National Institutes of Health • National Center for Complementary and Alternative Medicine
Seasonal Allergies and Complementary Health Practices:
What the Science Says
There is reasonably good evidence that the technique saline nasal irrigation can be useful. Some of the other complementary practices such as the herb butterbur might be helpful, but the scientific evidence is limited or conflicting, or there is concern about the safety of the therapy. More studies are needed before researchers can say whether these approaches are (or are not) effective and safe for treating seasonal allergies.
Saline Nasal Irrigation
Saline nasal irrigation involves putting salt water into one nostril and draining it out the other. One method uses a device called a neti pot, which comes from the Ayurvedic/yoga tradition. Saline nasal irrigation also can be performed using bottles, sprays, pumps, or nebulizers. Over-the-counter nasal rinsing products that contain sterile saline (salt water) are also available.
Strength of evidence
- Much research has been conducted on saline nasal irrigation for seasonal allergy symptoms.
- Several studies have shown that saline nasal irrigation can improve nasal symptoms related to seasonal allergies in both children and adults.
- A review of the research found that nasal saline irrigation appears to demonstrate some modest clinical benefits.
- Nasal irrigation is generally safe; however, neti pots and other rinsing devices must be used and cleaned properly.
- Most important is the source of water that is used with nasal rinsing devices. According to the U.S. Food and Drug Administration, tap water that is not filtered, treated, or processed in specific ways is not safe for use as a nasal rinse. Some tap water contains low levels of organisms, such as bacteria and protozoa, including amoebas, which may be safe to swallow because stomach acid kills them. But these “bugs” can stay alive in nasal passages and cause potentially serious infections.
- Improper use of neti pots may have caused two deaths in 2011 in Louisiana from a rare brain infection that the state health department linked to tap water contaminated with an amoeba called Naegleria fowleri.
Butterbur is a shrub that grows in Europe and parts of Asia and North America, typically in wet, marshy ground. Butterbur has historically been used for a variety of health issues such as pain, headache, anxiety, cough, fever, and gastrointestinal and urinary tract conditions. It has also been used topically to improve wound healing. Today, traditional or folk uses include nasal allergies, allergic skin reactions, asthma, and migraine headache.
Strength of Evidence
- There have been several small studies of butterbur for seasonal allergies.
- An NCCAM-funded literature review reports that in a clinical trial of 125 participants, butterbur was just as effective as a commonly used oral antihistamine for allergy symptoms such as itchy eyes.
- There is some evidence that butterbur extract can decrease the symptoms associated with nasal allergies.
- Butterbur may cause allergic reactions in people who are sensitive to plants such as ragweed, chrysanthemums, marigolds, and daisies.
- Raw extracts of this herb contain toxic pyrrolizidine alkaloids, which can cause liver damage and cancer. Extracts of butterbur have been prepared that are almost completely free from these alkaloids. However, no long-term studies of butterbur products have been done, including the reduced-alkaloid products, so its long-term safety is unknown.
Some people suggest that eating honey may help to relieve seasonal allergies. The reasoning is that honey, especially if it is produced locally, could act as do-it-yourself immunotherapy; honey contains small amounts of pollen, and honey produced in a particular area probably contains the types of pollen that people who live in that area are exposed to.
Strength of Evidence
- Only a few studies have examined the effects of honey on seasonal allergy symptoms.
- There is no convincing scientific evidence that honey relieves seasonal allergies.
- Eating honey is generally safe; however, children under 1 year of age should not eat honey. People who are allergic to pollen or bee stings may also be allergic to honey.
There are suggestions from case reports and a few studies of seasonal allergy relief following acupuncture treatment. How acupuncture might work in the treatment of allergies—if it does—is unclear.
Strength of Evidence
- Only a few studies have been conducted on acupuncture for relief of seasonal allergy symptoms.
- The limited scientific evidence currently available on acupuncture has not shown clear evidence of clinically significant benefit in treating seasonal allergies.
- Relatively few complications from the use of acupuncture have been reported. Still, complications have resulted from inadequate sterilization of needles and from improper delivery of treatments.
- Practitioners should use a new set of disposable needles taken from a sealed package for each patient and should swab treatment sites with alcohol or another disinfectant before inserting needles. When not delivered properly, acupuncture can cause serious adverse effects, including infections and punctured organs.
- Researchers have studied the possibility that omega-3 fatty acids might help to prevent the development of allergic rhinitis, but a systematic review of the research found no clear evidence that they work.
- The evidence on probiotics is inconsistent, and effects may vary from one probiotic formulation to another.
- Other natural products, including astragalus, capsaicin, grape seed extract, Pycnogenol (French maritime pine bark extract), quercetin, spirulina, stinging nettle, and an herb used in Ayurvedic medicine called tinospora or guduchi, have been used to treat seasonal allergies, but the scientific evidence is insufficient to make any judgments about whether they are helpful.
NCCAM Clinical Digest is a service of the National Center for Complementary and Alternative Medicine, NIH, DHHS. NCCAM Clinical Digest, a monthly e-newsletter, offers evidence-based information on CAM, including scientific literature searches, summaries of NCCAM-funded research, fact sheets for patients, and more.
The National Center for Complementary and Alternative Medicine is dedicated to exploring complementary and alternative healing practices in the context of rigorous science, training CAM researchers, and disseminating authoritative information to the public and professionals. For additional information, call NCCAM's Clearinghouse toll-free at 1-888-644-6226, or visit the NCCAM Web site at nccam.nih.gov. NCCAM is 1 of 27 institutes and centers at the National Institutes of Health, the Federal focal point for medical research in the United States.
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