I always wanted to write about the parabens compounds. Not only they have sparked my chemical interest but also caused an alert when buying cosmetics, food and even pharmaceutical preparations.
Chemically speaking, they are esters of para-hydroxybenzoic acid, commonly known as parabens. Among them, it stands out the methylparabens (e2189), propylparabeno (E216) or the butylparabeno. Thus, the difference between them depends on the alkyl group (R in the figure). These are used as broad spectrum preservatives because they have antibacterial and antifungal properties and therefore destroy germs that can grow in the environment, such as those containing oil and water.
It does not seem much to tell, however a deeper analysis would reveal that we can talk a lot about parabens. My curiosity about these chemicals began, and sorry for the advertisement, buying “Deliplus” cosmetics (Mercadona supermarkets) . These products can be read on the cover “Parabens free. Perfume without allergens. Not tested on animals” which added to the price, caught my attention and I decided to buy it more. I questioned myself about the product whether it was just a publicity gimmick or a chemical compound that goes beyond. And yes, after a little bit of research, there is much controversy surrounding parabens, which in principle are safe because they are absorbed, processed and excreted quickly (according to research, parabens are metabolized by the liver and kidney and excreted in the Urine1) although its synthesis is synthetic.
However, the discussion is still open since they have been associated with cancer, more particularly breast cancer. Several investigations suggest that continuous exposure to parabens can hormonally unbalanced and thus the female reproductive organs. According to the article “Tangentes1” “In the isopropylparaben case, other research has shown a significant increase in the weight of several organs such as the liver, kidneys, ovaries and adrenal glands and thyroid, but show no evidence of increased body weight”. Also, according to L.Barr et al.2, they studied the relationship between the detection of parabens and breast different areas in humans. Their results showed detection of one or more parabens in 158 of 160 samples of breast cancer tissue from primary mastectomies. Also detected the 5 studied parabens (methyl, ethyl, n-propyl, isobutyl and n-butyl) in 96 of the 160 samples with the n-propyl, the highest concentration in the underarm area. It follows as a source of the compounds to deodorants, that are typically often used. I write “often” because of the 40 women donors, 7 were reported to have never used deodorant, so some other environmental source must be considered, because, as mentioned at the beginning, parabens are used as preservatives in many products from food to drugs.
It is true that there are several studies showing that parabens, structurally similar to estrogens, have a weak estrogenic action. They have an hormone mimic action3 by binding to its receptors on cells and causing also gene expression generally regulated by estradiol (estrogen) listed as a causes of tumor cells of breast cancer.
Just one more point. The label “Paraben” can hide therefore a bit of marketing strategy, as some soaps, scrub creams, etc, hide a formulation under this motto, which is no water and oil based and therefore, there is no need of preservatives.
Finally, as a positive note, saying that the GEDCT (Spanish Group of Cosmetic Dermatology and Therapeutics), the AEDV (Spanish Academy of Dermatology and Venereology) indicate that “at present the percentage of parabens used in cosmetics is so low that possible adverse effects in healthy skin are practically nil, contrary to what happened for several décadas1 “.
Thus, it is up to our parabens consumption, but as consumers we must be informed and knowing what we buy.
To say, this it is my first participation in the XIV Biology Carnival Biotay’s blog. It is recommended to take a look to other nice contestants 🙂
2 “Measurement of paraben concentrations in human breast tissue at serial locations across the breast from axilla to sternum”. Journal of Applied Toxicology.