First – One of the original studies that linked parabens to mimicking estrogen.
Some alkyl hydroxy benzoate preservatives (parabens) are estrogenic, from the journal of Toxicology and Applied Pharmacology – (Routledge, 1998)
This study wanted to see if parabens could actually imitate estrogen. In the abstract of this study, Routledge confirms “that a range of alkyl hydroxy benzoate preservatives (parabens) are weakly estrogenic.” Butylparaben was seen to be 1-5 orders of magnitude less effective than naturally occurring estrogen.
However, there was an interesting difference was found in rats that were administered parabens either orally or subcutaneously (under the skin). Parabens administered orally led to inactive parabens while subcutaneous administration produce a “positive uterotrophic response in vivo, although it was approximately 100,000 times less potent than 17β-estradiol.” So, though parabens given under the skin were more effective than those given orally, they were still 100,000 times less potent than the body’s naturally occurring estrogen, 17β-estradiol.
The Routledge study leaves us with this ultimate caution –
“Given their use in a wide range of commercially available topical preparations, it is suggested that the safety in use of these chemicals should be reassessed, with particular attention being paid to estimation of the actual levels of systemic exposure of humans exposed to these chemicals.”
What are the implications of this study/Remaining questions?
Important implications from the subcutaneous effect of parabens suggest that parabens found in cosmetics or other topical applications could be more harmful than those found in food. After this study, the prevailing paradigm was that parabens could be used in safe quantities. But the question of quantity of exposure and effect still remained.
The following studies present challenges to the idea that parabens in small doses in products are safe.
#1 Concentrations of Parabens in Human Breast Tumors. – The Journal of Applied Toxicology, 13 May 2004 (Darbe)
This study wanted to see whether parabens could actually “accumulate in fatty components of body tissues in a similar manner to that of other lipophilic pollutants that are known to bioaccumulate”.
Previous studies have shown oestrogenic activity caused by paraben usage to have several side effects including:
- Increase in the growth of MCF7 human breast cancer cells which could however be mediated or blocked by the the antioestrogen drug ICI 182 780 .(Okubo et al., 2001; Byford et al., 2002; Darbre et al., 2002, 2003) Basically cancer cells could be reduced by a drug but what happens when this drug is not naturally occurring in your body while subjecting yourself to parabens?
- Oestrogenic activity in animal models in vivo in fish (Pedersen et al., 2000)
- Increase in uterine weight in immature rats (Routledge et al., 1998) and immature mice (Darbre et al., 2002, 2003)
- Alterations in reproductive function in male rats, including reduction in sperm counts (Oishi, 2001).
This study understood that “the presence of oestrogenic chemicals in the breast area could potentially influence both the incidence and treatment of breast cancer” and given the wide usage of parabens as a preservative in underarm cosmetics (deodorant/antiperspirant), it has been suggested that “regular application of such oestrogenic chemicals could influence breast cancer development” (Darbre, 2001, 2003; Harvey, 2003).
“However, the outstanding question remains as to whether parabens can enter and accumulate in the human breast.”
To test this, the scientists took extraction of parabens from human breast material and analyzed them by thin-layer chromatography, which is a method used to separate mixtures.
After experimentation, they found that “the total mean paraben level was found to be of the order of 20 ng g−1 tissue” which means that this “adds parabens to the list of environmental oestrogenic chemicals that can be found to accumulate in the human breast”
They also found that “paraben concentrations measured in tumours were unequivocally of the esters themselves which” which demonstrates that “at least a proportion of the parabens present in cosmetic, food and pharmaceutical products can be absorbed and retained in human body tissues…”
With regards to topical or oral consumption, oestrogenic responses in immature only occurred when parabens were administered subcutaneously or topically but not orally. This “suggests that skin penetration may be an important route for entry to the body.”
According to Scientific American, “What worries public health advocates is that while individual products may contain limited amounts of parabens within safe limits set by the U.S. Food & Drug Administration (FDA), cumulative exposure to the chemicals from several different products could be overloading our bodies and contributing to a wide range of health problems.”
In conclusion this study asks the scientific community to take into consideration the ability of “weakly oestrogenic parabens” to bioaccumulate. If Parabens are capable of accumulating and then the the safety low doses in permitted individual cosmetics, foods and pharmaceuticals may be called into question.
What are the implications of this study/Remaining questions?
This study found parabens in breast tissue. However, because darbe failed to test healthy breast tissue, we wouldn’t know whether the parabens found in the cancerous breast tissue is any different from those of healthy breast tissue. Also, existing parabens in cancerous breast tissue does not prove that parabens caused the cancer.
This does however, leave the unanswered question of what are the potential effects of Parabens if they are able to accumulate in the body?
# 2. Urinary Concentrations of 4 Parabens in the US Population: NHANES 2006 – 2006, from The Journal of Environmental Perspectives (Calafat 2010)
This study compared amounts of parabens found in different ethnicities and sexes. This study assessed the exposure to methyl, ethyl, propyl, and butyl parabens among people above or equal to six years of age and across varying ethnicities and sex between the years 2005-2006.
After analyzing 2,548 urine samples, they found “methylparaben (MP) and propyl paraben (PP) in 99.1% and 92.7% of the samples.”
Interestingly concentrations of “MP was significantly higher (p <or= 0.01) among non-Hispanic blacks than among non-Hispanic whites except at older ages (>or= 60 years).” Also “Adolescent and adult females had significantly higher (p < 0.01) LSGM concentrations of MP and PP than did adolescent and adult males.”
Simply put, ethnic minorities were more likely than their white counterparts and and females more likely than males to have parabens in their urine. According to the conclusion of this study, “Differences in the urinary concentrations of MP and PP by sex and race/ethnicity [is] likely reflect the use of personal care products containing these compounds.
The reason for this could be due to socioeconomic reasons and overall product usage. Ethnic minorities are statistically more likely of being in lower socioeconomic rungs leaving many with limited options in their product choices. As parabens are are among the cheapest preservatives, they are widely used in more cost effective products. Exposure to cheaper products means exposure to more parabens.
With regards to female versus male, According to The Environmental Working Group, the average woman uses approximately 12 products every morning while men use about 6. This is again a link to overall exposure.
So, if parabens could bioaccumulate we would see that, consumers exposed to more products containing parabens would have more parabens in their bodies….and that is exactly what we see.
#3 Parabens and Human Epidermal Growth Factor Receptor Ligands Cross-Talk in Breast Cancer Cells – Environmental Health Perspectives Journal, 27 October 2015 – Shawn Pan
This study wanted to see if chemicals not used in the petri dish experiments, that naturally occur in the human body could enhance or make worse the effects of parabens.
This study argues that previous studies did not take into account parabens coming into contact with other compounds in the body causing an increase in the effects of parabens, more specifically, Herugulin.
Heruglin, is a “ligand” or molecule that is a type of “human epidermal growth factor receptor” (HER). In this study, researchers wanted to see if HER’s like Heruglin would affect the “cell proliferation” or increase in cell production which is directly linked to cancer growth.
The results showed that HER ligands worked with Butylparaben to increase c-Myc mRNA, which is a type of mRNA that helps to create MYC Protein which is known to cause rapid growth of cancer cells. The combination also caused an increase in BY-474 which is a type of breast cancer cell line.
The conclusion states that “HER Ligands enhance the potency of BP” which suggests that “parabens might be active at exposure levels not previously considered” from studies in which the parabens were tested in isolation from other bodily compounds.
This study raises new questions about the behavior of Parabens in the human body rather than experimented in an isolated vacuum. If HER is able to produce an increased effect, what about smoking, alcohol consumption, environmental factors and other factors these experiments have failed to take into account ?
The studies in the 90’s conducted by Routledge and others, first made the link between parabens and estrogenic activity. Darbe in 2004, showed concentrations of parabens in cancerous breast tissue, but failed to test healthy breast tissue, rendering his study unusable for practical product changes.
Later in 2010, Calafat tested the paraben amount in urine samples across ethnicity and sex. Th results showed that increase in paraben use led to increase in paraben presence in urine. This helps to back up the findings in the Darbe study and the idea that parabens can bioaccumulate. Finally, the study in 2015 showed that the naturally occurring human growth hormone HER could enhance the oestrogenic effects of parabens, raising the question of the danger of other factors not previously considered.
Parabens are still deemed as safe to use by the FDA and so are still widely used as preservative in booth food and cosmetics. The treatment of chemicals seems to be one of innocent until proven guilty. This is a harmful and potentially detrimental way to treat chemical regulation. We believe to alway err on the side of safety and caution. Though considered safe in small doses, we have shown you studies that are beginning to suggest otherwise. It took decades before certain governments began to require a truthful depiction of the effects of cigarette smoke. We believe it is the responsibility of individuals and independent companies to provide the safest products possible while the government grapples with the conflict of interests public health and large corporations.
We believe that a chemical is not fit for mass production or human or animal consumption until it has been proven safe. Until governmental regulation has caught up with morality, for the good of all animals, we will continue to treat chemicals guilty until proven innocent.