oxidative stress. Nettle increases Arylstrasse, Paraoxonase and liver tissue Catalase activity in liver tissue and can prevent fibrosis (leaf tissue swelling) and alcoholic liver (intense inflammation of liver). Nettle does this act with antioxidant activities and regulating immune system.
7. Improving Digestive System Function
Nettle plant causes protecting of small intestinal mucosa. According to researchers this matter can be due to improving nervous system with mechanisms of reducing production of Sorbitol. This plant prevents increasing glucose inside the cell and improves blood supply tissue repair through appropriate decreasing of blood glucose. Nettle debarment glucose aggregation and as a result by Sorbitol in nervous cells that causes injury the cells and prevents access of neuropathy (disorder in nerves) as the function of the neural cells on the intestinal tract is improved and their atrophy (burn out) is improved. Also with improving blood supply it plays a role in intestinal mucosa repair and can prevent pathogen entrance with mucus conjunction repair and as a result reduces inflammation factors activity complications caused by it such as destruction, bleeding and necrosis.
8. Regulating Blood Glucose Levels
In an experiment, it was shown that the use of nettle aqueous extract to 250mg/kg of body weight, 30 min before glucose loading, had a strong glucose lowering effect. In contrast, nettle did not show hypoglycemic effect in alloxan-induced diabetic rats.
In the other research, amount of serum glucose and resistance to insulin in male rats reduced after the use of hydroalcoholic extract of nettle leaf.
Also consumption of nettle leaf extract in diabetic rats increased insulin secretion of pancreas and finally reduced blood glucose.
The researchers in other research that its results were published in PharamAnal acta Journal in 2017 were reported that orally use of nettle aqueous extract reduces plasma glucose in diabetic Syrian mice. In some sources it has reported that the cause of reducing blood glucose followed by nettle consumption is the effect of this plant on pancreas Beta cells, increasing allergy to insulin or insulin-like activity of this plant.
The researchers know the increasing insulin secretion from islets of Langerhans Beta cells and/or releasing insulin from its resources are responsible for diabetes control. Some researchers know this act mechanism is decreasing Albumin glycosylation and fructosamine and some people mentioned nettle effect on inhibition intestinal Alpha-glucosidase causes reducing blood glucose.
Other recommended mechanisms include increasing peripheral consumption of glucose, increasing synthesis of liver glycogen, inhibition of glucose intestinal absorption, decreasing glycemic index of carbohydrates and decreasing glutathione effect phytochemicals. Studies of nettle indicate the presence of tanins, saponins, flavonoids, alkaloids and phenol in this plant. Quercetin flavonoids and ferulic acid affect pancreatic β-cells and improve this cells proliferation and as a result increase insulin secretion in diabetic rats.
9. Regulating Blood Cholesterol Levels
The results of an experiment that was done on patients with type 2 diabetes the positive effect of nettle extract showed on lipidic condition and blood pressure. In this experiment nettle extract reduced triglyceride level and systolic blood pressure and increased useful cholesterol (HDL). Researchers believe that these effects of nettle can be due to existence of flavonoids in this plant. According to researchers, it is possible that one of probable mechanisms caused by nettle usage can be increasing lipoprotein lipase activity that decreases triglyceride.
On the other hand Saponin and Tannin contents in nettle can reduce intestinal absorption of lipid and with inhibition cholesterol Esterase increase ratio HDL to LDL.
10. Regulating Blood Pressure
Laboratory researches show that nettle has the property of blood pressure decreasing. Nettle causes vasodilation and as reducing blood pressure that it does this effect with having Nitric oxide. A research on rats indicated that nettle reduces blood pressure in patients with type 2 diabetes. Primary blood pressure communicate resistance to insulin and increasing insulin secretion and increasing sensitivity to insulin with effect on acetylcholine causes vessels expansion and decreasing blood pressure. It seems the flavonoids in nettle are responsible for these effects.
11. Increasing Fertility
In Iranian Journal of Reproduction Medicine published the results of an experiment that investigates nettle effect on prevention of injuries to sperm and cause of nicotine consumption in Syrian mice. According to these results, hydroalcoholic extract of nettle causes increasing sperm quality and inhibition of injuries caused by nicotine on sperm traits (their number and movement). Increasing of sperm cells movement caused by the use of nettle can be due to inhibition from activity of Cannabinoids (the ingredients that activate some nervous system receptors). These materials with activate CB1 receptor in mature sperm cells, reduce sperm cells motility.
12. Anti-Inflammatory
Nettle extract can be effective on reduction of acute and chronic inflammation. In a research the extract of this plant was effective in reduction of rats’ ear inflammation. Nettle could reduce inflammation caused by Formaldehyde injections to the sole of the foot of animals. Probably Flavonoids of nettle extract can reduce amount of inflammation by inhibition of peripheral inflammatory mediators releasing. Inhibition of cytokines that are one of the most important inflammatory mediators has reported by nettle extract.
13. Anti-Allergy
Based on a research in Phytotherapy Research Journal, nettle extract can inhibit key inflammatory events that causes seasonal allergy. This plant has inhibitory effects on Histamine-1 (H1) receptor. Nettle extract prevents formation of Prostaglandins by inhibiting enzymes of the inflammatory pathway including Cyclooxygenase-1 (COX-1), Cyclooxygenase-2 (COX-2).
14. Improving Urinary Tract Function
Experiments have shown positive effects of nettle root in reducing urinary tract diseases associated with BPH (benign prostate enlargement) and reducing the size of prostate.
What Are Nettle Side Effects?
1. When taken by mouth: Generally, no health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages.
* Possible allergic reactions (skin afflictions, edema) have been observed in rare cases following intake of the herb.
2. Pregnancy and breast-feeding: Stinging nettle is LIKELY UNSAFE to take during pregnancy. It might stimulate uterine contractions and cause a miscarriage. It’s also best to avoid stinging nettle if you are breast-feeding.
3. Diabetes: There is some evidence stinging nettle above ground parts can decrease blood sugar levels. It might increase the chance of low blood sugar in people being treated for diabetes. Monitor your blood sugar carefully if you have diabetes and use stinging nettle.
4. Low blood pressure: Stinging nettle above ground parts might lower blood pressure. In theory, stinging nettle might increase the risk of blood pressure dropping too low in people prone to low blood pressure. If you have low blood pressure, discuss stinging nettle with your healthcare provider before starting it.
5. Kidney problems: The above ground parts of stinging nettle seem to increase urine flow. If you have kidney problems, discuss stinging nettle with your healthcare provider before starting it.
Generally, every person may be allergic to certain herbs and spices. This sensitivity must be first diagnosed by the person and secondarily by the physician. However, these allergic reactions do not cause chronic or acute side effects, and after identifying the allergenic plant and removing it from the diet, allergy-related complications will be eliminated. No company or product can be aware of the allergic reactions of different bodies in advance. The body's incompatibility with one or more specific herbs rarely occurs, but consumers may encounter it anyway.
Nettle Daily Dosage
The average daily dose is 8 to 12 g of herb.
To prepare an infusion, use 1.5 g finely cut herb in cold water, briefly bring to a boil and steep for 10 minutes, then strain.
Bioactive Compounds
Nettle contains phenolic compounds, tannins and sterols. Some components of this plant include acetylcholine, histamine, serotonin, carvacrol, carvone, naphthalene, geranyl acetone, coumarin, formic acid, acetic acid, lectin, caffeic acid, palmitic acid, linoleic acid and ferulic acid.
Best Time to Consume
1-2 hours before or after meals.
Possible Drug Interactions
1. Lithium: Stinging nettle might have an effect like a water pill or "diuretic." Taking stinging nettle might decrease how well the body gets rid of lithium. This could increase how much lithium is in the body and result in serious side effects. Talk with your healthcare provider before using this product if you are taking lithium. Your lithium dose might need to be changed.
2. Antidiabetes drugs: Stinging nettle above ground parts might decrease blood sugar. Diabetes medications are also used to lower blood sugar. Taking stinging nettle along with diabetes medications might cause your blood sugar to go too low. Some medications used for diabetes include glimepiride (Amaryl), glyburide, insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol) and tolbutamide (Orinase).
3. Medications for high blood pressure (Antihypertensive drugs): Stinging nettle above ground parts seem to decrease blood pressure. Taking stinging nettle along with medications for high blood pressure might cause your blood pressure to go too low. Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDiuril), furosemide (Lasix), and many others.
4. Sedative medications (CNS depressants): Large amounts of stinging nettle above ground parts might cause sleepiness and drowsiness. Taking stinging nettle along with sedative medications might cause too much sleepiness. Some sedative medications include clonazepam (Klonopin), lorazepam (Ativan), phenobarbital (Donnatal) and zolpidem (Ambien).
5. Warfarin (Coumadin): Stinging nettle above ground parts contain large amounts of vitamin K. Vitamin K is used by the body to help blood clot. Warfarin (Coumadin) is used to slow blood clotting. By helping the blood clot, stinging nettle might decrease the effectiveness of warfarin (Coumadin). The dose of your warfarin (Coumadin) might need to be changed.
6. Diclofenac: Studies have demonstrated that leaf extracts of Stinging Nettle when used along with diclofenac, enhance the anti-inflammatory effect of diclofenac.
Traditional Use
In traditional medicine nettle was used as anti-spasm, sputter, diuretic, and it was used to treat asthma and indigestion.
Some Questions about Nettle
Does stinging nettle lower blood sugar? / Does nettle tea help diabetes?
Several animal studies have shown that nettle has positive effects on diabetics, including:
- lowering blood glucose levels
- lowering resistance to insulin
- increasing pancreatic insulin secretion
- boosting Insulin sensitivity
For more information, see the “Nettle Health Benefits” section.
Why are stinging nettle so painful?
Contact urticaria frequently occurs when skin is exposed to the plant. Sharp hairs on the leaves and stems of nettle contain irritating chemicals that are released when the plant comes into contact with the skin. The urticaria is accompanied by a stinging sensation that can last for up to 12 hours after exposure.
Can stinging nettle lower PSA? / Is nettle tea good for prostate cancer or benign prostatic hyperplasia (BPH)?
Stinging nettle has a variety of health benefits, many of which involve supporting the health of the prostate. Stinging nettle help maintain normal urinary function while also encouraging the reduction of prostate size. Stinging nettle provides this support by inhibiting the conversion of testosterone into dihydrotestosterone, an androgen hormone that promotes benign prostate hyperplasia and other male issues associated with aging.
According to a 2005 study on 620 patients, nettle does not affect serum Prostatic-Specific Antigen (PSA) levels.
Does nettle leaf lower testosterone?
Stinging nettle inhibits the conversion of testosterone into dihydrotestosterone. As a result, it may help increase testosterone levels in the body.
Does nettle make your hair grow? / Can you leave nettle tea rinse in your hair?
In folk medicine, the plant is used externally as a hair and scalp remedy against oily hair and dandruff.
Who should not drink stinging nettle tea?
Generally, no health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages.
Before taking stinging nettle tea, consult your doctor if you have any of the following conditions:
Pregnant or nursing women, as well as those suffering from low blood pressure, kidney disease, or diabetes.
Can you be allergic to eating nettle?
A study found that nettle extract can inhibit key inflammatory events that cause seasonal allergies. This plant has inhibitory effects on the Histamine-1 (H1) receptor. Nettle extract prevents the formation of Prostaglandins by inhibiting enzymes of the inflammatory pathway including Cyclooxygenase-1 (COX-1), and Cyclooxygenase-2 (COX-2).
Note: Generally, every person may be allergic to certain herbs and spices. In rare cases, allergic reactions (skin afflictions, edema) have been observed following herb consumption.
Can nettle tea hurt kidneys?
A study found that nettle extract reduced the toxic effects of antibiotics on the kidney by lowering oxidative stress and creating anti-inflammatory effects and vasodilation. Nettle extract contains lycopene that acts as a powerful antioxidant and prevents necrosis of the cells by trapping free radicals (death of cells due to injury).
It should be noted that the above-ground parts of the herb seem to increase urine flow. If you have kidney problems, consult your healthcare provider before taking it.
