A flavonoid-rich extract from
purple passion fruit may ease wheezing amongst asthmatics,
suggest findings from a randomised, placebo-controlled,
double-blind trial.
Fewer than 20 per cent of the subjects receiving the
passion fruit peel (PFP) extract still had wheeze as a
clinical symptom of asthma, compared to about 80 per cent
of subjects in the placebo group, according to findings
published in the journal Nutrition Research.
Moreover, coughing fell by 76 per cent in the extract
group, compared to 47 per cent in the placebo group, said
the researchers, led by Ronald Ross Watson from Southwest
Scientific Editing and Consulting, and Enid Zuckerman
Arizona College of Public Health in Tucson, Arizona.
"The results of the present study demonstrated the
clinical benefit of daily oral administration of PFP in
adults with persistent asthma, with safe use," stated the
researchers.
"As many patients are not able to tolerate the currently
available anti-asthmatic medications, a natural dietary
supplement with low or no toxicity would be an attractive
candidate for further development."
According to the European Federation of Allergy and Airway
Diseases Patients Association (EFA), over 30m Europeans
suffer from asthma, costing Europe €17.7bn every year. The
cost due to lost productivity is estimated to be around
€9.8bn.
The condition is on the rise in the Western world and the
most common long-term condition in the UK.
Promising results
Watson and co-workers recruited 42 asthmatics with an
average age of 36.1 and randomly assigned them to receive
a daily passion fruit peel extract (150 mg per day) or
placebo for four weeks.
At the end of the study, the researchers report that the
majority of clinical asthma symptoms were "moderately"
affected. Specifically, they note "the prevalence of
wheeze, cough, as well as shortness of breath was reduced
significantly in group treated with PFP extract whereas
the placebo caused no significant improvement."
Coughing was reduced by 76.2 per cent, wheezing by 80.9
per cent, while the number of people experiencing
shortness of breath was reduced from 90 per cent at the
start of the study to only 10 per cent at the end,
following four weeks of the passion fruit peel extract
supplements.
On the other hand, no significant improvements were
recorded with respect to lung function, with no changes
measured in the forced expiratory volume at 1 second
(FEV1) in either group.
From a safety perspective, Watson and co-workers report
none of the study participants reported any adverse
effects.
"The results of this clinical study indicate that the PFP
extract may be a valuable nutriceutical [sic] supplement
in the management of chronic asthma," wrote the
researchers.
Mechanism of action
Several potential mechanisms of action were proposed by
the researchers. Firstly, they suggested a role for the
antioxidants in the peel extract, noting that many studies
have reported a link between "oxidative stress, bronchial
inflammation, the development of asthmatic symptoms, and
reduction of cellular functions".
"Therefore, a role for antioxidants in reducing pathology
is likely, particularly during exacerbation of asthma,"
they stated.
A second potential mechanism could involve the role of the
flavonoids in reducing allergy and inflammation.
"[Flavonoids] can inhibit histamine release, arachidonic
acid metabolism, and cytokine production," they added.
The article notes that a patent is pending for the passion
fruit peel extract.
Study limitations
Despite the positive findings, the Watson and co-workers
note that the results were based on self-reporting of
asthma symptoms, which may be subject to recall errors,
while they also note that only 42 subjects took part,
which may prevent the results being generalised. The short
period of the study was also noted as a limitation.
The researchers were affiliated with Southwest Scientific
Editing and Consulting in Tucson, Arizona, Mel and Enid
Zuckerman Arizona College of Public Health in Tucson,
Arizona, Mashhad University of Medical Sciences in Iran,
Integrated Bioactives Technologies (Industrial Research
Ltd) in New Zealand
Source: Nutrition Research (Elsevier)
March 2008, Volume 28, Issue 3, Pages 166-171
"Oral administration of the purple passion fruit peel
extract reduces wheeze and cough and improves shortness of
breath in adults with asthma"
Authors: Ronald Ross Watson, S. Zibadi, H. Rafatpanah, F.
Jabbari, R. Ghasemi, J. Ghafari, H. Afrasiabi, L.Y. Foo,
R. Faridhosseini |
