Parabens are a group comprised of various types for providing antibacterial, anti-fungal and antimicrobial properties. They are methyl, ethyl, propyl, butyl, isopropyl and isobutylparaben. Let us heed the trusted modern toxicological axiom pertinently observed and recorded by Paracelsus in 1538: “All things are poison and nothing is without poison. Solely the dose determines that a thing is not a poison.”
Parabens (hydroxybenzoates) are one of most wrongly maligned ingredients in the cosmetic industry. Most “natural” companies embelish a study done by Dr. Darbre and implicate that using any cosmetic with parabens will put you at a higher risk of breast cancer. The fact that only a handful of scientists felt any need to comment on this study goes unmentioned. They also would like you to believe that parabens are no good for sensitive and eczema prone skins as they will cause allergies.
Parabens do have direct correlates in nature. In fact, all plants normally produce p-hydroxybenzoic acid, albeit in small quantities (1). Well-known plants known to significantly synthesise parabens as defensive chemicals against attack by micro-organisms include carrot, olive, cucumber, honeysuckle and ylang ylang, mango, raspberries and blackberries..(2,3,4,5)
All of the above mentioned foodstuffs naturally contain phytoestrogens. All are in fact endocrine disrupters, ie. exogenous agents that interfere with the production, release, transport, metabolism, binding, action or elimination of natural hormones in the body. Most phytoestrogens show some beneficial effects on estrogen-dependent disease. However, these can also promote tumour growth. Just like the improperly maligned parabens, risk/benefit analysis is dependent on dose and circumstances, not the mere name of a single or group of chemicals (parabens), natural or otherwise. Parabens offer substantially less risk than naturally occurring endocrine active chemicals in the diet such as the phytooestrogen daidzein.
The human diet contains several nonsteroidal estrogenic compounds structurally similar to natural and synthetic estrogens and antiestrogens. Dietary estrogens are either produced by plants (phytoestrogens) or by fungi that infect plants (mycoestrogens). The estrogenic potency of synthetic estrogenic chemicals is very limited, phytoestrogens are potent and may trigger many of the biological responses that are evoked by the physiological estrogens. The natural endocrine disrupters genistein, coumestrol and zearalenone (mycotoxin) stimulate the transcriptional activity of estrogen receptors at considerably lower concentrations (100X) than synthetics.
Parabens are not carcinogenic or mutagenic. The Darbre study showed that parabens can be absorbed through the skin and accumulate in breast cancer tissue in their original form, without being degraded. The study also did not identify the route by which the parabens entered the body. No data was collected as to whether or not the patients from whom the tumours were excised used personal care products that contained parabens. Scientists have also proposed that parabens were present in the tissues samples only due to contamination because they were also detected in the control samples, which should have been clear of all traces of the compound.
For this, and several other reasons, this study has been largely discredited by many cancer research organisations, and much of the rest of the scientific community. One of the most frequently quoted facts about parabens is that they mimic oestrogen and are endocrine disruptors. This is not true.
The cancer argument is based on the ability of parabens to mimic the hormone estrogen, which is known to play a role in the development of breast cancers. Laboratory research however has shown that they would have to be 500 to10,000 times more potent to do this, and even the strongest oestrogen mimetic out of the parabens – butylparaben – is 100,000 times weaker than oestrogen.
In a review of the estrogenic activity of parabens, (Golden et al., in Critical Reviews in Toxicology, 2005) the author concluded that based on maximum daily exposure estimates, it was implausible that parabens could increase the risk associated with exposure to estrogenic chemicals. Methyl and propyl parabens have such weak oestrogenic activity that no activity was detected in vivo in classical uterotrophic assays using high dose oral or subcutaneous rodent administrations (AFC Panel, European Food Safety Authority, 13 July 2004).
Butylparaben showed oestrogenic activity 100,000 times weaker than oestradiol. This has been wrongly interpreted as parabens mimic oestrogen. Oestrogenic activity and oestrogenic mimickry are very different effects. Oestrogenic activity is simply a measure of the relative power of a substance to bind to oestrogen receptors in the body. It is expressed as a comparative figure to oestradiol. Once it is bound it may just sit there and no nothing or it may mimick oestrogen.
It is the comparison of the effect on global gene expression that determines the extent to which a substance truly mimics oestrogen….
Other studies suggested (Oishi) that propylparaben and butylparaben may produce adverse reproductive effects in young male rats when given via the dietary route for 8 weeks. This study showed lower sperm count etc. However an attempt to reproduce those results FAILED. Even though they used the same protocol and rat strain.
Another study injected propylparaben and butylparaben subcutaneously into pregnant mice during day 1-4 of pregnancy at doses up to 35mg/animal/day. The study found no adverse effects, whereas 17B-estradiol produced the expected termination of pregnancy.
In another study which examined the systemic exposure to parabens after oral, topical and subcutaneous administration….the results were “Our results suggest that the topical use of parabens does not produce a significant systemic exposure to the parent compounds, but to a metabolite PHBA which is non-toxic, ubiquitous in human nutrition, an essential and natural constituent of plant and mammalian organisms and possesses no or neglible oestrogenic activity.”
Another study examined whole body topical application of 2% butylparaben. Normal concentration is 0.02% so it used 100 times more. Researchers than measured the concentrations of various hormones – reproductive, thyroid and concluded that the concentrations achieved did not influence hormone levels. Butylparaben does not affect the reproductive and thyroid systems. Butylparaben does not accumulate in the body and is excreted in the urine intact.
What about sensitivity?
As far as parabens causing allergies, contact sensitisation has occurred when parabens have been applied to damaged or broken skin but high concentrations of 15% in patch testing are needed to elicit reaction in susceptible individuals. These amounts they are referring to do not occur in cosmetic use.
According to the American Academy of Dermatology “The best preservatives for sensitive skin are those containing parabens” (2002 Prof Zoe Draelos, Summer Scientific Meeting, New York, AAD, 2002.)
Parabens are used in cosmetics because they have been shown to be very effective and are stable under heat. The majority of consumers have no allergies to them. In addition, the American Cancer Society has concluded that there is no good scientific evidence to support the claim using cosmetics containing parabens increases an individual’s risk of developing breast cancer.
According to the American Academy of Dermatology “The best preservatives for sensitive skin are those containing parabens” (2002 Prof Zoe Draelos, Summer Scientific Meeting, New York, AAD, 2002).
The Scandinavian Society of Cosmetic Chemists (SCANCOS) defended the safety of parabens at its Sustainable Cosmetics Conference, held Nov. 5-6, 2009 in Malmö, Sweden. Florian Schelauf from Colipa presented the findings from a study in 2009 on rats.
The study was performed at the request of the Scientific Committee on Consumer Safety for more data on the longer parabens propyl and butylparaben, following research that claimed the commonly used preservative may affect the reproductive and hormonal systems of the body.
According to Schellauf, butylparaben is largely metabolized before entering the systemic circulation, allowing only trace amounts of the substance to be present in the blood stream after topical application. This research refuted studies claiming that parabens absorb into the skin and accumulate in the body, possibly causing cancer. Schellauf’s research drums up support for the safety of the effective preservative.
The study showed that parabens are well absorbed after oral administration but only partially absorbed after dermal exposure. In addition the compounds are fully metabolised before they enter the blood stream. Blood plasma tests highlighted only the presence of the paraben metabolite p-hydryoxybenzoic acid and no concentrations of the parabens themselves, regardless of which paraben was used and how it was applied (oral, dermal or subcutaneous).
p-hydryoxybenzoic acid does not have any oestrogenic effects and is found widely in plants and human food, so trace exposure in the human organism poses no health risk. The study confirms the results of a number of research studies, which concluded from their work that parabens are metabolised rapidly and to a large extent in living organisms and therefore cannot exhibit any adverse effects. In conclusion Schellauf stated that “PHBA (p-hydroxybenzoic acid) is not known to have any estrogenic special effects and is found extensively in plants and human food, so trace exposure in the human organism cause no health risk.”
“The study confirms the results of a number of research studies, which concluded from their work that parabens are metabolised rapidly and to a large extent in living organisms and therefore cannot exhibit any adverse effects,” – said industry trade body Colipa.
From this aspect, there is no need to panic. The real point of the situation is that much of the concern spread over their use is based mainly on a claim to have detected them in human breast cancer tissue. This study has been widely ridiculed in the scientific community, as the results were wrongly interpreted, and it is by no means conclusive that parabens were actually present in the tissues (given that they were also found at similar concentrations in the “blank” controls!).
Cosmeticsinfo.org makes the argument after also weighing all the research that many opponents to this debate again, show their results through testing on lab animals. This argument is weak and is inconclusive since we are not lab animals. Some of these studies suggest a very weak estrogenic effect of Parabens. However, these studies, which have been conducted in animals, are observed only when they are dosed with extremely high amounts of Parabens….. far greater than anyone would be exposed to under actual conditions of use or with repeated use. The simple fact is that Parabens are 100,000 times weaker than natural estrogen in the body……. far too weak to have any effect in humans.
The FDA supports the use of Parabens as does the European Union….and under regimented testing by the cosmetics directive of the European Union they too, found no direct correlation of Parabens and cancer.
The fear of parabens has caused an increase of cosmetic allergies. The preservatives being used to replace them require a higher percentage to ensure safe preservation. Some of the more natural preservatives being used have gaps in their microbial coverage. Leucidal Liquid PT ( Lactobacillis Ferment) being one of them. Microbiologists do not recommend the use of this preservative. Consumers need to realise that safety of the cosmetic is more important than the preservative being natural. It is by far more dangerous to use a contaminated product, than it is to use a product with parabens in it.
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- Systemic exposure to parabens: Pharmacokinetics, tissue distribution, excretion balance and plasma metabolites of [14C]-methyl-, propyl- and butylparaben in rats after oral, topical or subcutaneous administration. Food and Chemical Toxicology
Volume 50, Issues 3–4, March–April 2012, Pages 445–454
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