What are parabens and why do we care?

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What are parabens?

The word ‘Paraben’ is an abbreviation for para-hydroxybenzoic acid (PHBA). Parabens are an ester of PHBA, and act as a commonly used preservative in cosmetics, food, and pharmaceutical products. There are a few different types of parabens widely used for their antibacterial and antifungal properties. Parabens are hypoallergenic and cheap to produce. By decreasing the growth of bacteria and mold, parabens increase the shelf life of cosmetic products. Parabens were first introduced as an ingredient in the early to mid 1900s. They’re used to prolong shelf life in many health and beauty products by preventing the growth of mold and bacteria.

Chemical structure of four different parabens
Methyl-, ethyl-, propyl-, and butylparabens are found ingredients commonly found in food, cosmetic, and pharmaceutical products.

Parabens cover an entire class of preservative, so they might be listed on a product label by different names. These include methylparaben, ethylparaben, propylparaben, butylparaben, isopropylparaben, or isobutylparaben. Each of these names represents a chemical structure that works a little bit differently.

Synthetic vs naturally occuring parabens?

All parabens used commercially are synthetically produced. PHBA is a naturally occurring chemical in fruits and vegetables (blueberries are often cited as an example). However, parabens are an ester of PHBA and not exactly the same chemical.  Additionally, the levels of this chemical present in edible plants are also extremely low in those foods.

Parabens are derived from a chemical known as para-hydroxybenzoic acid (PHBA) that occurs naturally in many fruits and vegetables, like blueberries and carrots,” said Kathryn St. John, the communications director at the American Chemistry Council. “PHBA is also naturally formed in the human body by the breakdown of some amino acids.” l

Some argue that since parabens are present in nature in various forms, they are safe to consume and use topically. Even if parabens such as propylparaben and butylparaben are present in foods, many edible plants contain compounds that are unhealthy or toxic at higher dosages – I’m thinking of oxalates in spinach, or phytates in nuts and seeds. Personally, I like to look to the historical precedent to find the wisdom inherent in years of anecdotal experimentation, followed by what science can elucidate for us in terms of mechanism and a more fine-grained understanding.

Types of parabens

If you remember your college chemistry class, you’ll recognize the IUPAC nomenclature used for the naming of chemical compounds: METHYL(1), ETHYL(2), PROPYL(3), BUTYL (4) for counting the number of carbon atoms in a branched-chain structure. What this means in parabens is that methyl paraben is the shortest, followed by ethylparaben, then propylparaben, butylparaben and so on.

Chemical structure of the same four parabens highlighting the minor differences between them.

According to this safety report,   ”parabens in cosmetic formulations applied to skin penetrate the stratum corneum [epidermis] in inverse relation to the ester chain length” . This means that parabens with shorter ester chain lengths (methyl, ethyl) are absorbed through the skin at a higher rate than those with a longer ester chain length (i.e., butyl).

The chemistry behind why parabens work behaves as a preservative

Parabens halt microbial growth due to their ability to interfere with the metabolism of microorganisms. The mechanics are not fully understood, but it is thought that parabens are able to pass through cell membranes and disrupt protein synthesis by interfering with a protein’s ability to fold correctly. This ultimately leads to cell death.

What products are parabens in and why?

Parabens in cosmetics

Parabens inhibit the growth of bacteria and fungi. Without the ingredient or a replacement, a cosmetic product would have a much shorter shelf life. Parabens are found in makeup, moisturizers, face cleansers , soaps, shampoos and conditioners, and shaving products, deodorant, sunscreens, shaving gels, toothpastes, and more. 

Parabens in food and drug products

Some processed foods also contain parabens, such as some kinds of beer, soft drinks, jam, ice cream, and more. Medications such as ibuprofen, acetomeniphen, Diphenhydramine, Fluoxetine, and others may contain parabens as an excipient ingredient.

The International Journal of Toxicology states that “Industry estimates of the daily use of cosmetic products that may contain parabens were 17.76 g for adults and 378 mg for infants.” 

One study done in 2005 detected methylparaben in 99.1% of the urine samples studied.

What does the FDA say about parabens?

The FDA considered parabens to be acceptable for use in commercial products. To quote FDA.gov: “Safety questions about the use of parabens in cosmetics center around parabens’ potential to act like estrogen, a hormone that can be associated with the development of breast cancer. Studies have shown, however, that parabens have significantly less estrogenic activity than the body’s naturally occurring estrogen. Parabens have not been shown to be harmful as used in cosmetics, where they are present only in very small amounts

The FDA also states that they are still investigating the effects of parabens contained within cosmetics on human health.

What does the EWG say about Parabens?

EWG & Methylparabens

EWG scores methylparabens as a 3 or a 4 on their ingredients ratings scale. Their main concerns center around endocrine disruption and topical allergic and irritation reactions.

EWG & Propylparabens

EWG scores propylparabens as a 4 – 6 on their ingredients ratings scale, depending on usage. Their concerns discuss developmental and reproductive toxicity, citing research on endocrine disruption. Environmental toxicity and topical allergic and irritation reactions are also mentioned as areas of concern.

EWG & Ethylparabens

EWG scores ethylparabens as a 3 on their ingredients ratings scale. Concerns discussed include endocrine disruption and environmental/wildlife toxicity. Topical allergies and skin irritation are also mentioned.

EWG & Ethylparabens

EWG scores butylparabens as a 5 – 7 on their ingredients ratings scale. Their concerns discuss strong evidence for topical irritation and allergic reaction. Developmental and reproductive toxicity concerns citing research on endocrine disruption are also discussed.

What does the EU say about parabens?

The European Commission issued a press release that stated limits for propylparaben and butylparaben in all cosmetic products, and banned them from products designed to be left on the diaper area of children under the age of 3.

What does the science say

The scientific literature reveals mixed opinions regarding parabens.

Parabens and hormones

The scientific consensus is currently that parabens do not accumulate in the body. However, it is acknowledged that we are constantly exposed to high doses of the chemical class. Parabens are known to be weakly estrogenic, which means that they can have some of the same effects as the hormone estrogen does in the human body (like taking a teeny tiny birth control pill). There are growing concerns with the way parabens can impact hormones, fertility, and birth outcomes, as well as causing skin irritation for sensitive individuals.

Parabens in the environment

Parabens may also be accumulating in the environment. A recent study found evidence of synthetic paraben byproducts in the tissues of dolphins, sea otters and polar bears. 

Parabens and cancer

Scientific studies have not found any clear link between parabens and cancer, but research is ongoing. According to one safety assessment, propyl parabens specifically are readily absorbed by the skin and gut, but quickly converted to metabolite that is excreted with no evidence of accumulation. However, another study found more than 5 different parabens present in 19 out of 20 human breast tumors examined. This doesn’t mean that parabens cause or contribute to cancer, but it certainly opens questions about how those parabens got into those tissues, whether parabens are equally present in noncancerous tissues, and how the high body burden of parabens contributes to their presence in tumor tissues. Propyl- and butylparabens specifically are still being investigated with regards to long-term fertility effects on young boys. High concentrations of butylparabens are associated with depletion of glutathione, which can indicate stress on the body. Endometrial cancer tissues have been found to contain intact paraben molecules in a higher concentration than the normal endometrium.

Parabens and Male Fertility

Scientists have been investigating the effects of parabens on male fertility. One study has shown decreased sperm count, motility, and daily sperm production in rats exposed prenatally to butylparaben. Another study demonstrated a significant decline in sperm concentration, count, motility, and morphology in sub fertile men over a 17 year period.

What alternatives exist to parabens?

Because parabens have been under an increasing amount of scrutiny in past years due to a public concerned with anything remotely connected to cancer, there are fortunately a number of alternative cosmetic products in almost every area that are formulated without parabens. There are a wide range of ingredients that can be used as an antimicrobial agent in cosmetic formulations.

Look for products that do not contain the following in the ingredients list: methylparaben, ethylparaben, propylparaben, butylparaben, isopropylparaben, isobutylparaben, or any other ingredients that end in “paraben”.

What highly rated products avoid this ingredient?

Avoiding parabens in food

Avoiding parabens, should you choose to do so, is not difficult. Read the labels on any processed foods you purchase, and avoid any brands that contain parabens in the ingredients as a preservative.

Avoiding parabens in makeup and other cosmetic products

Many popular makeup brands have responded to market demand by removing parabens from their formulations. If you wish to avoid parabens, check in the ingredients label on your products, and let the company know that you would appreciate a formulation without the preservative. I’ll list below some of my favorite brands that are completely paraben-free. I love and use products from the following brands:

Beautycounter is a leader in the clean cosmetics industry, and offers high-performance makeup and skincare. Their products are formulated without parabens, ethically sourced wherever possibly,  and highly tested for heavy metals. The skincare products and foundations staples in my routine.

100 Percent Pure uses natural pigments as the foundation for its very popular makeup line, and uses natural ingredients in its skincare lines as well. If you want high-performing makeup that is close to the earth, this brand has products you’ll love. Their mascara is to die for, and i love their primers and brow gels.

Other brands with stellar reputations and closely-vetted ingredients list include Crunchi, W3ll People, Lili Lolo, and Thrive Causemetics. Look for perfumes with the highest-standard ingredients at Phlur & Agent Nateur.


References and resources 

https://www.ewg.org/californiacosmetics/parabens

Adults use 17g of parabens per day https://www.ncbi.nlm.nih.gov/pubmed/19101832

Methyl and Propylparabens frequently detected in urine https://www.ncbi.nlm.nih.gov/pubmed/20056562

Butyl paraben and glutathion depletion https://www.ncbi.nlm.nih.gov/pubmed/30572011

Parabens in endometrial carcinoma tissue: https://www.ncbi.nlm.nih.gov/pubmed/31463755

Maternal paraben exposure and smaller female babies https://www.ncbi.nlm.nih.gov/pubmed/31248753

Growth in male children: https://www.ncbi.nlm.nih.gov/pubmed/28034559

Decreased sperm count, motility and Daily Sperm Production in rats with prenatal exposure to butylparaben https://www.ncbi.nlm.nih.gov/pubmed/31672375

“Sperm concentration, total count, motility and morphology significantly declined between 2000 and 2017” https://www.ncbi.nlm.nih.gov/pubmed/30389382

Parabens are weakly estrogenic https://www.sciencedirect.com/science/article/abs/pii/S0960076001001741?via%3Dihub

Parabens found in marine mammals https://www.acs.org/content/acs/en/pressroom/presspacs/2015/acs-presspac-october-14-2015/parabens-and-their-byproducts-found-in-dolphins-and-other-marine-mammals.html

A negative association between maternal paraben exposure and female birth outcomes https://www.ncbi.nlm.nih.gov/pubmed/31248753

Parabens found in breast tumors https://www.ncbi.nlm.nih.gov/pubmed/14745841

Paraben safety discussion https://www.ncbi.nlm.nih.gov/pubmed/23131320

Parabens as an exipient in OTC and prescription drugs https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4426043/

Parabens are hypoallergenic: https://www.ncbi.nlm.nih.gov/pubmed/30649006

Parabens and endometrial carcinoma https://www.ncbi.nlm.nih.gov/pubmed/31463755

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4426043/

Wikipedia page on parabens https://en.wikipedia.org/wiki/Paraben

Pubchem https://pubchem.ncbi.nlm.nih.gov/compound/7456

https://www.fda.gov/cosmetics/resources-consumers-cosmetics/cosmetics-safety-qa-parabens

https://www.fda.gov/cosmetics/cosmetic-ingredients/parabens-cosmetics

Discussion of “naturally occuring” parabens: https://www.ewg.org/enviroblog/2015/07/myth-natural-parabens

Parabens overview https://www.medscape.com/viewarticle/508430_2

A refresher on counting carbon chains https://en.wikipedia.org/wiki/Alkyl

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