In recent years, there has been a turn in the beauty and cosmetics industry against parabens. The reason? Some studies show high concentrations of parabens can weakly mimic estrogens (Toxicology and Applied Pharmacology, 2008; The Journal of Steroid Biochemistry and Molecular Biology, 2002). Other studies have shown parabens accumulate in human breast tissue (Journal of Applied Toxicology, 2004), which certainly sounds alarming, until you consider these parabens may be endogenously produced by the body, the by-products of natural processes; or more probabilistically derived from a variety of food sources, including blueberries, which contain far higher concentrations of parabens than the average personal care product. [Read more: The Real Dangerous Source of Parabens: Your Food?] In general, most physicians and scientists consider paraben exposure to be a minimal and non-significant risk (Critical Reviews in Toxicology, 2005). As Stanford-trained dermatologist Dr. Kathy Fields, M.D., of ProActiv and Rodan+Fields fame once told us in an exclusive interview, "The benefit of the higher calling is to give good evidential information to tell what is real and what is a lie; to help the consumer. It is so overwhelming, and there is also so much politics involved in some of the ingredients. Unfortunately a lot of misinformation goes the wrong way. No one wants cancer from a cosmetic, like in the case of the rumors about parabens. By the way, you see parabens all over the place. Did you know you just ate a spoonful of parabens?" The truth of the matter is, parabens prevent bacterial overgrowth, and I support Dr. Fields' opinion that statements otherwise are often political. For instance, oral contraceptives contain thousands of times the estrogen-mimicking potential of parabens. Foods like soy, wheat, barley, peas, and chickpeas are sources of isoflavones with dozens of times more estrogen mimicry than you get from the average dose of parabens in a skin care product. And, truth be told, some of the preservative alternatives used in place of parabens aren't so great either, as we will uncover below:
Parabens aren't in skin care and cosmetics products because manufacturers are cheap or trying to kill you. In fact, parabens are the only effective protection against most bacterial species (Cosmetics and Toiletries, 2005). The following paraben alternatives have been found to be effective against fungi, NOT many types of bacteria (Cosmetics and Toiletries, 2005):
These organic acids interact only with the cell wall of microorganisms. That does not kill the majority of bacteria, only fungi! By contrast, parabens will interfere with the metabolic pathways of bacteria (Cosmetics and Toiletries, 2005) in a manner similar to many antibiotics. Ingredients like phenoxyethanol, benzyl alcohol, and chloroacetamide added to these organic acids also does not help to improve their efficacy against bacteria (Cosmetics and Toiletries, 2005). Cosmetic and skin care products must undergo antimicrobial testing before being sold in the U.S. However, this does not mean your product with organic acid preservatives will not undergo significant bacterial growth if stored in a hot, humid place (such as your shower) or left open. Try it! I did, and my paraben-free shampoo gave me significant forehead acne, and my boyfriend experienced an unfortunate scalp rash. (Next time, I'll experiment with kits instead of ourselves!)
Despite the fact many products use benzoic acid instead of parabens for "safety" reasons, benzoic acid has one of the highest skin penetration abilities, penetrating the skin better than caffeine or testosterone (Regulatory Toxicology and Pharmacology, 2004). This means that benzoic acid delivers ingredients even deeper into your skin. This is not necessarily a bad thing - one reason for the efficacy of serums like my old favorite Skinceuticals CE Ferulic is penetration enhancers, like glycols. However, when used with other penetration enhancers, benzoic acid may increase the rate, or flux, with which they diffuse into the skin (Pharmaceutical Research, 1990). This is not a benefit: microencapsulation, liposomal delivery systems, and several other technologies are developed to slow down delivery of key ingredients into your skin, not speed them up. Many paraben-free products also regularly contain benzoic acid, but few people know that parabens are actually parts (alkyl esters) of a type of benzoic acid, p-hydroxybenzoic acid. For the ultra-scientific and curious, parabens are formed by reacting p-hydroxybenzoic acid with an alcohol (methyl, ethyl, etc.) in the presence of an acid, like sulfuric acid. Benzoic acid itself has not been found to be estrogenic in the human body, but some studies have shown estrogenic effects in mice (Environmental Research, 1997). Overall, benzoic acid is safe, but I would find another preservative system when working with glycol-containing serums. The reason? You don't want to accelerate the delivery of key ingredients into your skin, overloading receptors - instead, you want that nice, slow, sustained delivery process.
Despite the fact many products use benzoic acid instead of parabens for "safety" purposes, vitamin C and sodium benzoate (a preservative) will together form benzene, which has been associated with causing cancer (International Journal of Occupational and Environmental Health, 2007). A known carcinogen, benzene is associated with causing DNA strand breaks, and high levels of exposure have been associated with acute myeloid leukemia (AML), aplastic anemia, myelodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML) (Annual Review of Public Health, 2010). Typically, the dose of preservatives you get from a skin care product is negligible and does not pose a health risk. However, soft drinks also contain very low amounts of benzoates, and 2.5% of over 200 soft drinks tested with vitamin C and sodium benzoate were found to have levels of benzene above permissible levels (FDA, 2007). Using products with a high concentration of vitamin C can protect you. Benzene does not form at all if you use beauty products with a very high concentration of vitamin C and a low concentration of sodium benzoate (AIB International, 2006). This is because high concentrations of vitamin C cause for it to overwhelmingly act as a free radical scavenger rather than participate in the sodium benzoate reaction. In addition, keep your beauty products with vitamin C and benzoates in a cool, dark place. Higher temperatures and light incite the reaction to benzene (AIB International, 2006), so cooler temperatures and darkness will inhibit the reaction from occurring. The best solution, though, truth be told, is just to avoid products that contain vitamin C and benzoates altogether. We have some of the smartest readers in the world here at FutureDerm, and I know the questions are coming: How much vitamin C is needed to prevent the vitamin C + benzoate conversion to benzene? How cold should the room be? How dark? We are still researching these answers for the time being. Until we know, I would avoid products with vitamin C and benzoate preservatives altogether.
I understand concern about estrogenic mimicry - I lost my grandmother, to whom I was very close, to breast cancer many years ago. However, as a scientist, I feel that arguing about parabens is barking up the wrong tree. Regardless, if you are concerned, one acceptable system is the combination of diazolidinyl urea, sodium benzoate, and potassium sorbate (Cosmetics and Toiletries, 2005). This combination has been found to have promise against bacterial growth (Cosmetics and Toiletries, 2005).
I will also say this: While my product currently contains parabens, I may reformulate a version later without parabens for those who feel more comfortable with that option. I honestly don't mind doing so! However, I will always a.) continue to produce the original version, and b.) stand by the fact our product is safe. I mention this only because I do not want for anyone to think I am biased: My product contains parabens because the literature overwhelmingly suggests they are safe in the concentrations used in the product, even with repeated exposure, and I believe they are better in this formulation than the alternatives. Please do not think I am saying parabens are safe because our product happens to contain parabens.
Please keep the following in mind: