Category Archives: skincare controversies

Paraben in skincare and cosmetics

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.

Metabolism of parabens

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?

Individuals with a known allergy to parabens should opt for paraben free products. or if paraben free is your personal choice.

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.

Are antiperspirants and deodorants safe?

Aluminium has been shown to possess some undesirable biological effects on human body and exposure to high doses of aluminium has been linked to an increased risk of breast cancer and Alzheimers’s Disease.

Why did the controversy exist between breast cancer and antiperspirant?

As a majority of breast cancer occurs in the upper outer quadrant of the breast it was theorised that regular use of underarm cosmetics such as antiperspirant could potentially contribute to the increasing number of breast cancer detected in this site.

  • It was also shown in some studies that a concentration of aluminium was found in breast cancer tissues.
  • In vitro ( laboratory) studies have shown that aluminium can cause DNA instability and can promote cellular proliferation thus could potentially cause cancer.

What do the recent human studies say?

Many studies support the fact that the higher amount of breast tissue present in the upper outer quadrant of the breast is the reason for the increase number of breast cancer detected in this area and not because of it being in close proximity to the axilla (under arm).

Other studies have also shown that aluminium was found to be equally present both in the cancerous tissue as well as normal breast tissue.

The absorption of aluminium present in antiperspirant through the intact skin is very minimal and not significant enough to cause breast cancer.

Systematic analysis of two case-control studies has found no association between the use of antiperspirant and increase risk for breast cancer.

Does aluminium in antiperspirant cause Alzheimer’s disease?

A possible link between aluminium and Alzheimer’s disease was questioned when laboratory studies of high doses of injected aluminium was shown to cause neurofibrillary tangles (characteristic of Alzheimer’s disease)in rabbit brains i.e aluminium is neurotoxic to animal brains. This finding dates back to 1965, and years later it still remains a controversy.

Studying the association between aluminium and Alzheimer’s disease (AD) has been difficult due to the ethical issues in obtaining brain tissue for biopsies. The study so far have been based on autopsied brain specimens from patients with AD. This does not answer whether the increase aluminium concentration found in these specimens were the cause of the disease or a consequence of it.

As Alzheimer’s disease is a chronic disease, prospective studies aiming to determine the association between exposure to aluminium and the disease are met with many hurdles. AD Causes significant memory loss (dementia), studies relying on patients account of their history of exposure to aluminium in the past for example use of aluminium-based antiperspirant are biased, as patients are unable to recall correctly such exposures. Few studies have relied on the accounts given by the patient’s partners who may not have a correct idea of such exposures.

Therefore the association between aluminium exposure be it from our diet or water or underarm cosmetics and Alzheimer’s disease will always be a controversy yet to be proven.

What we know so far?

As stated earlier aluminium present antiperspirant is not significantly absorbed through the skin. The minimal amount that is absorbed is effectively excreted via the kidney before reaching the brain.

Therefore antiperspirant use is not likely to cause Alzheimer’s disease.

Presently there is no strong scientific evidence linking exposure to aluminium (including aluminium in anti-perspirant) as a causative factor To the development of Alzheimer’s disease