Nutrition and Dietary Supplements
If you have any food allergies, eliminate those items from your diet. Even if you don't have any identified food allergy, reducing the intake of foods that may stimulate inflammation (such as meats, full fat dairy products, sugar, and highly processed foods) may improve your symptoms.
Although not all experts agree, bromelain supplements may help suppress cough, reduce nasal mucus associated with sinusitis, and relieve the swelling and inflammation caused by hay fever. This supplement is often administered with quercetin.
Essential Fatty Acids
Omega-6 fatty acids have a longstanding history of folk use for allergies. They are essential fatty acids (EFAs), meaning that they are needed by the body and must be obtained from the diet. People who are prone to allergies may require more EFAs and often have difficulty converting linoleic acid (an inflammation-provoking type of omega-6 fatty acid) to gamma-linolenic acid (GLA; an anti-inflammatory omega-6 fatty acid). In fact, women and infants who are prone to allergies appear to have lower levels of GLA in breast milk and blood. Studies on the use of EFAs to prevent allergic reactions or reduce their magnitude have had mixed results. Whether taking a GLA supplement improves your symptoms, therefore, may be very individual. Work with your healthcare provider to first determine if it is safe for you to try GLA and then follow your allergy symptoms closely for any signs of change. GLA is found in spirulina and seed oils of evening primrose, black currant, borage, and fungal oils.
In terms of dietary changes relative to EFAs, you should try to eat foods rich an omega-3 fatty acids (such as cold-water fish, flaxseeds, and walnuts). Eating foods rich in omega-3 fatty acids and limiting foods with omega-6 fatty acids (found, for example, in egg yolks, meats, and cooking oils including corn, safflower, and cottonseed,) may reduce allergy symptoms in general. This is because omega-3 fatty acids tend to decrease inflammation while omega-6 fatty acids (other than GLA) tend to increase inflammation.
Studies suggest that L. acidophilus , "friendly" bacteria found in the intestines, enhance the immune system. It is thought to have the potential to lower the risk of allergies, including allergic rhinitis.
Cysteine is an essential amino acid found in many proteins. N-acetylecysteine (NAC), a modified form of cysteine, may reduce nasal congestion. Theoretically, therefore, taking an NAC supplement may help reduce symptoms of allergic rhinitis. This theory needs scientific study before specific recommendations can be made.
Quercetin is a flavonoid, a plant pigment responsible for the colors found in fruits and vegetables. Quercetin inhibits the production and release of histamine -- a substance that contributes to allergy symptoms of allergic rhinitis, such as a runny nose and watery eyes. Quercetin seems to work better when used in conjunction with bromelain, a digestive enzyme found in pineapples.
Test tube and animal studies suggest that spirulina, an immune system stimulant, may help protect against harmful allergic reactions. It appears that spirulina prevents the release of histamines, substances that contribute to symptoms of allergic rhinitis. Research on people is needed.
Information on vitamin C for allergic rhinitis is somewhat limited, but early studies suggest that there may be a role for this vitamin in treating symptoms of hay fever and year-round allergic rhinitis.
Butterbur ( Petasites hybridus )
Butterbur has been traditionally used to treat asthma and bronchitis and to reduce mucus. A recent study of 125 people with hay fever found that an extract of this herb was as effective and less sedating than cetirizine, a commonly prescribed non-sedating antihistamine. The study lasted only 2 weeks, and while it shows promise, it is not known what would be the effect of using butterbur over a longer time period.
Echinacea ( Echinacea angustifolia/Echinacea pallida/Echinacea purpurea )
Several test tube and animal studies suggest that echinacea contains substances that enhance the activity of the immune system and reduce inflammation. For these reasons, professional herbalists may recommend echinacea to treat allergic rhinitis. In rare cases, however, echinacea itself causes an allergic reaction. See Warnings and Precautions.
Evening Primrose ( Oenothera biennis )
This herb is considered by some to be a potential treatment for allergic rhinitis because the main active ingredient in it is gamma-linolenic acid (GLA), an essential fatty acid that may relieve allergy symptoms (see Nutrition and Dietary Supplement section).
Goldenseal ( Hydrastis canadensis )
Goldenseal is considered to be a natural antibiotic and antiseptic, and many herbalists include it in herbal remedies for allergic rhinitis. Laboratory studies suggest that berberine, the active ingredient in goldenseal, has antibacterial and immune-enhancing properties. Commercial preparations of goldenseal have very little berberine, however. Therefore, it is unclear whether it is berberine, another substance, or a combination of factors in goldenseal that may be providing the benefit reported by herbal experts.
Stinging Nettle ( Urtica dioica/Urtica urens )
Stinging nettle has traditionally been used for treating a variety of conditions, including allergic rhinitis. Studies thus far have been favorable, but not overwhelmingly so. More research is needed, but you may want to talk to your doctor about whether it is safe for you to try nettle as a possible alternative treatment.