Several natural products have shown potential benefit for allergic rhinitis in one or more preliminary controlled trials. These include a water-extract of
, a freeze-dried extract of stinging
an extract of soy sauce (Shoyu polysaccharides),
and , <72> rosmarinic acid (a substance found in the herb
and many other herbs, including
herbal formula containing
Traditional Chinese herbal medicine
has shown some promise for allergies as well.
Another traditional Chinese treatment,
, is commonly recommended for allergies, but a controlled trial of 40 people failed to find significantly more benefit with real acupuncture than with fake acupuncture.
However, another study found benefit with real acupuncture plus real traditional Chinese herbs as opposed to placebo acupuncture and nonspecific Chinese herbs.
A carefully conducted review of 7 placebo-controlled trials failed to find convincing evidence for acupuncture’s effectiveness against allergic rhinitis.
One rather unusual study tested a nasal spray containing capsaicin, the “hot” in
and other hot peppers.
It is not clear how practical this is—researchers had to use local anesthetic in the nose prior to using the spray!
Highly preliminary evidence suggests
may counter allergic reactions of the type involved in hay fever.
A sizable (112-participant) double-blind study of
at a dose of 800 mg daily for hay fever found modest benefits at best.
A smaller study failed to find any benefits.
A 12-week, double-blind, placebo-controlled study of 40 people tested the supplement
conjugated linoleic acid
(CLA) as a treatment for people with allergies to birch pollen and found some evidence of benefit.
is often suggested as a treatment for allergies, but the research results are preliminary and somewhat contradictory.
Test tube studies suggest that flavonoids—biologically active compounds found in many plants—may help reduce allergy symptoms.
A particular flavonoid,
, seems to be one of the most active.
Many texts on natural medicine claim that quercetin works like the drug cromolyn (Intal), by stopping the release of allergenic substances in the body. However, while we have direct evidence that cromolyn is effective, there have not been any published studies in which people were given quercetin and their allergic symptoms decreased. It is a long way from test tube studies to real people.
Tomato extract has been advocated for the treatment of allergic rhinitis, but the one double-blind study said to demonstrate benefit actually proves almost nothing at all due to major flaws in its statistical analysis.
Oligomeric Proanthocyanidins (OPCs)
from grape seed or pine bark are also often said to be effective. However, an 8-week, double-blind trial of 49 individuals found no benefit from grape seed extract (dose not stated).
The last several substances discussed (vitamins E and C, flavonoids, and OPCs) are
. One study failed to find evidence of benefit with a mixture of antioxidants: beta-carotene (9 mg/day), vitamin C (1500 mg/day), vitamin E (130 mg/day), zinc (45 mg/day), selenium (76 mg/day), and garlic (150 mg/day).
methyl sulfonyl methane (MSM)
are sometimes recommended for hay fever, but there is as yet no significant evidence that they are effective.
A 2009 review of 6 high-quality trials with over 1,000 children found that neither omega-3 nor omega-6 oil consumption prevented allergic diseases in high-risk children. Allergic diseases included eczema, asthma, allergic rhinitis or food allergy; and omega-3 and omega-6 sources included
gamma-linolenic acid (GLA)
, canola oil, and borage oil.
It has often been suggested that consumption of
can reduce symptoms of hay fever. However, the one published study designed to test this suggestion failed to find benefit.
Another study failed to find the bee product
Acupuncture has also shown some promise for allergic rhinitis.
In a randomized, placebo-controlled trial enrolling 80 adult subjects, real acupuncture was superior to sham acupuncture after 8 weeks of treatment for symptoms of persistent allergic rhinitis.
In one study,
appeared to provide some benefits.
This topic is also discussed in the
database, under the chapter on hay fever.
Helminth therapy involves infecting a person with a type of worm, like hookworms or whipworms, that live in the human intestines. It is thought that this type of therapy can help the body adjust its immune response to allergens. A systematic review that included 2 placebo-controlled trials involving 130 patients with allergic rhinitis did not find any evidence to support the use of helminth therapy to reduce allergy symptoms.