Kemri researchers link hair relaxers to brain cancer
Women who use chemical hair relaxers may have a higher risk of brain cancer, according to a new study from researchers.
What you need to know:
- The Kemri study is linked to another conducted in the United States and Ghana, which found evidence that the use of certain personal care products (PCPs) and hair products, such as permanent hair dyes and chemical relaxers, increased the risk of breast cancer.
Researchers at the Kenya Medical Research Institute (Kemri) have discovered formaldehyde, a harmful neurotoxin that can cause brain cancer and impair memory, in hair relaxers widely used in the country.
Kemri's toxicology report shows that at least eight hair relaxers are affected. However, the researchers did not name the brands in the report.
"Six (75 per cent) were manufactured in Kenya and two (25 per cent) in Uganda and South Africa respectively. Five (62.5 per cent) were labelled 'for professional use only'," the Kemri study said.
Some 11 different chemicals of concern (COCs) were identified in the eight hair relaxers.
In particular, petrolatum and sodium hydroxide (Tier 2) were present in 100 per cent and 87.5 per cent of the relaxer products, while relaxers from the same manufacturer contained both formaldehyde and isoeugenol (Tier 1).
The investigation focused on Embu County and was prompted by an increase in cancer cases there.
However, the brands tested are widely used in other parts of the country, particularly in Nairobi.
The Kemri study is linked to another conducted in the United States and Ghana, which found evidence that the use of certain personal care products (PCPs) and hair products, such as permanent hair dyes and chemical relaxers, increased the risk of breast cancer.
"A total of 366 women aged 15-50 years consented to and were enrolled in a questionnaire-based study that assessed participants' sociodemographic characteristics, use of hair products and other PCPs for 7-14 days, and use of hair dyes and chemical relaxers," they said.
They then purchased eight hair relaxers, reviewed the information on the labels, and recorded the strength of the relaxer, the list of ingredients, the manufacturer and location, and other label claims.
"We then compared the list of ingredients with the Campaign for Safe Cosmetics' Red List - a list of chemicals of concern (COCs) in cosmetics and personal care products (PCPs) - to assess the frequency and proportion of COCs (out of the total number of ingredients) listed in each product," they explained.
The researchers concluded: "Our analysis documented relaxants containing CoCs that should not be used in PCPs."
This is why they are concerned and believe that a review of the regulatory framework for PCPs in relation to PCPs and cancer risk is urgently needed.
Secondly, they say there is a need to educate the public about the chemical composition of PCPs and their likely adverse health effects.
"Such awareness will help consumers make informed choices when purchasing and using these products. Our future work will include analysing CoCs in other PCPs available on the Kenyan market and assessing the regulatory requirements for hair relaxers in Kenya," the Kemri scientists concluded.
According to the Campaign for Safe Cosmetics (CSC), formaldehyde and formaldehyde-releasing preservatives (FRPs) are used in many personal care products, particularly shampoos and liquid baby soaps.
These chemicals, which help prevent the growth of microbes in water-based products, can be absorbed through the skin and have been linked to cancer and allergic skin reactions.
The CSC points out that formaldehyde is a colourless, strong-smelling gas used in a wide range of industries and products, including building materials, walls, cabinets, furniture and personal care products.
The United States National Toxicology Programme and the International Agency for Research on Cancer highlight a literature review on occupational exposures and formaldehyde that shows a link between formaldehyde and leukaemia.
"A 2014 study found that formaldehyde initiates and promotes tumour formation. When formaldehyde is present in personal care products, people can be exposed through inhalation, ingestion or absorption through the skin," they note.
For this reason, CSC has developed a 'Red List' of chemicals of concern in cosmetics to serve as a resource and tool to help brands, companies and retailers reduce their use of toxic chemicals in the beauty and personal care products they make and sell.
The Red List categorises COCs into three tiers (based on authoritative lists including the International Agency for Research on Cancer and the US National Toxicology Program). "Tier 1, COCs that should be banned from use; Tier 2, COCs that are emerging and harmful to the environment; and Tier 3, COCs classified as asthmagens, allergens and irritants that should be avoided in PCPs whenever possible," they explain. According to the CSC, a review of 8,119 titles and 580 scientific papers has revealed a bias in scientific research on chemical exposures.
"The research does not take into account the disproportionate burden that black women face from the use of beauty products," says CSC.
"There is also inadequate coverage of hazardous chemicals associated with adverse health outcomes in Black women by government and scientific organisations that produce authoritative lists of hazardous chemicals," they point out.
"Our goal was to identify and better understand the chemicals in beauty and personal care products that negatively impact the health of black women in order to address their unique health concerns."
Currently, Japan and Sweden have completely banned the use of formaldehyde in cosmetics and toiletries, while the European Union (EU) restricts it to personal care products and requires labelling of products containing these chemicals.
Canada has concentration limits, while the EU allows the use of quaternium-15 as a preservative in cosmetic products up to 0.2 percent.
