Quercetin – A Natural Anti-Histamine to manage Hay Fever

seasonal allergies

Quercetin – A Natural Anti-Histamine To Manage Hay Fever

Hay fever can put an absolute downer on spring and summer, especially when after months of lockdown, all you want to do is be outside enjoying the warmer weather. A runny nose, itchy eyes, scratchy throat, irritating tickly cough and even skin rashes and hives, can all put a big dampener on this newfound freedom.

In fact, according to Allergy UK, “Hay fever is the most common form of non-infectious rhinitis, affecting between 10% and 30% of all adults and as many as 40% of children’”.[1] Up to 57% of adult patients and up to 88% of children with Allergic Rhinitis (AR) have sleep problems, including micro-arousals, leading to daytime fatigue and somnolence, and decreased cognitive functioning.1

But it’s not just hay that triggers these symptoms. “Hay fever” is more correctly called Seasonal Allergy or Allergic Rhinitis, as early-season sufferers tend to react to a variety of different tree pollens, such as alder, ash, birch, hazel and oak that are carried in the wind whereas late seasonal allergy sufferers react more to specific grass and agriculture crop pollens, such as rapeseed oil, which start to emerge early May and continue to around mid-August. During this time weeds such as nettle and mould spores are also released making these high summer months a veritable cocktail of nature’s allergens!  

Seasonal allergies & the histamine response

So how does pollen cause these symptoms and how can we manage these types of allergies?

Histamine is a natural substance produced by the body and plays an important role in different systems including the immune system. Here it is stored in mast cells, found in high levels in the gut, airways and nasal lining, and released as part of a natural response to what your body perceives to be an allergen, be it from pollen, food or dust. For some people this does not cause symptoms but for an increasing number of people histamine is either over produced or cannot be broken down properly in the body; it is the histamine build-up that causes allergic rhinitis symptoms, as well as other symptoms such as headaches, diarrhoea, bloating stomach, asthma and red, itchy skin. This is why seasonal allergies can partly be linked to “histamine intolerance”.

What causes high histamine?

Once histamine is produced in the body, it is either stored or broken down by enzymes. Histamine N-methyltransferase (HMT) is the enzyme that breaks down histamine inside cells, while diamine oxidase (DAO) is the main enzyme used to break down histamine ingested in the diet (certain foods either contain histamine or can trigger a histamine response – see below) and breaking down histamine after it has been released from cells (e.g. in the upper respiratory tract or nose – think itchy eyes and sneezing – both are a result of histamine release).

Some people, however, lack one or both of these enzymes, resulting in systemic overload and histamine intolerance. That’s why many people don’t just experience seasonal allergies, but this profile tends to go hand in hand with an increased risk of food allergies, asthma and other high histamine issues such as Irritable Bowel (IBS) type symptoms.

Managing histamine intolerance & hay fever

DAO is the predominant enzyme that people tend to lack and it is due to a number of reasons including:

  • Genetic mutations,
  • Certain medications,
  • Certain diseases (especially gut related)
  • DAO-blocking foods and beverages.

Foods to avoid

The main high histamine food culprits are those products that are aged and fermented. These include wine, beer, aged cheeses, vinegars, smoked meats/fish; as well as artificial additives including sulphites and nitrites.

High histamine foods – Avoid consuming: Alcohol, especially wine, beer and ciderFermented foods such as sauerkrautAged cheeses such as parmesan and blue cheeseVinegarSoy sauceReady made-mealsDried fruitProducts that contain wheat and yeastSmoked and processed meatTinned and smoked fish  Foods that stimulate the release of histamine in immune cells – Avoid consuming: Tomato and tomato saucesChocolate and cocoaCitrus fruit and strawberriesDairy yoghurtAdditives in processed foods including benzoate, sulphites, nitrites,glutamate, and food dyesChickpeasPeanuts and walnuts  Foods that block DAO – Avoid consuming: Alcohol, Energy drinks, Black and green tea  

Avoiding histamine foods for a period of time is one of the best ways to see if you react to histamine, as allergy symptoms will subside if they’re due to histamine intolerance.

Natural Anti-Histamines

The most common marketed hayfever medications are anti-histamines; but these drugs can causes symptoms of drowsiness and fatigue, as well as not getting to the root of the hayfever problem – why has an allergy developed in the first place? This is a where a functional medicine approach, including using directed nutrients, can support the body in a more natural way.


Quercetin is an antioxidant plant pigment from the flavonoid family of phytonutrients and is often referred to as “nature’s antihistamine”. It is found in many plants, fruits and vegetables including onions, green tea, apples, cherries, broccoli, tomatoes, berries and green tea. Flavonoids are known for their antioxidant activity and support a wide range of health benefits including the immune system’s response to allergens.

Quercetin actually helps to stabilise mast cell walls, which in turn helps prevent the release of histamine and reduces the likelihood of seasonal allergy/histamine intolerance symptoms. For those with seasonal allergies, quercetin supplements are recommended to increase protection over and above food-derived sources.

But that’s not all! Quercetin is a potent antioxidant bioflavonoid that research shows:

  • Positively effects gastrointestinal function by reducing inflammation, improve gut microbiota levels, enhance intestinal barrier function and provide an overall protective effect.[2]
  • Prevents neuroinflammation in the case of neurodegenerative disease such as Parkinson’s disease and Alzheimer’s disease.[3]
  • Has protective affects against cancer tumour growth.3
  • Has anti-inflammatory effects against pro-inflammatory cyclooxygenase enzymes, which reduce the use of NSAIDs (Non-Steroidal Anti-Inflammatory Drugs) like aspirin that cause gastric ulcer and increase the risk of stroke.[4]
  • Prevents cardiovascular disease through strengthening and dilation of blood vessels, as well as reduction of inflammation within the cardiovascular system.[5]
  • Reduces fat accumulation in adipose tissue supporting a role in reducing metabolic syndrome and liver disease.[6]
  • Has a gastroprotective role against strains of bacteria such as H.pylori responsible for casuing gastric ulcers.[7]

Vitamin C

Vitamin C is something we often think of for colds or illness prevention, but it can have a significant impact on allergies as well. Vitamin C positively impacts allergies from a variety of angles:

  • It helps to stabilise mast cells.[8]
  • Supports histamine breakdown and promotes immune system balance.[9]
  • Reduces immune cell infiltration into challenged tissues like the lungs and sinus membranes.[10]

Vitamin C can be found in fresh food sources such as vegetables and fruits but is often required at higher doses than the daily diet can provide to support the immune system, especially during allergy season. For this reason, the mixed ascorbate form of Vitamin C can be taken at doses from 1g upwards, without the laxative effect that larger doses of the ascorbic acid form of Vitamin C can result in. Better still is a liquid form of Vitamin C using a soy-free liposome delivery system that has superior absorption.

Vitamin D3

Vitamin D3 is often used to support the function of the immune system for illness prevention, but in addition this sun-derived vitamin also improves the regulatory function of the immune system, balancing the allergic response in conditions such as hayfever as well.[11]

Vitamin D is a fat-soluble nutrient so unless you’re lucky enough to have had a month in the sunshine over the long UK winter months, you are likely to have low levels of this important nutrient in your body as we enter allergy season. Food sources, such as eggs, mushrooms and oily fish, provide some Vitamin D but the body requires sunshine to manufacture the levels from the skin that we need to support immune function. It’s therefore common for adults and children in the UK to require some form of Vitamin D supplement (ranging from between 1000 to 5000iu for adults) to see them through the winter months and importantly support immune health into the spring and summer.

Many Vitamin D3 products and Vitamin D3 dietary sources are derived from animal sources so are not suitable for vegans, or indeed acceptable for some vegetarians but there are now vegan Vitamin D3 supplements derived from plant-based sources.

Probiotics & seasonal allergies

The gut is extremely sensitive to histamine signalling and levels and the gut microbiome plays a multi-layered role in the development of histamine intolerance and allergies. Simply reducing the intake of foods that cause inflammation, such as gluten and dairy, can help to reduce the inflammatory response overall and mitigate allergies. Foods such as dairy and gluten can also worsen mucus symptoms as the body responds in a protective fashion by increasing mucus secretions.

As discussed above, reducing the intake of high histamine foods may also help reduce the body burden of histamine and can have a significant impact on allergies for some individuals.

Intestinal dysbiosis occurs when the effects of unfriendly bacteria outweigh the beneficial probiotic bacteria. Factors that can promote dysbiosis include antibiotics, steroids including birth control pills, alcohol, bacterial infections, stress, travelling or a poor diet. This state of gut bacteria imbalance can be a key driver for dysregulated gut and histamine response leading to immune system dysfunction. So when addressing seasonal allergies taking a good quality probiotic supplement alongside the dietary and other nutritional measures can help ease symptoms.

What next?

The key to any natural approach when addressing seasonal allergies is to be prepared. In order to support the body’s histamine balance and immune system, preparation for beating seasonal allergy symptoms needs to start now. Look at addressing diet and adding in specific natural anti-histamine nutrients into your supplement regime to fully enjoy the spring and summer holidays that are just around the corner.

Dr Elisabeth Philipps PhD BSc (Hons) BSc Nutr Med AFMCP

Dr Elisabeth Philipps is a clinical neuroscientist and functional medicine practitioner and runs a health consultancy specialising in brain health, the endocannabinoid system and phytocannabinoids including C*B*D. She regularly presents at conferences and events and provides expert opinion for the national press, specialist healthcare publications and health companies. You can connect with Elisabeth via:

www.drelisabethphilipps.com | instagram – @drelisabethphilipps | Twitter – @drphilipps | Linked In – Dr Elisabeth Philipps

[1] Pawankar R, C. G. (2013). The WAO White Book on Allergy (Update 2013).

[2] Li Y et al (2016) Quercetin, inflammation and immunity. Nutrients 8(3):167

[3] David (2016) Overviews of Biological Importance of Quercetin: A Bioactive Flavonoid. Pharmacogn Rev. 2016 Jul-Dec; 10(20): 84–89

[4] Espley RV et al (2014) Dietary flavonoids from modified apple reduce inflammation markers and modulate gut microbiota in mice. J Nutr 144(2):146-154

[5] Porras D, et al (2017) Protective effect of quercetin on high-fat diet-induced non-alcoholic fatty liver disease in mice is mediated by modulating intestinal microbiota imbalance and related gut-liver axis activation. Free Radic Biol Med 102:188-202

[6] Singh DP et al (2017) Overcoming the exacerbating effects of ranitidine on NSAID-induced small intestinal toxicity with quercetin: providing a complete GI solution. Chem Biol Interact 272:53-64

[7] Zhang S et al (2017) Quercetin from Polygonum capitatum protects against gastric inflammation and apoptosis associated with Helicobacter pylori infection by affecting the levels of p38MAPK, BCL-2 and BAX. Molecules 22(5)

[8] Chang HH, et al. (2009) High dose vitamin C supplementation increases the Th1/Th2 cytokine secretion ratio, but decreases eosinophilic infiltration in bronchoalveolae.  J Agric Food Chem 57(21):10471-6

[9] Braga M, et al. (2011) T regulatory cells in allergy. Int J Immunopathol Pharmacol 24(1 Suppl):55S-64S

[10] Johnston CS. (1996) The antihistamine action of ascorbic acid. Subcell Biochem. 25:189-213

[11] Chambers ES, Hawrylowicz CM (2011) The impact of vitamin D on regulatory T cells. Curr Allergy Asthma Rep 11(1):29-36

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Elisabeth Philipps

Karen Devine

Karen Devine

Shelley Harvey

Related Blogs:

AllergiesHay FeverProbioticsQuercetinVitamin CVitamin D3

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