Millions are at risk of developing dandruff because of a little-known issue with their shower water, experts have warned.
The itchy condition, which causes white and yellow flakes to break out on the scalp, has been linked to areas with hard water – where large amounts of minerals are found in tap water.
About six in ten Britons live in affected areas, which occurs when water supplies pass through rocks containing high levels of calcium and magnesium, such as limestone and chalk. Soft water has low mineral content.
Despite being generally harmless, the minerals can create a build-up of limescale in kettles and drains – and may also cause dandruff, experts now claim.
‘Some people who live in a hard water area can experience itching and burning on their head, as well as a dry scalp, which can lead to flaky skin and aggravate dandruff,’ says Dr Aleksandar Godic, a consultant dermatologist based in London, which has some of the most mineral-rich water supplies in the country. ‘In my clinic I regularly see patients who have just moved to the area and, for the first time in their lives, are experiencing a dandruff flare-up.’
The East Midlands and the South East provide some of the hardest water in the UK and, as a result, have an increased risk of dandruff.
Data released this month reveals 71 per cent of people in London live with a flaky scalp.
By contrast, only a third of people in soft water areas, such as Scotland and Northern Ireland, are affected.
Hard water in parts of the country could be to blame for cases of dandruff
About half of all Britons will suffer from the condition at some point in their life.
It is predominantly triggered by a fungus named malassezia, which feeds on oil on the scalp and causes irritation when overproduced. And hard water – which some experts believe lessens the chance of developing dementia – is also thought to raise the odds of dandruff due to the mineral residue it leaves on the scalp, drying out skin and accelerating malassezia production.
To minimise the minerals’ effects, Dr Godic recommends installing a shower head filter. Some are available online for as little as £16.
And he suggests shampoos with chelating agents – ingredients that can strip the hair of hard water build-up. Also look out for those with Vitamin C, citric acid and ethylenediaminetetraacetic acid. Shampoos that contain chelating agents include Aveeno’s Clarify And Shine+ Apple Cider Vinegar Blend and the Hello Klean Full Length Anti-breakage Hard Water Shampoo.
But Dr Godic says many patients do not realise their hair care could be making the ailment worse.
‘A really common mistake is shampooing too often,’ he explains. ‘You should only be doing it twice a week, otherwise you will make your scalp drier again.’
And researchers warn that some dandruff cases may be a sign of psoriasis – a chronic skin condition which requires medical attention. It is typically managed with steroid creams and can also be caused by psoriatic arthritis, which leads to painful joints.
Dr Godic says: ‘If at-home remedies do not work or you are experiencing other symptoms such as joint pain, you should see a doctor.’
