MYTH-BUSTING research is defining the skin health and comfort benefits of superfine Merino wool and the fibre parameters for wool growers hoping to supply the important therapeutic market sector.
Australian Wool Innovation said clinical studies are showing the therapeutic benefits of wearing superfine Merino wool for those suffering skin conditions such as eczema, also known as atopic dermatitis (AD).
Eczema typically results in itchy, red, cracked and painful skin. It often starts in childhood with an estimated 12-28 percent of children born in western countries affected. Separate clinical trials conducted by the Murdoch Childrens Research Institute and by the Queensland institute of Dermatology are challenging and breaking the significant myths that wool is not good to wear for those with AD and wool is a possible source of allergy, AWI said.
Program Manager of Fibre Advocacy and Eco Credentials with Australian Wool Innovation, Angus Ireland Angus Ireland said AWI was keen to develop a specification for wool that is suitable for sensitive skin.
“It is likely that that will evolve into a swing tag that brands would then put next to the Woolmark logo on their products.”
He said trials were conducted using light weight, 150 gram per square metre superfine Merino wool garments with a micron range finer than 18.6 microns, but there are a number of fibre, fabric and garment characteristics that affect the overall level of comfort of a wool garment.
Plenty of superfine wool for the therapeutic market
Mr Ireland said there was an abundance of superfine wool which doesn’t cause the problem of itchiness in garments.
“But it is not simply a matter of saying the wool has to be 18.5 microns or less because you can have a coarse edge in a wool lot, and that can be sufficient to cause itch.
“It is a number of short coarse fibres protruding from the fabric that causes the problem, so we’ve been anxious that the garments used in the studies don’t have them and we’ve been primarily using mean fibre diameter as well as the diameter distribution and also the wool comfort meter results.”
Mr Ireland said more research was needed and AWI did not believe all the important comfort characteristics of wool were measurable yet.
“We’re developing techniques to better measure the breathability of wool, for example; we think the current methods don’t really differentiate between fibre types, but I think we will come up with an interim specification and refine that over time.
“So what we’re saying at the moment is that it has to be superfine wool – by definition that’s 18.5 microns or less and you don’t want a coarse edge.”
The garments used in the studies all had a Laserscan comfort factor of more than 99pc, he said.
“The comfort factor is a measure of the proportion of fibres above 30 microns, but our more recent work is showing that a more sensitive reading is actually the proportion above 25 microns, so that’s likely to be in the specification.
“When it comes to the wool comfort meter results, these garments that we’ve been using have values of less than 400 (wcm),” Mr Ireland said.
“For Merino wool, if you’ve got 24 micron woven Merino wool you get a result of about 1300 and it you go down to ultrafine 15 micron wool it gets a wool comfort meter reading of about 100.”
Fabric weight, hauteur and yarn twist are important
Mr Ireland said the fabric weight of garments was important, with the research looking at a light weight garment – 150 gms per square metre — that could be worn all year round, he said.
Fibre length and processing also has a bearing on a garment’s next-to-skin comfort, with long stapled wool having less fibre ends.
“It’s the ends that cause the problem, not the length of the fibre, and itchiness is triggered by a certain number of short thick fibre fibres sticking out of the garment per square centimetre on the skin.
“So a longer hauteur in the top gives you less opportunity for ends, but the level of twist in the yarn can have a similar effect on the number of ends protruding – so it is more complex than just having a uniform fibre length distribution in your staple,” Mr Ireland said.
It is critical that consumers were able to buy correctly-specified wool garments that met their comfort needs, he said.
“It’s critical, because if some people read these studies and go out there and say Merino wool is the solution to my children’s problem and they get the wrong wool and put it on their kids and get an adverse reaction, you can undo years of research, overnight almost.”
Mr Ireland recognised that accurate raw wool comfort specifications were important to growers, but it was AWI’s intent to come up with garment tests so that brands or retailers who want to attach the ‘sensitive skin swing tag’ can test them against the specification.
“It’s only logical that that will follow back down the supply chain and growers will be able to look at what goes into those garments and know what they need to grow to produce the right product.”
Wool wearers experienced lower eczema severity
Mr Ireland said more than 65 adults and children have participated in the studies, across a range of climates and the garments have not only been tolerated by the eczema sufferers, but have helped improve the condition.
“This was achieved despite virtually all participants from the Brisbane-based study, with its hot and humid environment, reporting they couldn’t wear wool prior to the trial, yet none of them withdrew because of wool intolerance.”
The first paper entitled ‘Determining the Effects of Superfine Sheep wool in Infantile Eczema’ was presented at dermatology conferences in Australia, Brazil and France.
This study of children less than three years old employed a cross-over design where they wore superfine Merino wool for six weeks before changing over to cotton, and vice versa.
The researchers found when children switched over to wool after wearing cotton, they showed a significant decrease in eczema severity, whereas those who switched over to cotton after wearing wool showed worsening of eczema.
The study’s lead author, Associate Professor John Su from Monash University and Murdoch Childrens Research Institute, said the results “challenge our current practice” when advising about the suitability of wool for children with atopic dermatitis.
“When comparing with cotton, there are inherent differences in fibre properties, [Merino] wool’s greater ability to transfer moisture vapour and heat than other major apparel fibres enable it to maintain a more stable micro-climate between the skin and garment,” Associate Professor John Su said.
A mother of one of the children in the study, Rheannan Williams, said within two to three weeks of wearing wool it was “unbelievable”.
“Her skin is clear…I would 100pc recommend it, it’s amazing.”
The second paper, which specifically addresses the myth of wool allergy, will be submitted for publication next, followed by a third paper “An assessment of superfine Merino wool as therapeutic in the treatment of Atopic Dermatitis”.
The trials of the skin health benefits of superfine wool base layer garments for eczema sufferers have been under way for more than four years and have generated robust data supporting wool as therapeutic in the treatment of the condition, AWI said.
Three scientific papers associated with wool and skin health are being submitted for publication in high impact, peer-reviewed dermatological journals and are expected to be published by year’s end. A summary of findings are contained in a one-page review.