Flower power helps fight off colds
29 June 2007
Scientists have shown that taking echinacea can halve your chances of catching a cold and cut recovery time by more than a day. But will the evidence convince herbal-remedy sceptics?
Antenna investigates...
An echinacea plant growing wild.
Image: Stock.XCHNG/dria peterson
We've all woken up bunged up and bleary eyed after catching a cold. And while some of us swear by paracetamol, many people turn to herbal remedies. One of the most popular is echinacea, which its fans say boosts the body's immune system, helping ward off snot and sneezes.
The average adult gets around four colds a year and kids can catch as many as ten in that time.
So could a wild flower really keep sniffles at bay? Now US scientists have new proof. They've been weeding out the fact from the folklore in the biggest echinacea study yet.
There are nine different species of Echinacea plants, all native to North America. But only three are thought to have cold-fighting capabilities.
Image: Stock.XCHNG/Gillian Townsend
What did they do?
The team combined the results of 14 previous echinacea trials into one mega-study in order to get much larger patient numbers. By adding up all this evidence they could get to the root of whether echinacea really works.
Echinacea supplements can be made from all different parts of the plant but experts aren't sure which bits really work best.
Lead researcher Craig Coleman explains: 'Getting a larger study group was really important. If you look at previous echinacea studies many of them show positive results, but the study groups just weren't large enough to prove the effects.
'When we combined these trials we had as many as 1600 people in some of them - enough to detect effects that smaller studies are unable to show on their own.'
Craig Coleman, University of Connecticut School of Pharmacy, USA.
Herbal remedies...
They found that taking echinacea supplements before the onset of a cold reduced the chance of catching it by more than half. If patients took the remedy at the first signs of symptoms it could cut the suffering time by over a day.
More than 200 different viruses like this can cause cold symptoms. That's why we're so susceptible to catching them.
Image: CDC/Craig Lyerla
Craig thinks these results could be good news for some cold sufferers. 'If you take echinacea supplements over the winter months or in high-risk environments such as on planes it could really help reduce your chance of catching a cold. But I wouldn't recommend taking it on a daily basis all through the year.
'Although it's generally regarded as safe there haven't been any large trials to test the long-term safety of echinacea. Plus patients with autoimmune diseases shouldn't take it, or those on certain types of medication, as it may stop other drugs from working effectively.'
Cold expert Ron Eccles is also impressed, but has a warning too: 'There is increasing evidence that it is doing something positive to the immune system,' he says. 'But I think the biggest issue for the general public is, "what sort of echinacea do they use?" At the moment there is no way of standardising this product.'
'The big problem with echinacea is that we don't know exactly what's causing this effect - we need to work out the active ingredient, although we may find it's a whole soup of compounds working together and extracting just one won't work.'
Ron Eccles, Director of the Common Cold Centre, Cardiff University.
Image: Cardiff University
'What I would like to see is a single large-scale clinical trial that really shows the effect. This is an area well worth looking into, as we may stumble across something that's very effective.'
Craig agrees. 'It can be difficult to get support for these types of studies. We're hoping our study will make people start to think about the potential of echinacea and inspire them to do the studies that need to be done in order to answer many of these questions.'
