Updated: Aug 25, 2022
If you go and check out the list of Potential Endocrine Disruptors from the Endocrine Disruption Exchange, you might be inclined to lock yourself in a (wooden, untreated) box wrapped in (organic) cotton wool and never come out again... (you'll find a link to the list at the bottom of this blog)
The reality is, that we are bombarded with chemicals all day, every day in every way and some of those chemicals have been shown to mess with our hormones.
There is an association between exposure to some EDCs (endocrine disrupting chemicals) and all sorts of knock on effects like miscarriage and early menopause.
So far, it's mostly just an association - which in scientific terms doesn't mean that it definitely CAUSES those problems.. just that it's associated with it.
Now if you wanted to be pedantic, you could say that there is an association between drinking water and sleeping - everyone who drinks water, goes to sleep.... but we know that drinking water won't CAUSE you to go to sleep.. in fact the two things are not even related.. so we need to be careful with our words, and how hysterical we get.... but the association between exposure to these EDCs and some of these hormonal imbalances is so strong that it cannot be ignored or passed off as coincidence.
Logic says that any chemical that can mimic your body's natural hormones, bind to the binding sites otherwise reserved for hormones like oestrogen and progesterone and testosterone - well thats gotta have an impact on how your body functions and regulates itself... So I for one am erring on the side of caution...
It is impossible to exist in this world without being exposed to endocrine disrupting chemicals (or potential endocrine disrupting chemicals)... they are literally everywhere we go, and in everything we do. The trick, as I see it, is to find ways to reduce our exposure.. by looking at the exposures we can control vs the ones we can't.
For example, we know BPA is an endocrine disruptor... so we choose plastics that are BPA free. Most plastics you buy in Australia are BPA free now, but did you know that when a plastic says it is BPA free, it is often full of BPS instead... and BPS is just as bad!
so we can go one step further, and significantly reduce our exposure to ANY sort of plastic.... and we can point blank STOP heating any plastics we have in our house (which is what causes the endocrine disrupting chemicals to be released into whatever is inside them - food in the microwave for example..)
and then we can educate ourselves on all the hidden exposures to BPA, like in the lining of tins (I'm thinking tinned tomatoes, tinned corn, tins of soup etc), the lining of take-away coffee cups, and the 'sheen' on sales receipts.. all these things are easily avoided or replaced - making a start on reducing exposure to at least one known EDC (Endocrine Disrupting Chemical).
So what is the guidance for GPs in relation to their patient's fertility? Well, Fertility rates have been declining steadily in Western Countries for years with 1 in 6 couples now needing help with fertility (1).
The reasons for this are strongly debated, but a trend to delaying starting a family, and general lifestyle factors are thought to play a major role (poor diet and lack of exercise).
The effects of environmental toxicants, including EDCs, on fertility is an increasingly debated topic, although there is now substantial evidence that they detrimentally affect reproductive capability.
There are more than 1480 EDCs found in everyday items, including food container plastics, personal care items, and food products, as well as those used in manufacturing, industrial, and agricultural processes (2-4).
Large surveys have identified that more than 95% of the general US population have measurable concentrations of EDCs in blood or urine samples (5-7)
You could argue that anything at a high enough 'dose' is toxic - but some of these chemicals have been shown to have greater impact at LOWER concentrations - this article states that the concentrations needed to show a response are in the picogram and nanogram levels - much lower than the levels of our body's own hormones.
What we don't know yet, is how good our bodies are at dealing with these compounds - whether we can detoxify them or excrete them ourselves without causing problems. Our bodies are generally pretty good at detoxifying themselves, but there is more and more evidence that shows a negative effect of EDCs on reproduction and development (3,4)
It's really hard to gather this evidence - like with any potentially harmful intervention of exposure to humans - it is unethical to conduct human randomised controlled trials that would provide us with 'evidence' and 'causality'.
Some studies have shown above average levels of several EDCs within the group of people seeking help with fertility compared to those who conceive naturally (3,4)
Having said that, finding evidence in humans is limited to investigating individual EDC effects on adult fertility, it's hard to get longitudinal assessment (assessment over a long time) and because we are exposed to so many different EDCs all the time in our everyday lives simultaneously - it's pretty hard to get a clear picture of the combined effects on fertility. Defining adverse effects and setting ‘safe’ exposure limits (if any) has been and, continues to be, problematic.
Therefore, in lieu of ‘safe’ limits, the best option is to reduce exposure or avoid EDCs where practicable, as advocated by the United Nations, the WHO and the Endocrine Society, as well as many professional healthcare associations (3,4,8).
The article summarises that it is clear that several EDCs have a direct negative effect on male and female fertility and fecundity (time to pregnancy). For Male fertility (because it's easier to access sperm than eggs - therefore easier to study sperm than eggs) there is strong evidence of negative effects on sperm motility, sperm DNA, sperm count and morphology - ie basically everything about the Sperm sample.
There seems to be only moderate evidence of negative effects on oocyte quality, implantation rate, and miscarriage rates after exposure to bisphenol A (BPA) or PCBs. But stronger evidence of a negative association with fecundity (Time To Pregnancy - TTP) is, however, apparent for PCBs and pesticides including DDE.
Importantly, they say, it should be noted that even though no definitive statement can be made about the potential harm for a number of EDCs:
This does not mean there is no associated harm
sooo... what do they recommend?? They recommend (like I do) that you find ways (that are easy and don't interrupt your life too much, or cost lots of money) to reduce your exposure to known EDCs....
Wash your fruit and veggies to rid them of any lingering pesticides or EDC-containing compounds
Avoid pre-packaged and processed food - lots of EDCs are on food packaging - especially tins. Where possible, buy fresh and cook from scratch
Never heat food in plastic or covered with plastic wrap or tin foil
Avoid drinking out of plastic bottles
Avoid handling or storing sales receipts
Read labels on personal care products and avoid ones that contain parabens
As there is now so much more evidence for the potential harmful effects of EDCs on fertility, professional societies are beginning to advise a harm reduction approach when it comes to EDC exposures.
For those receiving fertility treatment, in particular those diagnosed with unexplained infertility, a detailed lifestyle history should be reviewed, including possible occupational and general exposure to environmental toxicants, and efforts made to limit and reduce exposure to EDCs to improve fertility and general health.
Potential Endocrine Disruptors from the Endocrine Disruption Exchange
1. Inhorn, M. C. & Patrizio, P. (2015) Infertility around the globe: new thinking on gender, reproductive technologies and global movements in the 21st century. Human Reproduction Update 21, 411-426, doi:10.1093/humupd/dmv016
4. United Nations Environmental Programme & World Health Organization (2013) State of the science of endocrine disrupting chemicals- 2012. Eds. Bergman A, Heindel JJ, Jobling S, Kidd SA, Zoeller RT. United Nations Environmental Programme & World Health Organization, Geneva, Switzerland, 1-289
5. Melzer, D., Rice, N. E., Lewis, C., Henley, W. E. & Galloway, T. S. (2010) Association of urinary Bisphenol A concentration with heart disease: evidence from NHANES 2003/06. PLoS One 5, doi:10.1371/journal.pone.0008673
6. Silva, M. J. et al. (2004) Urinary levels of seven phthalate metabolites in the US population from the National Health and Nutrition Examination Survey (NHANES) 1999-2000. Environmental Health Perspectives 112, 331-338, doi:10.1289/ehp.6723
7. Tyrrell, J., Melzer, D., Henley, W., Galloway, T. S. & Osborne, N. J. (2013) Associations between socioeconomic status and environmental toxicant concentrations in adults in the USA: NHANES 2001-2010. Environment International 59, 328-335, doi:10.1016/j.envint.2013.06.017
8. The American College of Obstetricians and Gynecologists Committee on Health Care for Underserved Women & Committee and American Society for Reproductive Medicine Practice Committee (2016) Committee Opinion: Exposure to Toxic Environmental Agents. Washington D.C., USA, 1-5