Parabens have been been used since the 1920s safely as preservatives in skin care products, cosmetics and various other toiletries items used in our every day life. Parabens are also present in certain food such as blueberries, strawberries, grapes, barley etc though in small quantities. Parabens are also used in pharmaceutical companies in various medications. Even though they’ve been around for 70 years, parabens still remains a controversial ingredients in the skin care industry. They were first victimised as sensitisers that are able to cause contact allergic dermatitis. In the recent years, parabens are again under scrutiny as potential endocrine disruptors acting as the hormone estrogen. They have also been falsely linked to breast cancer and infertility.

Now let’s see if all these claims are true! Before we dive into the research available on parabens, let’s understand a little background on these molecules and how the processed inside our body.

Background on paraben

Parabens are esters of parahydroxybenzoic acid (PHBA). There are different classes of parabens: methyl, ethyl, butyl, and propyl – paraben are the four most commonly used ones with a good track record.

Why are parabens present in skin care products and cosmetics?

• Effective antimicrobials at even low concentrations hence acts as preservatives.
• Minimal toxicity
• Chemically inert
• Odourless
• Low cost
• pH neutral
• They have been used safely since the 1920s as have been extensively studied for the safety profile in humans

With such advantages properties, a number of skin care products, cosmetics contain paraben as the choice of preservative.

Parabens as sensitisers

Parabens were labelled as contact sensitiser i.e Able to cause contact allergic dermatitis when applied to the skin. However, cases of paraben allergies have been consistently low with parabens being the culprit in only ~0.6 to 1% of the individuals with contact allergic dermatitis.

Most of these paraben allergies occurs in individuals with compromised skin barrier such as when products containing parabens were applied on eczematous or wounded skin.

An interesting observation called “PARABEN PARADOX” in which the same above individuals who reacted to paraben when applied to compromise skin, didn’t have any problems with the same paraben containing cream was applied to normal skin.

Parabens were even named the contact non-allergen of the year in 2019 by the American contact dermatitis society. Parabens are also the least allergenic preservative present in the market

Parabens as endocrine disruptors

It has been shown in vitro studies (lab studies) that parabens are able to bind to estrogen receptors. Amongst the various parabens, butyl paraben has the highest oestrogenic activity but overall has a weak oestrogenic potential and is 10,000 times less potent than the naturally present hormone estradiol. When lab animals was subcutaneously injected with high dose of paraben it was shown to cause increase in the size of the uterus. Though these findings may seem alarming, they do not represent the effects of parabens in humans.

Though parabens may act as endocrine destructors in vitro, there is no evidence that they are endocrine disruptors in humans.

Paraben linked to breast cancer

As paraben and can mimic estrogen and bind to estrogen receptors, there is a theoretical risk that they could increase the risk of breast cancer. However as stated earlier, parabens have only a weak oestrogenic activity. Even if they can bind to these estrogen receptors, there is no evidence that it can produce any effects in humans. Another reason why parabens are linked to breast cancer is because some studies were able to isolate parabens from cancerous breast tissues. But most of the studies came that came to this conclusion did not assess the presence of parabens in normal breast tissue.

One study found that parabens were present in the adjacent normal breast tissue as well.

One epidemiological study reported no increased risk of breast cancer incidence in patients using antiperspirant or deodorants. However details on the composition of these products were lacking from this study.

So far, there is still no convincing evidence that parabens increases the risk of breast cancer.

Parabens and infertility

Consequences of demonising parabens

• With companies being forced to cater to a market that embraces “Paraben free“, alternative preservative with lesser known properties and effects on humans are being used instead.
• Avoiding the use of preservatives in cosmetics and skincare products is dangerous as this provides a favourable environment for micro organisms to grow which can result in various skin infections.
• Skin care marked as “paraben free” are more expensive due to the use of other more expensive preservatives and because “paraben free” is a great marketing strategy. This would prove to be too expensive for patients who depend on moisturisers or other products to help maintain a healthy skin especially in countries like India.

For these reasons use of parabens have not been banned from cosmetics or skincare products as the benefits of these molecules far out weighs their theoretical in vitro or animal studies risks

I am not saying that parabens are 100% safe, and completely risk free, because nothing on earth is risk free. The best approach in such situation is to try to understand the available data and to weigh the benefits against the risk.

So who should use “paraben free” products?

Michelle from Lab Muffin, who talks about the science of beauty, wrote such a great blog posts on this topic as well. Do check that out for an even detailed read.