Chemical Hair Treatments May Raise Women's Breast Cancer Risk

Posted by Sarah

In this article: Hair Loss | Women's Hair Loss


New research into women's risk of developing breast cancer has turned up some significant information, particularly for women of colour.

Findings from a seven-year study, published in the International Journal of Cancer, showed that regularly using permanent hair dye may raise a woman's risk of developing breast cancer to around 60 per cent.

Furthermore, chemical hair treatments used to straighten the hair were also found to considerably raise women's chances of getting breast cancer, with black women most harshly affected in each case.

Hair dyes, relaxers and Brazilian blow dry pose increased breast cancer risk

Relaxed hair coloured hair bleached hair dye afro hair straightened chemical straightener

A North Carolina-based team studied the association between hair products and breast cancer in 46,709 women. Each was aged between 35 and 74, and had a sister with breast cancer, but had no history of breast cancer themselves.

Through the use of questionnaires regarding hair product use over the 12 month period prior to enrolment, it was noted that 55 per cent of participants used hair dye when they started the trial.

At the follow up screenings, approximately 8.3 years after the study began, 2,794 cases of breast cancer were identified among those taking part.

Upon further investigation, researchers made the following associations:


  • an increased breast cancer risk of 45 per cent in black women who regularly use permanent hair dye;
  • an increased breast cancer risk of 7 per cent in white women who regularly use permanent hair dye;
  • risk of developing breast cancer rises with increased frequency of dye or straightener use;
  • an increased breast cancer risk of up to 60 per cent in black women who dye their hair at least every five to eight weeks;
  • chemical hair straightener (such as relaxers or Brazilian blow dry services) use linked to higher risks of developing breast cancer - particularly among black women whose use of such treatments was tallied at 75 per cent among participants, versus just 3 per cent of white women;
  • non-professional application of semi-permanent hair dye or chemical hair straightening products to another person linked to an increased risk of developing breast cancer.

In conclusion, the team stated, "We observed a higher breast cancer risk associated with any straightener use and personal use of permanent dye, especially among black women. These results suggest that chemicals in hair products may play a role in breast carcinogenesis".

The Guardian published an interesting piece about how breast cancer often hits black women harder, with affected women of colour being 40 per cent more likely to die from the disease than white women in America - the country where this new research was carried out.

Not only is this due to various socioeconomic factors, including many African American women's traditional 'need' to straighten their natural hair in order to conform to Western beauty standards - discrimination against Afro hair is known to be rife, and was only made illegal in some parts of America in late 2019 - but also due to the toxic chemicals numerous hair products aimed at black women have been found to contain.

Additional damage chemical hair treatments can cause

Whilst these figures make for sobering reading, there are a number of less physically impactful, but often emotionally draining adverse events connected to the use of chemical hair treatments.

Hair Cuticle Health - Damaged hair v healthy hair diagram - hair breakage

Use of chemical relaxers has been linked to endocrine disruption, as well as an increased risk of miscarriage for hairdressers who are regularly exposed to these products at close range.

Over-dyeing and over-bleaching can severely damage hair, causing breakage, where the weakened hair strands snap off. Relaxers, including keratin-based Brazilian blow drys, can also be responsible.

Harsh chemicals such as these, if the solution is too strong or they are left on for too long, may cause hair loss from a condition called Chemical Trauma. This is essentially burns to the scalp and, depending on how badly burned the follicles are, this can result in patches of permanent baldness in extreme cases.

Although the evidence is currently anecdotal, Belgravia often receives enquiries from people who have noticed thinning hair soon after having a Brazilian blow dry - a treatment designed to ensure a smoother, more longer-lasting blow out.

When it comes to hair straightening, whilst heat damage is also a consideration, occasional use of flat irons or a roller brush blow dry are preferable to chemical straightening. Just be careful to use a heat protector product first, to help disperse the heat more evenly, and not to pull too hard when using a brush, as repeated blow-drying which harshly pulls at the hair may cause Traction Alopecia in any hair type. For Afro textured hair, a chemical- and heat-free technique known as African Threading is a great alternative.

For those who still wish to use such hair products, the best advice is to consult a professional and experienced stylist who can properly mix and apply these for you. For those using home-use kits, it is crucial to always follow the instructions to the letter, and if you are in any doubt or have any queries regarding the application process, always contact the brand or retailer for answers first.

Perhaps the most important point in both cases, whether you are getting your hair done at a salon or doing it yourself, is to carry out a patch test at least 48 hours in advance. This is key even if you have used the same product before as intolerances can build up so you may react differently, even to the same product, at different times.


Copy of New Street Ground Floor Reception 1 no pink nail polish

The Belgravia Centre

The Belgravia Centre is a world-renowned group of a hair loss clinic in Central London, UK. If you are worried about hair loss you can arrange a free consultation with a hair loss expert or complete our Online Consultation from anywhere in the world for home-use treatment.

View our Hair Loss Success Stories, which includes the world's largest gallery of hair growth photos and demonstrates the level of success that so many of Belgravia's patients achieve.

Posted by Sarah

In this article: Hair Loss | Women's Hair Loss


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