Melatonin Supplements May Worsen Asthma
People With Nocturnal Asthma Cautioned to Avoid Melatonin
Sept. 8, 2003 -- Treating jet lag or insomnia with melatonin supplements may actually make matters worse for people with asthma.
A new study suggests that melatonin supplements may make asthma
symptoms worse in people who already suffer from nocturnal asthma, or asthma
that naturally worsens at night.
Melatonin is a hormone produced by the brain that helps
regulate the body's circadian rhythms, or body clock. Levels of the hormone
peak at night, and this association with sleep has lead many to use melatonin
supplements as a remedy for jet lag or insomnia.
But melatonin has also been shown to increase inflammation of
the airways in animal studies, which can make it harder to breathe. That
prompted researchers to look at whether melatonin might play a role in
worsening nocturnal asthma symptoms.
Rise in Melatonin Linked to Nocturnal Asthma Symptoms
In the study, published in the Journal of Allergy and
Clinical Immunology, researchers followed seven people with nocturnal
asthma, 13 with non-nocturnal asthma, and 11 healthy individuals. After
establishing a normal sleep schedule for seven days, researchers took small
blood samples every two hours from the sleeping patients on the eighth night
and analyzed their melatonin levels.
The study showed that people with nocturnal asthma had the
highest levels of melatonin and the biggest decrease in lung function during
the night. Melatonin levels peaked at about 67.5 among nocturnal asthmatic
people, 61.1 in non-nocturnal asthmatic people, and 53.5 in healthy people.
"For patients whose asthma worsens at night, we found that
higher levels of naturally occurring melatonin are associated with impaired
lung function," says researcher Rand Sutherland, MD, MPH, of National
Jewish Medical & Research Center, in a news release.
"These findings suggest that melatonin naturally produced
by people with nocturnal asthma increases inflammation in their airways,
leading to worse lung function," says Sutherland. "Given that previous
work has shown that melatonin promotes inflammation in the cells of both
nocturnal and non-nocturnal asthmatics, any person with asthma should be
cautious about taking supplements that would further raise their melatonin