A cure for dandruff?
For those of us blessed with a reasonable head of hair, one of the problems we can encounter is dandruff, those scaly bits of loose skin which descend from our scalp when we comb our hair and settle like snow on our collar. I use an anti-dandruff shampoo which boasts a HydraZinc formula which, reassuringly, suggests the user can look forward to up to 100% removal of visible flakes. It always does to set the bar of expectation fairly low, I suppose.
Whilst scientists can split the atom, their understanding of what causes dandruff and what can be done to prevent it is not as advanced as you may think. Perhaps that is why they wear white coats. But our understanding of dandruff may have moved forward apace if some research conducted by a team led by Menghui Zhang at Shanghai Jiao Tong University and published in the ever popular Scientific Reports is to be believed.
Zhang invited into his lab 59 volunteers aged between 18 and 60, all of whom had washed their hair to days before, and gathered dandruff from eight different areas of their heads. He then divided them into healthy and dandruff groups, depending upon how much visible flaky skin he could detect.
Up until now it has been thought that a group of fungi called Malassezia was the principal cause of dandruff, attacking the sebum produced by the sebaceous glands on our scalp, producing oleic acid, which in turn irritates the skin and causes flakes to appear. My anti-dandruff shampoo’s revolutionary formula is based on attacking this dandruff causing fungi. But Zhang found Malassezia fungi on the scalps of those who were dandruff-free as well as on those who could create a snow storm of their own accord.
Zhang switched his attention to the bacteria living on our noddles, Propionibacterium and Staphylococcus. He noted that on the healthy heads with little or no dandruff, Propionibacterium made up 71% of the scalp bacteria and Staphylococcus 26% but on the heads of those with dandruff Propionibacterium made up just 50% of scalp bacteria whilst Staphylococcus accounted for 44%.
These two forms of bacteria compete with each other and where Staphylococcus starts to get the upper hand, dandruff is more likely to appear. Scalp sebum is a particularly good source of food for Propionibacterium. Interestingly, Zhang found that sebum secretions peak between the ages of 15 and 35 and then tail off whilst those over 40 had more severe dandruff than their younger counterparts. So it may just be that the way to control dandruff on the scalp is to encourage the good bacteria and suppress the bad bacteria.
But how can that be done? Frustratingly, this is the next area for Zhang to look into but one approach may provide an environment in which Propionibacterium could be nurtured. At the very least this may well mean some revolutionary new anti-dandruff shampoos.
One source may just be yoghurts that contain the good bacteria. In 2013 scientists discovered that a yoghurt laced with Propionibacterium could help protect the skin from the hospital super-bug, Staphylococcus aureus. Perhaps in a few years’ time we will be massaging yoghurt into our scalps rather than the current so-called anti-dandruff shampoos which, if Zhang is right, may not be as effective as they claim to be.
So now we know!