Passionfruit helps asthmatics

Passionfruit, a vine fruit which turns dark purple when ripe, may hold the key to help people who suffer from asthma to breathe easier. Scientists at Industrial Research Ltd (IRL) in New Zealand have been helping an American company to make a new type of medicine for asthmatics. The active ingredient for the medicine comes from passionfruit. The medicine has been tested on people who suffer from asthma in the United States with very positive results. The new medicine reduced the severity of wheezing and coughing among asthma patients and also helped to bring down blood pressure.

Forty-two people took part in the trial to test the extract made from purple passionfruit skins, they were randomly divided into two groups. One group received the extract, but the others did not. The patients did not know who was receiving the extract and who was receiving a placebo. Fewer than 20 per cent of people receiving the extract still had wheeze as a clinical symptom of asthma, compared to about 80 per cent of those in the control group. Moreover, coughing fell by 76 per cent in the extract group, compared to 47 per cent in the control group.

Another study done at the same time showed that the passionfruit treatment also significantly decreased blood pressure in those taking part in the trial.

The passionfruit breakthrough comes from collaboration between Professor Ronald Watson from the University of Arizona, and IRL natural products chemist Dr Lai Yeap Foo, which began with a chance meeting over lunch in 1999. The two men were seated next to each other during an international conference in France. Dr Foo had first identified the potential in passionfruit extract some years ago and has carried out extensive research to identify the compounds in it.

The trials were directed by Professor Watson, with IRL responsible for producing the extract. The findings, published earlier this year in the journal Nutrition Research, have caused a stir in the international medical and scientific communities.

“We now have two scientific publications indicating passionfruit has a beneficial effect on two very common but very different human diseases – hypertension and asthma – and that’s very exciting,” says Professor Watson.

The extract is now under license to an established nutraceutical company in the United States.

According to the US Centers for Disease Control (CDC), asthma affects over seven percent of the population in the US, or around 23 million people. Asthma is also on the rise in New Zealand, we have the second highest rate of asthma in the world (behind the United Kingdom), with some 600,000 people affected to varying degrees.

Despite the positive findings, the scientists note that the results were based on self-reporting of asthma symptoms, which may have recall errors. They also say that as only 42 subjects took part in this trial, it may not be accurate to generalise the results. No doubt more trials will go ahead in the future.