Parabens: a witch hunt

Author: Yulia Gagarina , chemical technologist, cosmetologist, leading specialist in the development of new products at Ecolife (Kiev)

The wrong side of cosmetics

Like everything in this world, cosmetics have side effects. For example, it can potentially cause allergies. Thus, in a report by Spanish doctors regarding cases of contact dermatitis due to cosmetics (research was carried out in Valencia, at the General Universitario de Valencia hospital from 2000 to 2007), a list of cosmetic products that most often cause allergies is given:

• hair dyes – 18.5%;
• gels/soaps – 15.7%;
• moisturizers – 12.7%.

The sample included 2,485 patients. The study identified reactions to 46 potential cosmetic allergens. A “black list” was formed of the most powerful allergens:

• methylisothiazolinone (methylisothiazolinone, a preservative, gives an aggressive reaction if used independently) – 19%;
• paraphenylenediamine (paraphenylenediamine, dye, used to obtain black color in hair dyes) – 15.2%;
• individual components of fragrances – 7.8%.

It is not surprising that after summarizing the data from this and similar studies, preservatives immediately become “suspect No. 1” when it comes to the idea of a skin reaction to a cosmetic product.

Preservatives: list of suspects

Recent work by Polish researchers has stated a sad fact: the number of allergy sufferers is steadily growing, and they are increasingly reacting to those preservatives that were previously safe for them. This suggests that any person, having reached a certain age, can wake up one day with a “blooming face” only because his immune system recognized too aggressive “strangers” in the face cream. That is why various groups of preservatives are under close supervision. As soon as data appears about the unsafety of a product, legislative bodies in different countries review their requirements for them.

In the work of Polish scientists, data from 113 patients who were allergic to the following preservatives were analyzed:

• thimerosal (used both in decorative cosmetics and in vaccines) – 11.8%;
• formaldehyde – 4.9%;
• Euxyl K 400 (a mixture of two preservatives – Methyldibromo Glutaronitrile + Phenoxyethanol) – 3.7%.

The group of quaterniums and parabens had the lowest rates - 0.8 and 0.3%, respectively.

In 2005, the European Scientific Committee for Consumer Safety (SCCS) published a report that banned the use of the preservative Methyldibromo Glutaronitrile in cosmetic products. Now its scope of application is limited to wash-off products: household chemicals, auto chemicals and veterinary drugs (for example, animal shampoos).

A little later, the world community was literally overwhelmed by a discussion about the safety of another group of preservatives - parabens. The piquancy of the situation lies in the fact that short-chain parabens (methyl-, propyl- and ethylparabens) have always been considered one of the safest. That is why the discussion turned out to be especially heated.

Parabens in cosmetics and medicines

Parabens are widely used not only in cosmetics, but also in pharmaceuticals and the food industry. We eat them in such large quantities that industry produces millions of tons of them per year. And all because, with high efficiency, they are low cost and almost do not cause allergic reactions. Therefore, they are still considered the best choice for baby care cosmetics.

Short-chain parabens (for example, methyl and propylparaben) have long been included in syrups, tablets and other dosage forms for internal use. There they showed themselves exclusively from the best side: they are easily absorbed, digested and excreted from the body without visible side effects. However, if you set out to find parabens in medicines, you should take into account that they appear there in a slightly different spelling: methylparaben is methyl parahydroxybenzoate (E218), propylparaben is propyl parahydroxybenzoate (E216).

"Witch-hunt"

Let's return to the starting position - to 2007. Parabens have an excellent reputation and a seemingly bright future. But an article by English researcher Philippa Darbre comes out about a possible connection between antiperspirants containing parabens and breast cancer. She and her colleagues were prompted to do this by the fact that in approximately 60% of cases, the tumors analyzed in the upper outer quadrant, closer to the armpits, contained parabens. After this material, only the lazy did not learn the words “preservatives and parabens”. Fortunately, the words are easy to remember and easy to find with your eyes on the label (compare with the difficult to pronounce “methyldibromoglutaronitrile”, which was described above).

Safety potential

The accusations against parabens were serious, so it became impossible to dismiss the potential danger. Therefore, taking these concerns into account, the FDA (in the USA) and SCCS (in Europe) organized a re-examination of the safety of the following group of parabens: Methylparaben, Ethylparaben, Isopropylparaben, Butylparaben, Isobutylparaben and Benzylparaben.

On 22 March 2011, the European Scientific Committee for Consumer Safety (SCCS) published a report that includes data from recent research from 2009–2010. Their verdict is:

• in cosmetics, the use of parabens is allowed at a concentration of 0.4% for one paraben and at a concentration of 0.8% for a mixture of parabens;
• According to the current evidence, there is no evidence of an obvious risk of breast cancer caused by the use of cosmetics in the armpit area;
• the use of methylparaben and ethylparaben is not of concern, but at the same time, SCCP believes that there is insufficient data to assess the safety of propyl and butylparaben and research on these components should continue; however, their use is currently considered safe within the indicated dosages.

Portrait of parabens in detail

The same SCCS report summarizes the data available to date to provide the following characterization of this type of preservative.

Penetration and accumulation . Butylparaben is able to penetrate the stratum corneum of the skin, but does not have the ability to significantly change skin metabolism and affect hormonal levels. Also, parabens do not accumulate in the human body. Even if injected intravenously, their amount in the blood plasma decreases sharply.

Toxicity . Chronic oral toxicity tests show that parabens are essentially non-toxic.

Mutagenicity. Numerous genotoxicity studies indicate that parabens are not mutagenic. That is, under their influence, cells (including cancer cells) do not begin to degenerate.

Estrogen-like action . Two studies suggest that isobutylparaben has properties similar to estrogens, but is at least 240,000 times less potent than estradiol (a natural female hormone). One study found that benzylparaben also has estrogenic activity that is at least 330,000 times less than estradiol. The estrogenic activity of these parabens resulted in increased growth of breast cancer cells in cell culture (in vitro), but the growth was approximately 3 to 6 orders of magnitude less than that of estradiol.

Sensitization and allergy . Parabens are practically not sensitized in people with normal skin. Although a case of allergy to parabens has been documented in the literature, this was due to contact with damaged skin. When patients with chronic dermatitis are patch tested with parabens, a reaction occurs in less than 4% of subjects. Clinical observations over the past 20 years have not recorded changes in the reaction of patients’ skin to parabens (there are no negative dynamics, generations of people do not get used to parabens, it has not become an allergen for us).

Paraben- free: does it make sense?

While the scientific community was fiercely fighting over the safety of parabens, cosmetics manufacturers reacted with lightning speed. Drugs labeled “paraben-free” began to appear on the market. The demand for “green”, natural types of preservatives has intensified. By the way, an interesting point: p-hydroxy-benzoic acid, from which parabens are obtained, is present in plants, including berries (acai, lingonberry, etc.), so we can say (albeit with some stretch) that methyl and ethylparaben are “almost natural” preservatives.

There is also a growing demand for substances with antimicrobial effects, which in fact may not even be traditional preservatives. After all, then you can write an even more attractive thing on the label - “no preservatives!” How justified is this? From a marketing and sales point of view, this is not even a question. But from the point of view of dermatology, there is reason for discussion. In the book “New Cosmetology,” edited by E. Hernandez and A. Margolina, the following idea is expressed: “Contrary to popular belief, children's cosmetics should not be free from preservatives, since microbial contamination of the product is much more dangerous than the preservatives themselves. Moreover, substances used as an alternative to preservatives (essential oils, alcohol) are much more likely to cause allergic reactions or skin irritation than well-chosen preservatives.” It's hard to disagree with this opinion.

Instead of a conclusion

In a recent publication, paraben storm mastermind F. Darbre noted that their study was preliminary because it was based on a small sample of patients. Parabens were detected in tissue samples at the nanogram level (that is, critically small doses), while the researchers did not receive reliable confirmation that parabens entered the body from cosmetics and not from other sources.

A group of scientists summarized the data on the topic “Parabens as provocateurs of breast cancer” and came to the following conclusion: “There is no scientific evidence to support the hypotheses put forward and, apparently, there are no hypotheses that could open a way in the area of research of interest. Ultimately, it can be argued that this issue does not constitute a public health problem and therefore it is futile to engage in research on this topic.”

Source: Les Nouvelles Esthetiques Ukraine, No. 3 (67), 2011, pp. 98-100