I’ve been wading through State of the Science of Endocrine Disrupting Chemicals – 2012. The 289-page report was prepared by a group of experts for the United Nations Environmental Programme and World Health Organization.
It is dense and complex, but what I’ve been looking for is any acknowledgement that hormonal contraceptives are endocrine disrupting chemicals (EDCs).
Hormonal contraceptives clearly act as EDCs according to the definition used in this report:
An endocrine disruptor is an exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, or its progeny, or (sub) populations. A potential endocrine disruptor is an exogenous substance or mixture that possesses properties that might be expressed to lead to endocrine disruption in an intact organism, or its progeny, or (sub) populations.
Adverse health effects would include, in this context, anything that disrupts the reproductive systems of humans (and wildlife) or contributes to other health problems such as hormone-related cancers, thyroid-related disorders, cardiovascular disease, bone disorders, metabolic disorders and immune function impairment. Hormonal contraceptives certainly disrupt the reproductive system and have been associated with increased risk of cardiovascular events, loss of bone density, decreased immune function and, in some studies, increased risk for breast cancer. Metabolic disorders? Recent research suggests that long-acting progestin-based birth control may increase risk in obese women for Type 2 diabetes.
The only mention I could find of specific contraceptive chemicals is in section 3.1: The EDCs of concern. In a table under the sub-heading Pesticides, pharmaceuticals and personal care product ingredients, two key components of hormonal contraceptives are listed: Ethinyl estradiol, the synthetic estrogen used in most oral contraceptive formulations, and Levonorgestrel, a synthetic progesterone used in combined oral contraceptive pills, emergency contraception, the Mirena IUD, and progestin-only birth control pills. Levonorgestrel is considered of “specific interest.”
The concern with these chemicals is not the effects they may have on women taking them, but on the possible reproductive impact on wildlife from the excretion of these chemicals into the aquatic environment. It seems ethinyl estradiol and levonorgestrel are considered safe contraceptive drugs when taken by choice to disrupt fertility, but EDCs worthy of concern when such disruption is unintended.
How would it change our perception of hormonal contraceptives if we acknowledged them as endocrine disrupting chemicals? Would we wonder why there is no discussion of how these EDCs might contribute to the health issues considered in the report? Would we ask why hormonal contraceptive EDCs are routinely used to “treat” (meaning only to alleviate symptoms of) endometriosis, fibroids and PCOS – conditions potentially caused by other EDCs?
Another relevant concern addressed in the report is the effect of “estrogenic agents, and their role in breast cancer.” The report states there “is good experimental evidence that estrogenic chemicals with diverse features can act together to produce substantial combination effects.” I have to wonder how hormonal contraceptive EDCs fit into this mix.
Here’s something to ponder. Last week news stories reported that the incidence of advanced breast cancer among young American women, ages 25 to 39, has risen steadily since 1976. Lead researcher Rebecca Johnson was quoted as saying, “We think it is a real trend and, in fact, it seems to be accelerating.” The increase is small in relative numbers, only 850 cases in 2009, but the “trend shows no evidence for abatement.”
Researchers can’t explain the increase. Lifestyle changes, obesity, sedentary lifestyle and toxic exposure to environmental chemicals are offered as possible factors. But what about the hormonal contraceptives many women of this generation have been taking since they were 15 or 16 years old? Surely these EDCs must be considered as potentially contributing factors.