Hair dyes and cancer

Hair dyes have been linked to a variety of cancers including bladder cancer, breast cancer, leukaemias and lymphomas. But there is no clear evidence that hair dyes could cause any of these cancers. 

In 2008, the International Agency for Research into Cancer (IARC) said that hairdressers “probably” have a slightly higher risk of cancer because they are regularly exposed to certain chemicals. They can reduce their exposure to these chemicals by wearing gloves.

But there’s not enough evidence to say whether people who use hair dyes themselves have a higher risk of cancer as a result.
In the 1970s some hair dye ingredients were found to damage DNA and cause cancer in animals. But since then, the use of these chemicals has been discontinued and modern dyes are thought to be much safer. But cancer can take many years to develop – so it could be that the link we are seeing now between working as a hairdresser and cancer is because of exposures to these older chemicals many decades ago.

Hair dyes and bladder cancer

Results from studies linking hair dye to bladder cancer risk have been very inconsistent. Some studies have suggested that if a risk exists, it only applies to permanent hair dyes, rather than semi-permanent ones that wash out.

At the moment, there is not enough evidence to show that hair dyes affect bladder cancer risk. But we can’t completely rule out a risk either.

There is a theory for how hair dyes could increase bladder cancer risk. When we use hair dye, we absorb small amounts of chemicals called arylamines through our skin. Our bodies render these arylamines harmless and get rid of them through our urine. Along the way, they come into contact with the bladder.

Some people may inherit versions of the genes that control this process that are relatively poor at processing arylamines. As a result, these people may have an increased risk of bladder cancer if they use hair dyes regularly over a long period of time. But so far, this is just a possible theory and has not been conclusively proven.

Hair dye and other cancers

The evidence linking permanent hair dyes to breast cancer, leukaemias and lymphomas is very weak. Even if there is an increased risk, it would be very small.

Taking precautions

If you use hair dyes and are concerned about cancer, you could reduce your use or switch to lighter shades or semi-permanent types. These contain lower levels of chemicals than darker, permanent dyes.

In July 2006, the EU Commission announced that it would ban 22 different hair dye substances which do not have adequate safety files. This is a reassuring move for consumers as it means that only dyes that are proven to be safe will be available.

Smoking - putting risks in perspective

Smoking is the biggest risk factor for bladder cancer, causing over a third of UK cases. If you want to reduce your risk of bladder cancer, the best thing you can do is to not smoke. Tobacco smoke also contains arylamines.