Other Herbs and Supplements
In a double-blind trial, 32 people with steroid-dependent asthma were given either placebo or
of eucalyptus for 12 weeks.
The results showed that people using eucalyptus were more able to gradually reduce their steroid dosage than those taking placebo.
Two double-blind, placebo-controlled studies enrolling a total of over 80 people with asthma suggests that
oligomeric proanthocyanidins (OPCs)
from pine bark might reduce symptoms.
An extract made from
has been advocated for the treatment of childhood asthma, but at present the meaningful supporting evidence is again limited to one placebo-controlled trial.
Another small double-blind, placebo-controlled study evaluated the effects of 4 weeks of treatment with a Japanese herbal mixture traditionally called
Researchers tested the tendency of the bronchial tubes to contract in response to an asthma-producing substance called methacholine. The results indicated that use of Saiboku-To helped prevent such contractions, and also reduced lung inflammation. Another study reportedly found benefit with a combination named Mai-Men-Dong-Tang.
Many studies have been conducted on the effects of vitamin C in treating asthma, but the evidence that it works remains inconsistent and highly incomplete.
There is only weak and/or inconsistent evidence regarding whether two antioxidants in the
might help prevent exercise-induced asthma.
One double-blind comparative study provides weak evidence that the
Ayurvedic herbal combination
called Astha 15 might be helpful for mild asthma.
is often mentioned as a treatment for asthma, but the evidence that it works is weak and contradictory at best. A double-blind study of 76 children with asthma found significant benefit from vitamin B
after the second month of usage.
Children in the treated group were able to reduce their doses of bronchodilators and steroids. However, a recent double-blind study of 31 adults who also used either inhaled or oral steroids did not show any benefit.
is also often said to be effective for asthma.
However, the scientific evidence in its favor consists almost entirely of
studies that did not attempt to eliminate the placebo effect.
Very preliminary evidence hints that the herb
may be helpful for asthma.
One study found potential benefit with the spice
Essential fatty acids, such as
gamma-linolenic acid (GLA)
and those found in
as well as
, may inhibit inflammatory responses such as those that occur in asthma. However, of the studies that tried fish oil as a treatment for asthma, most failed to find significant clinical benefit,
and one study even found that fish oil can worsen aspirin-related asthma.
Nonetheless, there is some evidence from one research group that fish oil might be helpful for exercise-induced asthma.
There is also some interesting preliminary evidence that mothers who take fish-oil during late pregnancy may reduce the risk of asthma in their children up to 16 years later.
A study of 72 children with moderate, persistent asthma found that combined or single supplementation with omega-3 oils, zinc and/or vitamin C improved their symptoms and lung function. Combined supplementation was associated with greatest improvement. The reliability of these results should be questioned, however, since about 20% of children dropped out before the end of the 38-week study.
A preliminary double-blind, placebo-controlled trial suggests that
extract might be helpful for allergic asthma.
One study suggests that the natural substance hyaluronic acid might be helpful for asthma when taken by inhalation.
Natural medicine practitioners frequently recommend the flavonoid
as a treatment for asthma. However, the only basis for this recommendation consists of a few, older, preliminary
test tube studies
that suggest it might inhibit the release of inflammatory substances from special cells called mast cells. The asthma drugs Intal (cromolyn) and Tilade (nedocromil) are believed to work in this way. However, there is significant direct evidence from human trials that Tilade and Intal taken by inhalation actually work. In contrast, no such evidence exists for quercetin taken in any manner; and it is highly unlikely that oral intake of quercetin could produce levels in the body similar to the levels used in those test tube studies.
Alternative medical literature frequently mentions
as a treatment for asthma. However, this idea seems to be based primarily on the use of intravenous magnesium as an emergency treatment for asthma. When you take something by mouth, it's a very different matter from having it injected into your veins. Studies of oral magnesium for asthma have shown more negative than positive results.
However, some evidence exists that intravenous or inhaled magnesium may be beneficial.
Preliminary evidence, far too weak to be relied upon at all, has been used to suggest that the supplement
coenzyme Q10 (CoQ
might be helpful for asthma.
Other natural products commonly recommended for asthma include the herbs
, as well as the supplements
is sometimes recommended as an herbal treatment for asthma; according to traditional directions, though, it should be taken to the point of vomiting—a process we can hardly recommend. None of these treatments have any meaningful supporting evidence.
, such as
are frequently recommended for asthma on the grounds that they may protect inflamed lung tissue. Although, one study found that asthmatics placed on a low antioxidant diet for 10 days experienced a worsening of their symptoms,
there is no direct scientific evidence at this time that antioxidant supplementation improves asthma. A rather theoretical study found evidence that use of vitamin E might decrease the inflammatory response in children with asthma exposed to ozone.
However, a far more meaningful double-blind, placebo-controlled study found vitamin E (as 500 mg of natural vitamin E)
Similarly, a large (almost 200-participant) study failed to find selenium helpful for asthma.
has been advocated as a treatment for asthma, based primarily on two studies conducted in the 1970s.
However, neither of these studies reached modern scientific standards. Two subsequent, and better designed, studies of picrorhiza failed to find the herb more effective than placebo.
One study failed to find a mixture of
(“friendly bacteria”) helpful for asthma in children.
But, another study found that a mixture of probiotic
and prebiotic galacto/fructo-oligosaccharide may help reduce wheezing in infants with eczema.
Children with asthma may have reduced growth, possibly due to use of inhaled steroids. One study failed to find protective benefits with a
The tested supplement did not contain calcium. Other studies have found that combination treatment with both
and vitamin D may protect bone density in people taking oral corticosteroids (for various reasons, including asthma).
Two exceedingly preliminary studies reported by one research group has led to publicized concerns that use of the insomnia supplement
may worsen night-time asthma.
However, one double-blind study of melatonin in people with asthma found evidence of improved sleep without worsening of asthma symptoms.
Other Alternative Therapies
, a form of "allergy shot" that involves drops under the tongue rather than injections, has shown promise for asthma.
Some people with asthma may also have
One way to discover if you are allergic to a certain food is through eliminating potentially allergenic foods from your diet, then systematically introducing them to see if a reaction occurs. This elimination diet should only be done under the care of your doctor because of the risk of severe allergic reaction. Other ways to diagnose a food allergy include the skin scratch test and blood tests (eg, RAST or ELISA). If you do have a food allergy, eliminating the offending food from your diet might reduce asthma symptoms.
A special breathing technique called Buteyko breathing may reduce medication use and subjective symptoms, though it does not appear to actually improve lung function.
and some other forms of
may offer modest benefits for asthma. The same is true of standard aerobic
In two controlled studies,
chiropractic spinal manipulation
has failed to prove more effective than fake manipulation for treatment of asthma.
One study of
reportedly found benefits, but its design was flawed.
Researchers have also studied factors that may prevent the development of
. For example, by examining two large groups of children—6,963 children aged 6-13 and 9,668 children aged 6-12, researchers determined that those living on traditional farms in a rural environments were exposed to a wider range of microorganisms and had fewer cases of asthma compared to those living in suburban environments.
These findings help to confirm what has long been known as the
, which states that exposure to a large variety of germs early in life tends to make the immune system less susceptible to allergic conditions later in life, such as asthma. This would help explain why asthma seems to become more common as societies became wealthier and less rural.