According to the CDC allergies are the 6th leading cause of chronic illness in the U.S.
The American Academy of Allergy Asthma & Immunology reports that the prevalence of allergic diseases in the industrialized world has continued to rise for more than 50 years. Roughly 8% of U.S. adults have hay fever and 8% of children have a food allergy.
What is an Allergy?
An allergy is an over-reaction of the immune system to a substance in the environment that causes little or no problem for the majority of the population.
The body reacts to an allergen by making antibodies and releasing inflammatory compounds such as histamines. The inflammatory process results in a variety of unpleasant symptoms.
Different Types of Allergies
Allergic rhinitis is an inflammation of the nasal tissue caused by an airborne allergen. Symptoms include stuffy nose, runny nose, sneezing, watery eyes and itching. There are 3 main types of allergic rhinitis:
- Hay fever or seasonal allergic rhinitis is a reaction to mold spores or pollens from trees, grasses or weeds.
- House dust mite allergy is a reaction to proteins in the excrement of dust mites, microscopic organisms that thrive in warm houses.
- Pet allergies are a reaction to dander (flaky, dead skin cells) from mammals, most commonly from cats.
A food allergy is an abnormal immune response to a particular food. According to the FDA, these 8 most common allergenic foods account for 90% of food allergic reactions.
- Crustacean shellfish
- Tree nuts
Food allergy symptoms range from mild to severe. They can include a raised itchy rash (hives), swelling of the face, difficulty swallowing, an itchy mouth, vomiting, abdominal pain, wheezing or shortness of breath.
People can have allergic reactions to a wide variety of triggers including medications, insect stings, environmental chemicals, food additives, latex and cockroaches.
7 Research-Based Remedies for Allergies
The intestinal microbiome performs a critical role in the development of immune tolerance. Research has shown that certain strains of gut bacteria can help to prevent the immune system from overreacting to non-harmful substances. When these bacteria are not present in the gut microflora, allergic reactions are more likely to occur.
Using probiotics to increase the amount and diversity of beneficial bacteria could be helpful in treating a range of allergies and autoimmune diseases.
A study analyzed data from 1,879 participants in the American Gut Project to determine the association between gut microbial population and the risk of allergies in adults. The participants provided fecal samples and filled in questionnaires about their allergies. More than 80% of subjects reported reactions to at least one allergen.
People with allergies, especially to nuts and seasonal pollen, had markedly fewer bacteria species in their fecal microbiota than people without allergies. Their microbiota showed a reduction in Clostridiales and an increase in Bacteroidales. Researchers noted that this bacterial imbalance could be targeted to improve treatment or prevention of allergies.
A randomized controlled trial published in the American Journal of Clinical Nutrition tested whether a combination of probiotics could improve quality of life for people with seasonal allergies. During the spring allergy season, 173 participants were randomized into 2 groups. The treatment group received a supplement containing Lactobacillus gasseri, Bifidobacterium bifidum and Bifidobacterium longum. The control group received a placebo supplement.
Throughout the 8-week study, participants completed daily and weekly questionnaires that asked about their allergy symptoms and how those symptoms affected their activities at home and at work. Over the course of the study, the probiotic group showed a significant improvement in quality of life scores compared with the placebo group. The probiotic group also reported a significant decrease in symptoms such as sneezing, stuffy nose and runny nose.
A randomized controlled trial published in the Journal of Allergy and Clinical Immunology evaluated the use of the probiotic Lactobacillus rhamnosus in combination with oral immunotherapy for treating peanut allergy. Oral immunotherapy involves feeding allergic people very small doses of peanut protein and gradually increasing the amount.
A total of 56 allergic children were randomized to receive either the combination therapy or a placebo. After 18 months of treatment, 82% of children in the probiotic group had no allergic reaction to peanuts compared to less than 4% in the placebo group.
A follow-up study published in the Lancet found that 67% of the original participants who received combined treatment with probiotics were still eating peanuts 4 years later. Four of the treated children had experienced an allergic reaction to peanuts, but none had an anaphylaxis (life threatening) reaction.
Method: Increase the beneficial microbes in your gut by consuming naturally fermented foods such as yogurt, kefir, sauerkraut, kimchee or tempeh.
Before buying yogurt, read the label to ensure it contains live, active cultures. Many commercial brands are pasteurized, a process that destroys good bacteria along with the bad.
If you use probiotic supplements, take them on an empty stomach and wait at least 30 minutes before eating. This will reduce the chance of bacteria being destroyed by stomach acid.
Omega-3 essential fatty acids have protective effects in inflammatory diseases including allergies.
Research suggests a causal relationship between decreased intake of omega-3 in modern diets and an increasing number of people with allergic diseases. Laboratory tests have shown that omega-3 DHA reduces levels of immunoglobulin E, an antibody that is critical for the onset and maintenance of allergic diseases.
A study published in the European Journal of Clinical Nutrition investigated the association of omega-3 polyunsaturated fatty acids with allergic sensitization and allergic rhinitis. A total of 568 adult participants were interviewed 3 times about their food intake over the previous 24 hours. Researchers used this data to calculate their average dietary intake of essential fatty acids.
Blood tests were used to detect participants’ sensitivity to common allergens including cat and dog dander, pollen and dust mites. Participant’s blood was also tested for levels of fatty acids.
Subjects with the highest levels of EPA (a type of omega-3 found in fish oil) in their blood were significantly less likely to be sensitive to allergens or to suffer from allergic rhinitis. A higher dietary intake of ALA (a type of omega-3 found in nuts) was also associated with a decreased risk of allergic sensitization and allergic rhinitis.
A randomized controlled trial published in Clinical and Experimental Allergy examined the effects of fish oil on the early development of allergies. Researchers randomly assigned 420 infants into 2 groups. The treatment group received fish oil supplements containing 280 mg DHA and 110 mg EPA. The control group were given a placebo.
After 6 months, infants in the fish oil group had significantly higher levels of DHA and EPA and lower levels of omega-6 arachidonic acid. Analysis of blood samples showed that they also had significantly lower allergic responses to house dust mites and milk proteins.
Method: Increase your intake of oily fish such as salmon, trout, mackerel, herring and sardines.
You can also boost your levels of omega-3 by taking a daily supplement containing DHA and EPA. Choose from fish oil, cod liver oil, krill oil or algae oil.
Avoid supplements labeled Omega 3-6-9. If you eat a standard modern diet, you are probably already getting too much omega-6. Omega-9 (found in olive oil) is not an essential fatty acid.
3. Mediterranean Diet
A Mediterranean diet, rich in fruits and vegetables and low in omega-6 fats, has been associated with a lower prevalence of asthma and allergies. This could be due to antioxidants in the fruits and vegetables which seem to have a protective effect.
The use of olive oil in place of vegetable oils and margarine, along with higher consumption of fish, may also help to lower the incidence of allergies by reducing inflammation caused by an imbalance of omega-3 and omega-6 fatty acids.
A study published in the BMJ journal Thorax examined whether high consumption of fresh fruit and vegetables, typical of a Mediterranean diet, could be protective against allergies and asthma. Researchers collected data from 690 children aged 7–18 on the Greek island of Crete. Parents completed a questionnaire on their child’s allergic and respiratory symptoms along with 58-item food frequency questionnaire. The children underwent skin prick tests with 10 common airborne allergens.
A daily intake of grapes, oranges, apples and fresh tomatoes had a protective effect against wheezing and allergic rhinitis. Children who consumed nuts more than 3 times a week were also less prone to wheezing. In contrast, consumption of margarine raised the risk of wheezing and allergic rhinitis.
A study published in the journal Allergy assessed whether a Mediterranean diet for mothers and their children reduced childhood asthma and allergic rhinitis. Researchers collected data on the food intake of 1, 476 Mexican children over 12 months via questionnaires given to parents. They also used questionnaires to assess the mother’s food intake during pregnancy. Data on childhood symptoms was obtained through an asthma and allergies questionnaire.
For children, greater adherence to a Mediterranean diet including vegetables, legumes, fruits, nuts, cereal and fish was associated with having less asthma, wheezing, allergic rhinitis, sneezing and itchy-watery eyes. Children with the highest adherence to the diet reduced their risk of asthma by 60% and their risk of allergy symptoms by 21-36%.
Method: There are different versions of the Mediterranean diet, but here are some general guidelines:
- Maximize your intake of vegetables, legumes and fruits
- Switch to wholegrain bread and pasta
- Increase the amount of fish in your diet (especially oily fish) and limit red meat
- Use olive oil in place of high omega-6 fats such as corn oil or margarine
- Snack on fruit and nuts
- Avoid fast food and processed food
- Enjoy an occasional glass of red wine with dinner
4. Vitamin D
Since the 1960s, the incidence of allergic diseases has increased worldwide, with industrialized countries at higher absolute latitudes (furthest away from the equator) having the highest prevalence.
One theory to explain this phenomenon is vitamin D deficiency. As populations become more prosperous and more westernized, more time is spent indoors. Less exposure to sunlight results in lower vitamin D levels.
Vitamin D plays an important role in immune function. Research has shown that the vitamin activates regulatory cells that inhibit the release of chemicals that cause or worsen allergies, so allergies are more likely to occur in people who are vitamin D deficient. Furthermore, vitamin D deficiency can alter the composition of gastrointestinal microbiota, leading to an imbalance in the immune system.
Researchers at Harvard Medical School conducted a study to estimate the incidence of anaphylaxis (a potentially life-threatening allergic reaction) throughout the United States. They analyzed a billing database including 24 pediatric hospitals in 18 states for all patient encounters billed as anaphylaxis over a 5-year period. They then divided the hospitals geographically along a north-south line extending roughly from Washington, DC to Sacramento, California.
Anaphylaxis cases caused by food, serum, immunization and other allergens were all more common in the northern hospitals. The north had double the cases of food allergy anaphylaxis compared with the south. Researchers suggest that this north-south gradient might be due to differences in vitamin D status.
An Australian study published in the Journal of Allergy and Clinical Immunology investigated the role of vitamin D in the development of childhood food allergy. Melbourne, the major Australian city furthest from the equator, has the highest reported prevalence of infantile food allergy in the world. Researchers recruited 5,276 infants attending one-year-old immunization sessions in Melbourne clinics. The children were given skin-prick tests for 4 common food allergens. Blood tests were used to determine vitamin D levels.
Australian children with vitamin D insufficiency were 3 times more likely to be allergic to eggs and 11 times more likely to be allergic to peanuts. They were also more likely to have multiple food allergies compared with children with sufficient levels of vitamin D. Researchers concluded that vitamin D sufficiency may be an important protective factor for food allergy during the first year of life.
Method: If you live in a Northern climate, aim to expose your skin to sunlight for at least 15 minutes a day between April and September.
To keep your vitamin D levels up during the winter, consider taking a daily supplement. Cod liver oil is a good source of vitamin D as well as omega-3.
Quercetin is a polyphenol from the flavonoid group. It is found in varying quantities in a wide range of plant foods including apples, red onions, sweet potato, kale, cranberries and blueberries.
Research has shown that quercetin has antioxidant and anti-inflammatory properties. It also inhibits the release of histamines during exposure to allergens. Histamines are known to trigger allergy symptoms such as itching, sneezing, runny nose and watery eyes.
A Japanese study assessed the effect of apple polyphenols on clinical symptoms of persistent allergic rhinitis. The 33 patients enrolled in the study were allergic to house dust mites and had experienced moderate or severe symptoms for at least 3 years. The participants were randomized into 3 groups.
The low-dose group received a drink containing 50 mg of apple polyphenols. The high-dose group received a drink containing 200 mg of apple polyphenols. The control group received a placebo. Patients had one drink a day for 4-weeks.
Nasal signs and symptoms were scored independently before and after treatment using a 4-point scale. Consumption of apple polyphenols led to greater improvements in nasal discharge, sneezing attacks and swelling in the nasal passages compared with the placebo. Nasal discharge improved more in the high-dose group than the low-dose group.
A study published in Acta Bio Medica tested the efficacy of a quercetin supplement for relief of seasonal allergic rhinitis symptoms. At the beginning of the study, the 23 subjects had nasal and eye symptoms typical of seasonal allergic rhinitis. They also tested positive for pollen allergy. Participants were given a supplement containing quercetin along with vitamin D and Perilla frutescens (an Asian herb traditionally used for respiratory complaints).
After one month of supplementation, patients showed a 70% reduction in total symptom scores and had reduced their use of anti-allergic drugs by 73%. They had highly significant reductions in symptoms of sneezing, runny nose, stuffy nose, itchy eyes, watery eyes and red eyes.
Method: You should be able to achieve 50 mg a day of quercetin by including a wide variety of fresh fruits and vegetables in your diet. According to the USDA, a whole apple, eaten with the skin on, contains about 4 mg of quercetin per 100 grams, so a medium apple could contain up to 10 grams. Red onions contain 32 mg of quercetin per 100 grams, kale contains 23 mg, cranberries contain 15 mg and sweet potato contains 10 mg.
The recommended dose for hay fever is 400 mg twice a day in between meals. For general maintenance, you can take 100-250 mg of quercetin up to 3 times a day.
If it is difficult for you to obtain quercetin from diet alone, you can take a supplement during allergy season.
6. Stinging Nettle
Stinging nettle is an old folk remedy for hay fever.
Laboratory tests have shown that nettle extract inhibits several key inflammatory events that cause the symptoms of seasonal allergies. In particular, it reduces the amount of histamine the body produces in response to an allergen. Some doctors recommend taking freeze-dried stinging nettle supplements before the start of hay fever season.
A clinical trial published in Planta Medica assessed the efficacy of stinging nettle supplements for treating hay fever symptoms. A total of 69 volunteers were randomized into 2 groups. The treatment group were given 300 mg of freeze-dried stinging nettle capsules and the control group were given a placebo. All participants were told to take 2 capsules upon onset of hay fever symptoms and to record their responses within 1 hour. Subjects took an average of 18 doses during the trial period.
In the stinging nettle group, 32% reported dramatic improvement and 84% reported moderate improvement in at least 1 symptom (runny nose, stuffy nose or watery eyes). When asked to make an overall assessment of the nettle supplement, 58% rated it as moderately or highly effective. When asked to compare it to other hay fever medicines, 48% rated it as the same or more effective.
Method: You can ingest stinging nettle as a food, as a tea or in a supplement capsule.
- Wearing gloves, pick the tops of young nettles before they begin to form flowers. Cooking the nettles neutralizes their sting. Use them like spinach in soups, stews or pasta dishes.
- To make nettle tea, stir a tablespoon of dried nettle leaf into 8 ounces of boiling water. Steep for about 10 minutes, then strain into a cup.
- Nettle supplement capsules can range from 200 mg to 900 mg, so follow the dosage instructions on the label. Do not take nettle supplements if you are pregnant or breast-feeding.
The herb butterbur has been used as a folk remedy for allergies and asthma.
Laboratory tests have shown that the active ingredient in butterbur, petasin, blocks the action of leukotrienes, inflammatory chemicals involved in allergic reactions. Trials on patients with allergic rhinitis have shown that butterbur is just as effective as antihistamine drugs.
A study published in Phytotherapy Research compared butterbur extract to the pharmaceutical antihistamine fexofenadine (Allegra) for treating allergic rhinitis. Researchers randomized 330 people with hay fever into 3 groups. One group was given butterbur supplement tablets, the comparison group received fexofenadine tablets, and the control group was given a placebo.
Butterbur and fexofenadine were both significantly superior to the placebo in improving allergic rhinitis symptoms. The herbal supplement was just as effective as the pharmaceutical drug, with no significant difference in symptom improvement.
Another randomized controlled trial published in the BMJ compared the efficacy and tolerability of butterbur with the pharmaceutical antihistamine cetirizine (Zirtec). Researchers recruited 125 outpatients who had been diagnosed with seasonal allergic rhinitis. Subjects were randomized to receive either butterbur tablets or cetirizine tablets for 2-weeks. At the beginning and end of treatment, patients filled in symptom questionnaires. They also had a full medical examination and laboratory tests.
Improvement in symptom scores was similar in butterbur and cetirizine treatment groups for all items tested. Clinical assessment scores were also the same for patients in both groups. Some patients in the cetirizine group reported side effects of drowsiness and fatigue. The researchers recommend that butterbur should be considered when the sedating effects of antihistamines must be avoided.
Method: When purchasing butterbur supplements, check the label for phrases like ‘free of pyrrolizidine alkaloids’ or ‘PA free’. Pyrrolizidine alkaloids (PAs), found in some butterbur products, can damage the liver or lungs if ingested.
If you take steps to control your allergies with natural remedies, you may see a range of other health benefits. By ensuring that you get sufficient vitamin D and adopting a diet that includes probiotics, oily fish and a variety of fruits, vegetables and nuts, you can boost your immune system and lower your risk for a range of inflammatory diseases including heart disease and diabetes.
If you take prescription or over-the-counter antihistamines and experience unwanted side-effects, it may be worth experimenting with herbal alternatives. Keep a daily symptoms diary to discover which remedies work best for you.