Does hair dye increase cancer risk?

Colouring your hair more than nine times a year has been linked to various health scares.

Blame it on the quest for eternal youth or everchanging celebrity hair-dos but, the fact is more of us are dyeing our hair than ever.

Most people colour their hair between six and eight times a year, either at home or at the hairdresser.

Cancer

If you dye your hair more than nine times a year you could be 60 per cent more likely to develop a form of blood cancer called chronic lymphocytic leukaemia, a new study claims.

And using dark hair dyes could increase your chances of developing follicular lymphoma, a form of non-Hodgkins lymphoma, by 50 per cent, according to the American Journal of Epidemiology.

But the researchers say a higher risk was mainly seen in women who started using hair dyes before 1980, when they contained more toxic chemicals than they do now.

Another recent study found hairdressers and barbers have an increased risk of bladder cancer, which is thought to be caused by daily exposure to the chemicals in hair dye.

Allergy

Figures state three in every million people have an allergy to hair dye, but the real number may be far greater. Researchers writing in the British Medical Journal suggest the number of allergic reactions to hair dye has doubled in the past few years.

Reactions can vary from a slight tingling sensation to an itchy, red and swollen scalp, face and ears, a condition known as allergic contact dermatitis. And, although it's incredibly rare, severe allergic reactions called anaphylaxis can kill.

People with sensitive skin or other allergies may be more susceptible to hair-dye allergy, says trichologist Jane Mayhead. "And if you've been on a diet or under extreme stress, or if you've just been ill, your immune system may be weakened, and that could make you react too," she says.

The most important safeguard against an allergic reaction to hair dye is to carry out a skin-patch sensitivity test 48 hours before you colour your hair and, most importantly, do the skin test every time you use hair dye, even if you're using a product you've used safely for years.

Miscarriage

Reports that hair dye may be linked to miscarriage were sparked by a Dutch study that compared pregnancy problems among hairdressers and clothing salespeople. The study found that hairdressers had a slightly higher risk of miscarriage but by the researchers' own admission, the numbers were very small.

"Even though some studies show that people who work with hair dyes have a slightly increased risk for miscarriage, the results are based on information that goes back years when hair dye was much more toxic than it is now," explains Annette.

Hair dye dos and don'ts

Most experts agree that hair dyes are safe, but there's no 100-per-cent guarantee they're completely risk-free. Here's how to do it safely:

Do use a semi-permanent dye rather than a permanent one. Semi-permanents are in contact with your scalp for less time, so your skin absorbs fewer chemicals.

Don't skip the skin patch sensitivity test, even when using a dye you've used before. "A patch test is a must," says Marc Ramos, colour consultant for Naturtint. "Read all the instructions properly beforehand, and always wear rubber gloves."

Do have highlights or lowlights at the hairdressers, as the dye doesn't come into contact with your scalp. Many hairdressers also offer safer, vegetable-based hair colours.

Don't use hair dyes too frequently, as regular use may increase potential health risks. Make the colour last longer by using special shampoos and conditioners for coloured hair.

Do switch to a lighter hair colour, as these contain smaller concentrations of PPD.