Is there really a relationship between hair straightening and uterine cancer?

An American scientific study has just established a relationship between hair straightening and uterine cancer. The alarms have gone off and the media have echoed this work.

On October 22 of this year, a study by the National Institute of Health of the United States Department of Health revealed in the Journal of the National Cancer Institute that hair products may contain dangerous chemicals with carcinogenic and endocrine-disrupting properties. These disruptors (a very fashionable word) are a series of chemical substances capable of altering the hormonal system of the human organism and generating its dysfunction.

Other studies had already associated an increased risk of cancer, both breast and ovaries, but nothing had ever been stated about the uterus. For this reason, the news has spread like wildfire.

The Internet search for “smoothing and uterine cancer” shows a figure close to 2,000 million results. That is, people -and especially us women- are concerned about whether there is a relationship between straightening and uterine cancer. We explain below that the products used in Spain and the European Union are free of chemicals that could cause this disease.

Let’s start from the basis that everything in this world is chemistry; down to the water. That does not mean that everything that falls into our hair or on our face is going to give us cancer.

Fortunately for us, in Europe and therefore in Spain , there is a very restrictive law regarding potentially dangerous substances. Having established this premise, the scientific work, called the Sister Study , was carried out in a population of 50,884 women between the ages of 35 and 74 who did not suffer from disease in utero between 2003 and 2009, but who did have or had had a sister. with breast cancer.

Evidence of association between hair straightening and uterine cancer

During a period of 10.9 years, 262 cases of uterine cancer were identified . The ever use of smoothing products was associated with higher rates of uterine cancer. However, the use of other hair products, including dyes and perms, did not bind this type of tumor. Of course, in the survey addressed to each member of the program, they were asked if they had used hair products in the last 12 months.

The uterine cancer findings are the first epidemiological evidence of an association between the use of hair straightening products and uterine cancer. The United States Department of Health will continue to investigate to replicate its findings in other settings.

Some of the substances that would be behind these cancers, which are more associated with black people because they are the ones that use the most straightening products, are parabens, bisphenol and formaldehyde.

Do we use these products in Spain?

Do not cry to heaven because these products are not allowed in Spain . Parabens are a group of ingredients that are used as preservatives. They are very useful to avoid contamination by bacteria, fungi or yeasts, which is why they serve to guarantee the safety of cosmetic products and extend their useful life.

But the family of parabens is very wide, and very few are used in cosmetics. A few years ago, some studies linked the presence of parabens with health problems such as breast cancer or male infertility. However, subsequent research found that there was no direct relationship between parabens and health problems. Still, the European Union banned the use of 5 parabens. The claim “without parabens” is almost a strategy of some brands to differentiate themselves from others that do not. And, since it is a preservative, if the cream in question does not contain parabens, it will have to have been formulated with another preservative.

It is a lure just like the “cruelty free” one . In Europe , testing with live animals has been prohibited since 2013 ; It is thus another claim by the industry to distinguish itself from cosmetic companies that do not use the label on the packaging.

Bisphenol is another chemical product that has been used for many years as a component for the manufacture of polycarbonate and epoxy-phenolic resins and that enter into the composition of containers.

As I explained to you, European legislation is very demanding and they have also provided their data. The European Food Safety Authority (EFSA) has worked in recent years to reassess the potential risks of bisphenol. As a result of these works, the scientific opinion that considers that this substance is safe has recently been published .

And are formaldehydes responsible for the relationship between hair straightening and uterine cancer?

Formaldehyde is a colorless, strong – smelling, flammable chemical that is used for some industrial uses and in the healthcare sector to perform some very specific types of tests.

To answer this question, we are going to know the opinion of Maria Jose Tous, pharmacist, cosmetologist and founder of the Kosei brand. “It is a mistake to extrapolate the results obtained in the United States because Spanish legislation does not allow the use of straighteners with formaldehyde.”

For Maria Jose Tous , “the article that mentions the relationship between hair straightening and uterine cancer does not take into account that there are many types of straightening with different types of ingredients. From my point of view, you should have said that you were referring to formaldehyde-based smoothing treatments, and not generically to straightening treatments. We already know that formaldehyde is a carcinogenic agent and in fact, it is banned in most countries in the world, not just in Europe . “

What compounds are hair straighteners made with in Spain?

The answer is complex because the ingredients with which smoothing is made in Europe/Spain are varied; there is no single ingredient that can perform this function.

Maria Jose Tous explains to Belleza Pura that “The oldest are thioglycollates -used for both curling and straightening hair-, and they are the ones that were used in the era of perms. It is difficult to control the end point of the treatment and they damage the hair a lot. The most modern are made from glyoxylic acid or its salt, glyoxylate, carbocysteine ​​or derivatives, and cysteine ​​derivatives. The key is in the percentages of each of these ingredients, their combinations and the base (emulsion ingredients) in which they are formulated. All of this is what will give the form of application (whether it is appropriate to wash after applying the treatment to the hair, before ironing the hair or not). And everything mentioned above affects the result in terms of hair straightening and how the hair fiber is left (more or less damaged)”.

If we go to the legal field there is also information to provide. “Any cosmetic manufactured in Europe must have a dossier called PIF (Product File Information) in which a technician (pharmacist, doctor, specialized chemist) must carry out a safety assessment based on the toxicological profile of the substances that form part of the finished product, its way of use, the place and the amount of application” , explains the creator of Kosei.

“For this reason – concludes Maria Jose Tou s -, people who get straightening should not be afraid in this sense. As long as they are using a product whose origin and composition are known”.

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