What You Will Learn in This Article
- What is Quercetin?
- What are Nettles?
- How Quercetin and Nettles Support Hormone Balance
- Antihistamine effect of Quercetin and Nettles
- Anti-inflammatory benefits of Quercetin and Nettles
- What I Recommend
- Nettle Tea Recipe
It surprises many women that allergies and hormones are intimately connected. Do you suffer from allergies, with congestion, scratchy throat, or itchy eyes? Do you also happen to have symptoms of estrogen dominance? These often go hand-in-hand. Excess estrogen can be highly inflammatory and drive up your histamine intolerance.
Quercetin and nettles can help. The great thing about these two immune-supporting ingredients is that they are also highly supportive of your hormones. By lowering inflammation, balancing blood sugar, supplying vitamin C, and addressing estrogen dominance, quercetin ad nettles are a powerful duo that you’ll want to have in your arsenal.
What is Quercetin?
Quercetin is a bioflavonoid found in fruits, vegetables, nuts, seeds, red wine, etc. Foods that are a good source of quercetin include capers, onions, cooked asparagus, cherries, tomatoes, red apples, berries, green or black tea, and more. Capers are the best source, while tea is on the lower end. (1)
However, the way the food is grown seems to make a difference in how much quercetin it provides. Tomatoes that were organically grown were 79% higher in quercetin than conventionally grown ones. (2) So, buy organic whenever possible to get the most quercetin and other nutrients out of your tomatoes.
Because quercetin is poorly absorbed, in supplements it’s often combined with other compounds, like enzymes, herbs high in vitamin C, or other bioflavonoids. (3, 4) In that way, the supplements are made to mimic the original food source of quercetin. For example, tomatoes, which contain quercetin, are also naturally rich in enzymes and vitamin C. So, keep in mind when looking for a supplement that you don’t want quercetin all by itself.
What are Nettles?
Nettles (Urtica dioica L.), also referred to as “stinging nettles” are leaves or stems (sometimes roots) from a bush that grows in forests, along roads, or by rivers or streams in the Northern Hemisphere. It’s referred to as “stinging” because the fine hairs that grow on the stems and leaves cause inflammation to the skin that feels like burning. A temporary rash may follow. (5)
Blending raw nettles or cooking deactivates these “stinging” compounds and allows us to eat them and benefit from their nutrients and therapeutic effects.
Nettles have long been used in folk medicine – in the United States and Canada as well as Europe. Whenever a food or herb holds a prominent role in folk medicine, you can expect clinical trials to follow. Often, the studies prove the efficacy of the herb for treating the very ailment the local healers used it for.
How did the local healers know to use that herb? Did they have some amazing intuition? Did they talk to the plants and ask which one could help?
In Eastern European countries, nettles were used to reduce arthritic pain — they would actually beat the patient with a bunch of nettles. It likely helped due to nettles’ anti-inflammatory properties (but probably didn’t feel good during the beating!)
How Quercetin and Nettles Lower Allergy Response
Women tend to have more histamine-related issues than men do. That’s because estrogen stimulates the release of histamine from the mast cells. When you’re estrogen dominant, you’re more likely to have high histamine levels. Additionally, as your histamine levels go up, your estrogen levels also rise. So, it’s a vicious cycle. (6, 7)
That’s where quercetin and nettles come in. Getting your histamine levels under control can go a long way toward balancing out estrogen levels and getting you out of Estrogen Dominance.
Quercetin may help with allergies. In a study published in Iran Journal of Allergy, Asthma, and Immunology, Italian researchers found that quercetin was as effective as an herbal Chinese formula, Food Allergy Herbal Formula (FAHF) in blocking anaphylaxis to peanuts in animal studies. They saw it as a potential allergy “drug.” (8)
Nettles also seem to help histamine and allergies, despite containing histamine themselves. In a cell study, several compounds in nettle extract were shown to work against seasonal allergies (hay fever) by fighting inflammation. (9)
In a human study in which patients were given freeze-dried nettles for allergies, 57% said nettle was ‘effective’ and 48% said the nettle worked better than their allergy medications had. (10)
However, unlike many over-the-counter choices to regulate histamine levels, the phytoconstituents of this plant extract do not cross the blood-brain-barrier. For that reason, it is unlikely to cause the drowsiness or other adverse events associated with common antihistamine OTC medications.
That means you don’t have to worry about getting drowsy after taking this antihistamine supplement. Nettles can be taken at any time of day.
How Quercetin and Nettles Lower Inflammation
Because quercetin and nettles lower inflammation and reduce oxidative stress, taking this combo can help with hormone balance. Inflammation can cause stress on the liver and make it harder to detoxify metabolized estrogen. That can contribute to Estrogen Dominance.
Another way lowering inflammation can help with hormone balance is by lowering aromatase activity. (11) Aromatase is an enzyme that helps the body create more estrogen. If that enzyme gets overactivated from too much inflammation, estrogen levels could get out of control, and lead to a situation of Estrogen Dominance.
The fact that this duo is anti-inflammatory means it can also help with things like joint pain, osteoporosis, psoriasis, hot flashes, and PMS. It also makes hormone receptors more sensitive, which means there’s better communication within your endocrine system. That means everything is more likely to work in harmony.
Plus, Quercetin has been found to work as a COX-2 inhibitor. (13) Drug versions of COX-2 inhibitors include NSAIDS like aspirin and ibuprofen. Other natural COX-2 inhibitors you might be familiar with include things like green tea and curcumin. (14) All these substances are common “go-to’s” for inflammatory conditions and general wellbeing. Again, we know that lowering inflammation is helpful for making hormone receptors more sensitive.
Some of the anti-inflammatory compounds in nettles include kaempferol, quinic acid, and choline. The flavonol kaempferol has been described as a potent anti-inflammatory. (15) Quinic acid is effective in treating atherosclerosis due to its ability to lower inflammation in the blood vessels. (16)
In the Nurses’ Health Study, those whose diets were richest in choline (associated with a Mediterranean Diet) had better blood levels of inflammation markers, including C-Reactive Protein. Again, nettles are a good source of plant-based choline. (17)
Nettles’ anti-inflammatory ability is also reflected in the herb’s effectiveness for pain relief. In a 27-person study of arthritis, a stinging nettle cream was very effective for pain compared to a placebo. (18) In a randomized double-blind study of 81 patients with osteoarthritis, a supplement containing nettles improved symptoms and decreased their need for NSAIDs and other pain meds. (19)
More Key Benefits of Quercetin
Quercetin has specifically been studied for a condition called idiopathic pulmonary fibrosis (IPF). “Idiopathic” refers to an unknown cause. According to the National Institutes of Health, symptoms of this condition include shortness of breath and dry cough. Symptoms may be different between people and may develop slowly or quickly. (25)
When IPF develops into an acute situation, this condition can lead to severe oxygen deprivation which requires a ventilator.
According to a 2018 study published in Critical Care, Acute exacerbation of IPF, referred to as AE-IPF, “shares several pathophysiological features with acute respiratory distress syndrome (ARDS), a very severe condition commonly treated in this setting.” You probably already know that ARDS is often the cause of death in people who die of the novel virus. (26)
The researchers mention that the known increased risk of ARDS death due to ventilator-induced lung injury has been a helpful lesson in advising care for IPF patients. This has been reflected with the novel virus, as 80% of people who have been put on ventilators for the novel coronavirus in New York have died. (27)
According to studies, IPF patients have been found to have significantly lower antioxidant levels in their bodies, including the master antioxidant, glutathione. They also have increased lung inflammation. (28)
According to that same study, published in 2017, quercetin is able to increase internally-produced antioxidants and decrease inflammation in the blood of patients with Idiopathic Pulmonary Fibrosis, which is very similar to ARDS.
Not only is quercetin anti-inflammatory, it’s specifically been shown to work as an antioxidant. Quercetin has shown antioxidant capabilities in cell studies as it reduces oxidative stress and increases Nrf2, a protein that helps protect cells and tissues from damaging free radicals. (29, 30)
A paper published in 2019 found a “Role of Nrf2 and its activators in respiratory diseases.” Nrf2 is important for airway health, and when it is low, patients are more likely to develop things like respiratory infections, asthma, COPD, lung cancer, idiopathic pulmonary fibrosis (IPF), and acute respiratory distress syndrome (ARDS). (31)
Antiviral and Immune Defense
Quercetin is even helpful in fighting viruses. In a Chinese cell study published in the journal Viruses in 2016, Quercetin was found to be preventative against the Influenza A virus. Specifically, quercetin was shown to prevent the virus from entering the cell. (32)
Quercetin is generally supportive of the immune system. It’s been shown in studies to stimulate the immune system, fight viruses, inhibit release of histamine, decrease inflammation, and improve the Th1/Th2 balance, so that the immune system is neither underactive or overactive. For that reason, it’s been proven helpful for asthma, allergies, and anaphylactic reactions. (33)
Researchers in Montreal are excited about quercetin as a possible remedy for the novel virus. Since it’s already proven to be effective against Zika virus and Ebola, there’s a good possibility quercetin could also help people fighting the novel coronavirus. Because it inhibits viral entry into cells, quercetin may prove to be a great preventative and treatment strategy. Clinical trials are underway in China as of early 2020. (34)
Healing Leaky Gut
Some studies indicate that quercetin could be helpful in healing a compromised gut lining, commonly referred to as “leaky gut.” It does this by improving the production of tight junction proteins which help connect intestinal cells and maintain the intestinal barrier. (23) Quercetin has been shown in animal studies to be able to heal injuries in the intestinal lining. (24)
Because increased permeability of the gut lining is associated with inflammation and autoimmune disease, using quercetin might be helpful in addressing autoimmune conditions such as Hashimoto’s, Rheumatoid Arthritis, or Inflammatory Bowel Disease.
It’s also important to address leaky gut if you want to restore balanced immune function.
More Benefits of Nettles
Vitamin C Content
Nettles are rich in the antioxidant vitamin C. Vitamin C has been shown to reduce inflammation levels in the body. In a study of 64 obese patients who had diabetes and/or high blood pressure, the treatment group recieved 500 mg of vitamin C twice a day for 8 weeks. (20)
By the end of the study, those who had taken the vitamin C had significantly lower inflammatory markers, including fasting blood glucose and C-reactive protein compared to the control group.
Additionally, because taking vitamin C has been shown to raise progesterone levels, it can help to address the estrogen-progesterone imbalance that occurs with Estrogen Dominance. (21)
Blood Sugar Balancing
Nettles may be helpful for balancing your blood sugar levels. You want to have balanced blood sugar levels if you want to balance your hormones. If your blood sugar fluctuates too much and goes too high and then too low, it will trigger your body to release adrenaline and cortisol.
In a study of 92 patients with advanced type 2 diabetes, nettle leaf extract was given to 46 patients (one 500 mg capsule every 8 hours for 3 months) combined with the conventional oral blood sugar drugs. The placebo group did not receive the nettles. At the end of the study, the nettle group had significantly lower fasting glucose levels, 2 hour postprandial glucose (following a meal), and HbA1c levels. (22)
The researchers concluded that nettle might be a safe way to control blood sugar in type 2 diabetic patients who need insulin therapy.
The release of those stress hormones leads to increased inflammation, increased estrogen, and a whole vicious cycle of hormone imbalance.
What I Recommend
Here at Wellena, we have sourced a high quality supplement that is a synergistic combination of quercetin and stinging nettle leaf in a 1:1 ratio. The high vitamin C content of the nettle extract helps the body absorb the quercetin, and they work together to bring down inflammation and support the immune system, among other benefits, listed above. You can try our Quercetin Plus Nettles supplements to help calm allergies and balance hormones here.
How We Extract Constituents in Our Supplements
Many supplements use chemical solvents to extract constituents like quercetin from their whole food sources. We use CO2 extraction, which ensures that the final product is pure and safe with no chemical residues left in the final product.
Herbal supplements like stinging nettles are standardized to ensure you’re getting a certain number of milligrams of the desired constituents. It’s a method of quality control that ensures a predetermined amount of a constituent is in the final product, regardless of the type of extraction used. That means that whether the extract is water soluble, alcohol soluble, et cetera, the supplement contains, say, 600 mg of extract, regardless of the amount of dry leaf used in making the product.
How to incorporate into your daily regimen
How to take: As a dietary supplement, take three capsules per day with meals, or as directed by your health care practitioner.
How to Make a Nettle Infusion
Don’t be fooled by the simplicity of this nettle infusion recipe. Nettles are deeply restorative for many of our body systems, providing a variety of phytonutrients, vitamins, and minerals.
Nettles are an excellent herbal remedy for allergies and histamine intolerance. Here are some more of their key medicinal properties:
- Very safe, slightly diuretic
- Highly nutritive; calcium, iron, magnesium, potassium and silica
- High in chlorophyll and vitamin C
- Gentle kidney tonic
- Uterine tonic
- Anti-inflammatory: Joint pain, Osteoporosis, Psoriasis, Hot flashes, PMS
All you’ll need is a bit of dried nettle leaves and filtered water. Click the link here for the full recipe.
Note: don’t use hot water with nettles; it reduces the vitamin C content.
Where to find more healing herbal recipes:
If you would like to explore how to use the healing power of herbs to build immunity, soothe allergies and balance hormones, I recommend my book, Overcoming Estrogen Dominance. You’ll find helpful food and herbal protocols along with healing recipes (from savory dishes to low sugar desserts) to help you on your health journey.
(1) Bhagwat, S. et al. USDA Database for the Flavonoid Content of Selected Foods Release 3.1. Agricultural Research Service, United States Department of Agriculture. May 2014.
(2) Mitchell, A. E. et al. Ten-year comparison of the influence of organic and conventional crop management practices on the content of flavonoids in tomatoes. Journal of Agricultural and Food Chemistry. July 2007.
(3) Graefe, E U et al. “Pharmacokinetics and bioavailability of quercetin glycosides in humans.” Journal of clinical pharmacology. 2001.
(4) Askari, G. et al. The effect of quercetin supplementation on selected markers of inflammation and oxidative stress. Journal of Research in Medical Sciences. July 2012.
(5) Kregiel, D. et al. Urtica spp.: Ordinary Plants with Extraordinary Properties. Molecules. July 9, 2018.
(6) Bonds, R. S., & Midoro-Horiuti, T. Estrogen effects in allergy and asthma. Current Opinion in Allergy and Clinical Immunology. 2013.
(7) Zierau, O., Zenclussen, A. C., & Jensen, F. Role of sex hormones, estradiol and Progesterone, in mast cell behavior. Frontiers in Immunology. 2012.
(8) Chirumbolo, S. Quercetin as a potential anti-allergic drug: which perspectives? Iranian Journal of Allergy, Asthma, and Immunology. June 2011.
(9) Roschek, B. et al. Nettle extract (Urtica dioica) affects key receptors and enzymes associated with allergic rhinitis. Phytotherapy Research. July 2009.
(10) Mittman, P. Randomized, double-blind study of freeze-dried Urtica dioica in the treatment of allergic rhinitis. Planta medica. February 2009.
(11) Morris, Patrick G et al. “Inflammation and increased aromatase expression occur in the breast tissue of obese women with breast cancer.” Cancer prevention research. 2011.
(12) Patel, Seema. “Disruption of aromatase homeostasis as the cause of a multiplicity of ailments: A comprehensive review.” The Journal of steroid biochemistry and molecular biology vol. 168 (2017): 19-25. doi:10.1016/j.jsbmb.2017.01.009
(13) Ramyaa, P. et al. Quercetin modulates OTA-induced oxidative stress and redox signalling in HepG2 cells — up regulation of Nrf2 expression and down regulation of NF-κB and COX-2. Biochimica et Biophysica Acta (BBA) – General Subjects. January 2014.
(14) Sagar, S. M. Natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer—Part 2. Current Oncology. June 2006.
(15) Otles, S. et al. Phenolic compounds analysis of root, stalk, and leaves of nettle. Scientific World Journal. April 19, 2012.
(16) Jang, S. A. Quinic acid inhibits vascular inflammation in TNF-α-stimulated vascular smooth muscle cells. Biomedicine & Pharmacotherapy. December 2017.
(17) Fargnoli, J. L. Adherence to healthy eating patterns is associated with increased circulating total and high molecular weight adiponectin and decreased resistin concentrations in women from the Nurses’ Health Study. American Journal of Clinical Nutrition. November 2008.
(18) Randall, C. et al. Randomized controlled trial of nettle sting for treatment of base-of-thumb pain. Journal of the Royal Society of Medicine. June 2000.
(19) Jacquet, A., et al. Phytalgic®, a food supplement, vs placebo in patients with osteoarthritis of the knee or hip: a randomised double-blind placebo-controlled clinical trial. Arthritis Research & Therapy. December 16, 2009.
(20) Ellulu, Mohammed S et al. “Effect of vitamin C on inflammation and metabolic markers in hypertensive and/or diabetic obese adults: a randomized controlled trial.” Drug design, development and therapy. July 2015.
(21) Henmi, Hirofumi et al. “Effects of ascorbic acid supplementation on serum progesterone levels in patients with a luteal phase defect.” Fertility and sterility. 2003.
(22) Kianbakht, S. et al. Improved glycemic control in patients with advanced type 2 diabetes mellitus taking Urtica dioica leaf extract: a randomized double-blind placebo-controlled clinical trial. Clinical Laboratory. 2013.
(23) Suzuki, T. et al. Role of flavonoids in intestinal tight junction regulation. The Journal of Nutritional Biochemistry. May 2011.
(24) Shigeshiro, M. et al. Dietary polyphenols modulate intestinal barrier defects and inflammation in a murine model of colitis. Journal of Functional Foods. April 2013.
(25) National Institute of Heart, Lung, and Blood Institute. Idiopathic Pulmonary Fibrosis | NHLBI, NIH. National Institutes of Health website. Accessed April 15, 2020.
(26) Marchioni, A. et al. Acute exacerbation of idiopathic pulmonary fibrosis: lessons learned from acute respiratory distress syndrome? Critical Care. 2018.
(27) Associated Press. Some doctors moving away from ventilators for virus patients. APnews.com. April 8, 2020.
(28) Veith, C. et al. The disturbed redox-balance in pulmonary fibrosis is modulated by the plant flavonoid quercetin. Toxicology and Applied Pharmacology. December 1, 2017.
(29) Ramyaa, Periasamy et al. “Quercetin modulates OTA-induced oxidative stress and redox signalling in HepG2 cells – up regulation of Nrf2 expression and down regulation of NF-κB and COX-2.” Biochimica et biophysica acta. 2014.
(30) Ma, Q. Role of Nrf2 in Oxidative Stress and Toxicity. Annual Review of Pharmacology and Toxicology. December 16, 2015.
(31) Liu, Q. et al. Role of Nrf2 and Its Activators in Respiratory Diseases. Oxidative Medicine and Cellular Longevity. January 8, 2019.
(32) Wu, W. et al. Quercetin as an Antiviral Agent Inhibits Influenza A Virus (IAV) Entry. Viruses. January 2016.
(33) Mlcek, J. et al. Quercetin and Its Anti-Allergic Immune Response. Molecules. May 2016.
(34) CBC Radio. As coronavirus spread speeds up, Montreal researchers will trial an anti-viral treatment for COVID-19 in China. CBC.ca website. February 28, 2020. Last updated March 13, 2020.
(35) Zemmouri, H. et al. Urtica dioica attenuates ovalbumin-induced inflammation and lipid peroxidation of lung tissues in rat asthma model. Pharmaceutical Biology. April 7, 2017.
(36) Garg, S. et al. Hospitalization Rates and Characteristics of Patients Hospitalized with Laboratory-Confirmed Coronavirus Disease 2019 — COVID-NET, 14 States, March 1–30, 2020 | MMWR. MMWR and Morbidity and Mortality Weekly Report. April 17, 2020.
(37) Qayyum, R. et al. Mechanisms underlying the antihypertensive properties of Urtica dioica. Journal of Translational Medicine. September 1, 2016.
(38) Vajic, U. J. et al. Urtica dioica L. leaf extract modulates blood pressure and oxidative stress in spontaneously hypertensive rats. Phytomedicine. July 15, 2018.
(39) Traber, M. G., & Stevens, J. F. Vitamins C and E: Beneficial effects from a mechanistic perspective. Free Radical Biology and Medicine. 2011.
(40) Hemilä, H., & Louhiala, P. Vitamin C may affect lung infections. Journal of the Royal Society of Medicine. November 2007.
(41) Galelli, A. & Truffa-Bachi, P. Urtica dioica agglutinin. A superantigenic lectin from stinging nettle rhizome. Journal of Immunology. August 15, 1993.
(42) Carr, A. C. & Maggini, S. Vitamin C and Immune Function. Nutrients. November 3, 2017.
(43) Wolska, J. et al. Influence of temperature and brewing time of nettle (Urtica dioica L.) infusions on vitamin C content Roczniki Państwowego Zakładu Higieny. 2016.