skin, parabens are rapidly absorbed and metabolized, but they also accumulate in the human body. In
2002, parabens, due to their estrogenic activity, were found to cause increased uterine growth in
animals. The same study first linked parabens to the proliferation of two estrogen-dependent human
breast cancer cells (Darbre et al. 2002). Two years later, parabens were found in breast milk and
breast cancer tumors. In a 2004 study, tests found parabens in breast cancer tumors in nineteen out of
twenty women with breast cancer (Darbre et al. 2004). This study, while small and statistically
insignificant, proves the ability of paraben preservatives to penetrate skin and accumulate in living
tissue, such as breasts. In the body, parabens mimic our own hormones and can have an endocrine-
disrupting action. The hypothalamus, the ovaries, the thyroid—parabens affect virtually every system,
even though their action is much milder than that of natural estrogens and other xenoestrogens
(synthetic estrogens that mimic natural hormones).
Granted, science currently has no direct evidence that any cosmetics containing parabens result in a
higher risk of cancer, and the American Cancer Society insists that parabens are perfectly safe from
an oncologist’s point of view. The cosmetic industry’s panel, the Cosmetic Ingredient Review (CIR),
reviewed the safety of methylparaben, propylparaben, and butylparaben in 1984 and concluded they
were safe for use in cosmetic products at levels of up to 25 percent of the finished product. However,
not a single study has yet focused on chronic, decades-long, direct exposure to parabens that act
synergistically with other xenoestrogens and the body’s own estrogens.
While the jury is still out, the use of parabens, often disguised by tongue-twisting names such as
benzoic acid, isobutyl p-hydroxybenzoate, or p-methoxycarbonylphenol, has been strictly regulated in
European-made cosmetics, and current European Union legislation allows their use only in extremely
weak concentrations. It is unlikely that parabens will be removed from cosmetics sold in the United
States anytime soon. There is strong support of paraben use coming from the chemical industry,
especially preservative suppliers, which is very understandable.
PRESERVATIVES TO AVOID
Other preservatives to avoid include imidazolidinyl urea and diazolidinyl urea. Often disguised as
Germall 115 and Germall II, they are a mixture of allantoin, urea, and formaldehyde. Both
preservatives are known skin irritants (de Groot et al. 1988; Bosetti et al. 2007). During use, they can
release formaldehyde, whose ability to increase the risk of cancer is well-documented (Blackwell et
al. 1981). In liquid form, formaldehyde is contained in other widely used preservatives as DMDM-
hydantoin and quaternium-15. Beginning in September 2007, the European Union has banned the use
of formaldehyde for embalming purposes. Bronopol, often listed as 2-bromo-2-nitropropane-1,3-diol,
can contribute to the formation of cancer-causing nitrosamines, according to the FDA. It can also
break down to produce formaldehyde. European regulators have also questioned the safety of
iodopropynyl but ylcarbamate (IPBC), a common wood preservative used in cosmetics, and may
restrict its use in moisturizing body lotions. Many agencies are concerned about the levels of iodine
found in IPBC, and regulators claim that iodine may be absorbed into the bloodstream, travel to the
thyroid gland, and affect its functioning.
“Artificial preservatives are only necessary if your product formulation is weak or unstable,” says
Roger Bars by of Weleda. “If you dilute your ingredients [with water] to make the product cheaply,
then you will need artificial preservatives. Also if your formulation is not balanced and carefully