Parabens in cosmetics: a risk to our health?

What are parabens?
“Paraben” is a common name for parahydroxybenzoates or esters of parahydroxybenzoic acid that are widely used as preservatives in cosmetic, pharmaceutical and food industry 22. The parabens effectively prevent growth of bacteria and fungi in many types of products 6.
The most common parabens are:

- Methylparaben (E218)*
- Ethylparaben (E214)
- Propylparaben (E216)
- Heptylparaben (E209)
- Butylparaben
* codes for substances used as food additives

Where are parabens used?
Parabens have been used as preservatives for more than 50 years 11. Processed vegetables, seasonings, sugar substitutes, pickles, sauces, soft drinks, syrups and jams is just a short list of products often containing parabens 22. These chemicals have also been employed in many pharmaceutical preparations such as pills, suppositories, anesthetics and contraceptives 22.
Parabens are also widely used in cosmetics in different product categories:
- Shampoos and conditioners
- Body lotions
- Shower gels
- Scrubs
- Sunscreen cosmetics
- Deodorants and antiperspirants
- Moisturizers
...

Parabens in nature
Interestingly, parabens are also present in nature (e.g. blueberries, cloudberry, yellow passion fruit) 1, but at very low concentrations. For example, concentration of methylparaben in Andrographis paniculata (herb known for its anti-inflammatory activity) is only 0.0008% of its weight 16. Thus, paraben intake from plant sources is negligible 22. Concentration of parabens in cosmetic formulations can reach up to 0.8% 21 that is nearly 1000 times more than in plant sources.  Due to the low level of accumulation in plants, all industrially used parabens are produced synthetically 22.

Parabens in our body
Parabens consumed with food are fully metabolized: enzymes of our digestive system break these chemicals into smaller compounds that are further excreted with urine 17. Parabens from personal care products are absorbed through the skin. Skin enzymes cannot process all consumed parabens 14, and some amount of them is retained in the body tissues 5; 13. Occurrence of INTACT parabens in urine after application of paraben-containing cosmetics confirms that our body cannot fully metabolize these chemicals 14, 23, 24. Interestingly, women using personal care products more extensively than men have 4-times higher levels of parabens in urine 23.

parabens, metabolism of parabens, parabens from food, cosmetics, health

Parabens in our body (based on the studies 5, 13, 14, 17)

Are parabens dangerous?
Nowadays the safety of parabens is a hot topic extensively discussed in media and scientific literature. But what are the risks?

1) Cancer
It was shown that parabens can mimic oestrogens 4, 12 - primary female hormones regulating reproduction system and metabolism. Surprisingly enough, these hormones are also directly involved in the development of cancer 18, 19. They stimulate cell division that increases chances of genetic errors leading to the formation of malignant tumors 18. Parabens are weak oestrogens. It means that to have any negative effect, the concentration of parabens in the cell has to be much higher than the concentration of estradiol - a natural female hormone 6, 9. Even though the role of parabens in cancer development has not yet been proven, occurrences of intact parabens in breast cancer tumors 5 raised significant concerns about the safety of these chemicals. Apart from parabens, many other cosmetic ingredients (UV filters from sunscreen cosmetics, aluminium chlorhydrate from deodorants) have oestrogenic activity. Thus, it is important to evaluate cumulative effect of these compounds on human's health 6 .

2) Increase of UV-damage
Occurrences of skin cancers even among young people have grown over the last decades. Scientists suspect that it can be related to the greater use of sunscreen cosmetics containing parabens 6. For example, methylparaben was shown to increase adverse effects of UV-light 10 leading to a damage of DNA. DNA is the ”storage” of information for normal functioning of our body 3,thus, defects in DNA greatly increase the risk of cancer.

3) Reproductive toxicity
Frequency of male reproductive disorders has significantly increasedover the last 50 years 2. Scientists demonstrated that paraben-containing diet correlated with development of reproductive disorders in rats 20. Currently it is not known if absorption of parabens through skin has similar consequences. This is rather important question, because many baby creams or wipes contain parabens 6.

4) Skin aging
Scientists showed that methylparaben might cause aging of keratinocytes – cells forming the outer layer of our skin 13.

Regulations concerning parabens
JECFA* 2007 postulated the withdrawal of propylparaben and butylparaben from the food additives list due to potential risks of reproductive and endocrine toxicity 15. But since regulations concerning cosmetics are less strict, all parabens are still allowed for use in cosmetic products at certain concentrations 21.

Conclusions
According to the U.S. Food and Drug Administration and the World Health Organization, parabens do not pose a risk to our health at low concentrations 8. But if person uses many paraben-containing products daily, is the risk still minimal? The allowed daily intake for parabens was calculated to be 0-10 mg/kg of body weight/day 7. The maximum cumulative amount that the average person can potentially consume during the day with food, pharmaceuticals and cosmetics is at least 10 times lower than the allowed limit 22. However, the allowed daily intake was calculated based on orally consumed parabens only. What about parabens absorbed through our skin?

So far, we cannot be certain that parabens from cosmetics do not pose extra risks to us. All we know is that our digestive system metabolizes all parabens from food and then our body gets rid of them 17  whereas our skin cannot process these chemicals and part of them does accumulate in the body 5, 13, 14. Therefore, it is reasonable to assume that the biggest danger of parabens comes from personal care products. For that reason, many researchers insist on re-evaluation of these chemicals due to their oestrogenic activity.

Unfortunately, the cosmetic industry had some precedents when ingredients used for decades were found to be toxic (for example, dibutyl phthalate). Can it be the same story with parabens? Debates about safety of parabens are still ongoing and it might take many years before we know the truth. In the meanwhile, let’s try to limit our consumption of these chemicals. Be especially careful while choosing cosmetics for your baby. Check the list of ingredients of a personal care product that you want to buy and think again if you find parabens in the formulation (they are always closer to the end of the list). Maybe it is better to take a paraben-free product? Better be safe than sorry.

This article is based on reviewing multiple studies published in peer-reviewed scientific journals.

*JECFA - The Joint Food and Agriculture Organization (FAO) and World Health Organization (WHO) Expert Committee on Food Additives

What do you think about parabens? Let's discuss it here!

References:

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  7. EFSA. 2004. Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food on a request from the Commission related to para hydroxybenzoates (E214 –E219). The EFSA Journal 83: 1–26. Available here
  8. Food and Drug Administration. Parabens. Available here.
  9. Golden R, Gandy J, Vollmer G. (2005). A review of the endocrine activity of parabens and implications for potential risks to human health. Crit. Rev. Toxicol. 35: 435–458.
  10. Handa O, Kokura S, Adachi S, Takagi T, Naito Y, Tanigawa T, Yoshida N, Yoshikawa T. (2006). Methylparaben potentiates UV- induced damage of skin keratinocytes. Toxicology 227: 62–72.
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  17. Lakeram M, Lockley DJ, Sanders DJ, Pendlington R, Forbes B. (2007). Paraben transport and metabolism in the biomimetic arti1⁄4cial membrane permeability assay (BAMPA) and 3-day and 21-day Caco-2 cell systems. J. Biomol. Screen. 12: 84 –91.
  18. Lonning PE (ed.). (2004). Endocrinology and treatment of breast cancer. Clin. Endocrinol. Metab. 18: 1–130.
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  20. Oishi S. (2001). Effects of butylparaben on the male reproductive system in rats. Toxicol. Ind. Health 17: 31–39
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Comments

2
Liz's picture

For sure, parabens are not good... But all this eco-cosmetics without parabens and other bad stuff cost much more!

Natalia's picture

Yes, paraben-free cosmetics are more expensive. There are few reasons for that. The most important one is that a producer has to find an optimal combination of antimicrobial ingredients that will successfully preserve a cosmetic product for a certain period of time. Parabens are very efficient as preservatives, and, on top of that, they are cheap. Thus, using alternative, more expensive preservatives will already increase the price of a final product. It is also common that a paraben-free product has shorter shelf-life comparing to the one preserved with parabens.