What does the media say?
The media reported that passion fruit peel improves the symptoms of asthma.
What did the research show?
With 400 million global sufferers and limited effectiveness of drugs and lifestyle modifications, the teams from the US, Iran and New Zealand wanted to know if dietary changes might make a difference to asthma symptoms.
They explored the effects of bioflavonoids in passion fruit peel by randomising 43 asthmatics to placebo or peel in tablet form.
The patients took the treatment tablet (150mg or passion fruit peel extract) or placebo for four weeks. Clinical symptoms of asthma were assessed and spirometry tests were carried out.
100% of both groups had wheeze at trial start. At four weeks, only 19% of those in the treatment group had wheeze whilst 79% had in the placebo group still said they were suffering from it. Shortness of breath also went down – from 90% to 10% in the treatment group and from 79% to 37% in the control group.
Those in treatment group had an increase of 16% in forced vital capacity but there was no significant improvement in forced expiratory volume at 1 second (FEV1) However, in the placebo group there was a significant improvement in FEV1 compared to the baseline (up from 53% to 63%).
What did the researchers say?
The authors said: ‘As the extract has shown no toxicity in hypertensive rats and humans and now asthmatic patients, it holds promise to supplement or partially replace standard antiasthmatic drugs.
‘In addition, it could serve as an alternative therapy when readily available as a nutritional supplement. As many patients are not able to tolerate the currently available antiasthmatic medications, a natural dietary supplement with low or no toxicity would be an attractive candidate for further development.,’ they said.
What does this mean for nursing practice?
This study has a very small sample size and subjects were only followed up by four weeks, both of which limit its efficacy, as its authors acknowledge. Patients also had to self report their symptoms. All this limits the generalisability of the findings. Larger studies of longer duration are needed to validate it.
FEV1 is also one of the best measures of lung function and asthma symptoms and this actually improved in the placebo group not the treatment group.
‘While eating a healthy diet with plenty of fresh fruit and vegetables is to be encouraged for many reasons, and may be particularly beneficial for people with asthma, to date there is no conclusive evidence that this is a specific treatment for asthma,’ said Mike Thomas, chief medical adviser of Asthma UK.
‘This is a very small study on people with severe asthma who were not receiving their usual treatments, so the results should not be over-emphasised at this stage and by no stretch of the imagination can passion fruit peel extract be said to be a cure for asthma,’ he added.
Nutrition Research (2008) 28: 166-171