The outcome of a recent Chicago Tribune investigation that uncovered toxic levels of mercury in some skin-lightening creams was certainly troubling. And although mercury was not listed in the tainted products' ingredients, you may be surprised at some of the common, yet potentially harmful ingredients that are often used in some of your favorite skin care products.

Parabens
Parabens (commonly listed as methylparaben, ethylparaben, butylparaben or propylparaben) are a group of chemicals used as preservatives in a wide range of cosmetic, personal care and food products. Applied topically via creams or moisturizers, parabens can permeate the skin and make their way into the body.

The trouble with parabens lies in their ability to mimic estrogen, potentially disrupting normal endocrine function and hormone activity. In a recent study, pre-pubescent female rats were exposed to parabens over the course of three weeks¹. Researchers found that these chemicals suppressed normal hormone responses, actually delaying the occurrence of certain reproductive changes.

Diazolidinyl Urea
Another ingredient to look out for is diazolidinyl urea, an antimicrobial preservative used in many skin care and cosmetic products. Diazolidinyl urea also acts as a formaldehyde releaser, which may be a problem for those with sensitive skin or chemical allergies.

A recent article in Contact Dermatitis stated that 15% of all reactions to products containing common formaldehyde releasers are caused by formaldehyde². The study authors noted that because there is no way to determine how much formaldehyde will be released by certain products, those who are sensitive to this chemical should avoid all products containing formaldehyde releasers, including diazolidinyl urea.

Phthalates
For those using pleasantly scented skin care creams and products daily, phthalates may be hard to avoid. They are widely used to help these scents last longer, but are often hidden under the vague ingredient name “fragrance.” One recent study analyzed the development and urine concentrations of chemicals in 1,500 pre-pubescent girls and found that exposure to phthalates (especially those found in fragranced lotions and shampoos) was associated with earlier breast development³. Much like parabens, phthalates may affect normal hormone activity.

Skin care creams, lotions, moisturizers and other products can be effective tools for promoting healthier, younger-looking skin. It is important, however, to consider the effects that each ingredient may have on your health. I suggest closely inspecting the ingredients of your favorite products to weigh the risks of daily application and exposure.

Fortunately, there are many popular skin care products formulated with natural plant-based compounds and nutrients that are free of these potentially hazardous ingredients, while still providing excellent and effective anti-aging benefits.

As always, to your good health,
Dr. Allen S. Josephs

1. Vo T, Yoo Y, Choi K, Jeung E. Potential estrogenic effect(s) of parabens at the prepubertal stage of a postnatal female rat model. Reprod Toxicol. June 2010 29(3):306-16.

2. de Groot A, White IR, Flyvholm MA, Lensen G, Coenraads PJ. Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy. Part 2. Patch test relationship to formaldehyde contact allergy, experimental provocation tests, amount of formaldehyde released, and assessment of risk to consumers allergic to formaldehyde. Contact Dermatitis. January 2010 62(1):18-31.

3. Wolff M, Teitelbaum S, Pinney S, Windham G, Liao L, Biro F, et al. Investigation of relationships between urinary biomarkers of phytoestrogens, phthalates, and phenols and pubertal stages in girls. Environ Health Perspect. March 22, 2010.