Methylparaben in meconium and risk of maternal thyroid dysfunction, adverse birth outcomes, and Attention-Deficit Hyperactivity Disorder

[helvella]

Although it appears that endocrine disruption by environmental chemicals is being ignored, there really is a steady stream of papers.

Environ Int. 2020 Apr 10;139:105716. doi: 10.1016/j.envint.2020.105716. [Epub ahead of print]

Methylparaben in meconium and risk of maternal thyroid dysfunction, adverse birth outcomes, and Attention-Deficit Hyperactivity Disorder (ADHD).

Baker BH1, Wu H2, Laue HE3, Boivin A4, Gillet V4, Langlois MF5, Bellenger JP6, Baccarelli AA2, Takser L4.

Author information

1 Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States. Electronic address: [e-mail].

2 Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, United States.

3 Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.

4 Department of Pediatrics, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada.

5 Division of Endocrinology, Department of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada.

6 Department of Chemistry, Faculty of Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada.

Abstract

BACKGROUND:

Parabens, which are used as a preservative in foods and personal care products, are detected in nearly 100% of human urine samples. Exposure to parabens is associated with DNA damage, male infertility, and endocrine disruption in adults, but the effects of prenatal exposure are unclear. In part, this is due to inadequate assessment of exposure in maternal urine, which may only reflect maternal rather than fetal exposure. To address this gap, we examined the association of prenatal methylparaben measured in meconium with preterm birth, gestational age, birthweight, maternal thyroid hormones, and child Attention-Deficit Hyperactivity Disorder (ADHD) at 6-7 years.

DESIGN:

Data come from the GESTation and the Environment (GESTE) prospective observational pregnancy cohort in Sherbrooke, Quebec, Canada. Participants were 345 children with data on ADHD among 394 eligible pregnancies in women age ≥18 years with no known thyroid disease before pregnancy and meconium collected at delivery. Methylparaben was measured in meconium. Birthweight, gestational age, and maternal thyroid hormones at <20 weeks gestation were measured at the Centre Hospitalier Universitaire de Sherbrooke. Preterm birth was defined as vaginal birth before the 37th week of gestation. Physician diagnosis of ADHD was determined at a scheduled cohort follow-up when children were 6-7 years old or from medical records. Associations between meconium methylparaben and outcomes were estimated with logistic and linear regressions weighted on the inverse probability of exposure to account for potential confounders, including child sex, familial income, maternal education, pre-pregnancy body mass index, age, and smoking and alcohol consumption during pregnancy.

RESULTS:

Methylparaben was detected in 65 meconium samples (19%), 33 children were diagnosed with ADHD (10%), and 13 children were born preterm (4%). Meconium methylparaben was associated with preterm birth (odds ratio [OR] = 4.81; 95% CI [2.29, 10.10]), decreased gestational age (beta [β] = -0.61 weeks; 95% CI [-0.93, -0.29]) and birthweight (β = -0.12 kg; 95% CI [-0.21, -0.03]), altered maternal TSH (relative concentration [RC] = 0.76; 95% CI [0.58, 0.99]), total T3 (RC = 0.84; 95% CI [0.75, 0.96]) and total T4 (RC = 1.10; 95% CI [1.01, 1.19]), maternal hypothyroxinemia (OR = 2.50, 95% CI [1.01, 6.22]), and child ADHD at age of 6-7 (OR = 2.33, 95% CI [1.45, 3.76]). The effect of meconium methylparaben on ADHD was partially mediated by preterm birth (20% mediation) and birthweight (13% mediation).

CONCLUSIONS:

Meconium methylparaben was associated with preterm birth, decreased gestational age and birthweight, maternal thyroid hormone dysfunction, and child ADHD. Parabens are a substantial health concern if causally related to these adverse outcomes.

Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.

KEYWORDS:

Attention-Deficit Hyperactivity Disorder (ADHD); Birth outcomes; Endocrine disruption; Parabens; Prenatal exposure; Thyroid hormones

PMID: 32283359

DOI: 10.1016/j.envint.2020.105716

ncbi.nlm.nih.gov/pubmed/322...

Full article freely available here:

sciencedirect.com/science/a...

[nightingale-56]

Very interesting post helvella . It really is time all our medicines and personal hygiene items were made much more purely. Having ordered and just received Arnica Gel for bruised ribs as recommended by a Doctor with 111 yesterday, yet again I find another item with Acacia Powder (Xanthan Gum) in it. This is the worse possible thing for me. I couldn't find a list of ingredients on the advertising when I ordered it and it gave the impression it was just the Arnica in it. It is all such a minefield nowadays. Thanks for posting.

[jimh111]

This is a massive subject with thousands of papers, nearly all written by toxicologists or environmental scientists. Endocrinologists are generally unaware of endocrine disruption. An exception is the US journal 'Endocrinology' which does cover the subject.

My interest is PBDEs because they can affect thyroid hormone action whilst not altering TSH levels (and hence no obvious effects on fT3, fT4). A PubMed search 'PBDE thyroid' returns 360 papers. Many endocrine disrupting chemicals (EDCs) affect thyroid output and hence TSH. These cases will be spotted because of abnormal TFTs - although they will probably be misdiagnosed as primary hypothroidism and consequently mistreated! This is one reason why I don't approve of trying to lower the TSH cut-off for diagnosing primary hypothyroidism, the wrong form of hypothyroidism will be diagnosed.

[helvella Administrator in reply to jimh111]

I do not know why I became hypothyroid. Just started, slowly, having symptoms, and my TSH rose consistently over many months. Negative for TPO antibodies - but that was the only "investigation".

I am absolutely certain I really was hypothyroid, my FT4, when eventually they did it, was right at the bottom of range. And many symptoms resolved over the titration of levothyroxine.

While I knew of endocrine disruption, and various other possible causes, I decided the important thing was treatment rather than worrying too much about the "why?", for me. Still interesting and concerning in the wider field of everyone else.

[jimh111 in reply to helvella]

At a superficial glance it seems you had primary hyperthyroidism. Endocrine disruption is so important because cases are hidden behind normal TFTs and patients need supra-physiological doses of hormone including T3 to overcome the effects. The scale could be small or very large we just don’t know. Many disorders such as IBS, fibromyalgia and CFS/ME became very prevalent just after EDCs became common.

[TSH110 in reply to jimh111]

So you think a TSH of 10 is ok?

[jimh111 in reply to TSH110]

A TSH of 10 is around where a TSH assay becomes specific for primary hypothyroidism. Below that level you are likely to include many false positives, diagnose people who do not have hypothyroidism.

I feel hypothyroidism should be diagnosed primarily on signs and symptoms combined with the response to thyroid hormone therapy. Blood tests are useful for diagnosis and titration provided they are interpreted intelligently.

For example patients with severe hypothyroidism and a TSH of say 5.0 are unlikely to be suffering from primary hypothyroidism, I.e. a failing thyroid gland. They are hypo but there must be some other cause. If their problem is primary hypothyroidism they should recover with normal doses of levothyroxine and perhaps just a little liothyronine. Very often this doesn’t happen. The wrong treatment is targeted because the wrong form of hyperthyroidism has been diagnosed. It’s better to admit we don’t know the reason for the patient’s hypothyroidism rather than pushing for the wrong diagnosis. Trying to lower the TSH diagnostic level will in the long term make matters worse. We need to get endocrinologists to accept there are other forms of hypothyroidism that need different treatment strategies.

[TSH110 in reply to jimh111]

Would not antibody testing help at least to some extent? Screening those with a family history of it seems a good idea to me too. I have to admit I still felt pretty grim with a TSH of 5 but that was on the long painfully slow way down from 110. There was no question I was hypothyroid by that juncture (my correct diagnosis is atropic autoimmune thyroiditis). Perhaps I felt well when it first rose to 5, but I am not convinced. I didn’t feel well for decades. Given most doctors haven't a clue about symptoms or signs of hypothyroidism it’s going to take a huge sea change for them to start doing diagnosis that way now - I don’t see it happening any time soon, although I agree that is how it ought to be. I think I didn’t recover fully because liothyronine was not prescribed in my case although my blood tests indicated I had a conversion problem and should have benefited from its addition to Levothyroxine. No amount of Levothyroxine alone made me feel properly better. Liothyronine for thyroid hormone therapy does not appear to be prescribed at all where I live. I found NDT restored my health with the added bonus of completely banishing my long standing depression.

What percentage of the tests will be false negatives? What do these people actually have that is causing the elevated TSH is it these chemicals or does no one know and is giving them Levothyroxine dangerous for their health or can they recover if it’s stopped?

I hear a lot of ill people unable to get diagnosis or treatment here or told they’ll just have to wait until their TSH goes over 10, it used to be 5 not that long ago. It’s lower in other countries. I’ve read some alarming stuff about the effects of sub clinical hypothyroidism, it can’t be good for anyone.

My current understanding is 90% of thyroid disorder is autoimmune, of three main types : Hashimotos, less commonly atropic thyroiditis and Graves’ disease with varying levels of cross over according to antibody type, and with some possibility for remission in certain cases. Leaving 10% secondary (ie due pituitary disorders etc) but getting the same treatment anyway. I have a feeling there was once a third category that got lumped with secondary. Are there other kinds as well? I suppose with 38 thyroid hormones (I think diogenes mentioned it was somewhere around that number) it will prove to be a lot more complicated than current knowledge indicates.

[jimh111 in reply to TSH110]

The TSH > 10.0 mIU/L applies if the only factor looked at is TSH. For example, the European guidelines suggest a three month trial of levothyroxine if TSH is elevated above its upper limit and there are symptoms. The recommendation of a 10.0 limit is based on studies that look at improvement of e.g. cardiac markers and cruically whether patients respond to levothyroxine treatment guided by TSH! A bit of a closed loop.

My view is that if a patient has profound symptoms and their TSH is not above 10.0 they are most likely hypothyroid and will probably not respond well to levothyroxine monotherapy. I dislike arguments above where TSH should be because it keeps the emphasis on TSH which is a very poor marker (except when it is elevated above 10.0).

Statistics about how much hypothyrodism is autoimmune etc. always presume hypothyroidism is either primary or central. They ignore endocrine disruption and subtle but profound disorders such as subnormal TSH secretion which affects both thyroid hormone levels and deiodinase. It is quite possible there are more cases of hypothyroidism due to endocrine disruption than primary hypothyroidism, the cases have not been identified. The rapid increase in the number of 'functional disorders' since the introduction of endocrine disrupting chemicals suggest this is a possibility.

[helvella Administrator in reply to jimh111]

My TSH was only a little bit over reference range - but the clear plot over many months showed what was happening. And the FT4 then done confirmed that TSH was, more or less, reflecting the actual FT4 level.

Had I presented with just the one slightly over rnage TSH test, that would have been insufficient evidence - even if accompanied by an FT4 at bottom of range.

[TSH110 in reply to jimh111]

Thanks for clarifying. This is very interesting. I am sure all these chemicals that have got absolutely everywhere and are in all of us now and all the creatures of the earth and sea are a serious health concern. What help might be appropriate if they are the culprit for raised TSH results. Can the genie be put back in the bottle by banning these unhealthy chemical concoctions....oh dear I’m having a we’re all off to hell in a handcart moment

[helvella Administrator]

Just did a quick search and found that, among many others, even Lush used methylparaben in some products:

uk.lush.com/ingredients/met...

And Nivea:

nivea.co.uk/advice/skin/par...

And Boots E45 Moisturising Lotion and E45 Daily Lotion:

chemistdirect.co.uk/e45-moi...

e45.co.uk/our-products/dail...

And up to 20% of Body Shop products:

Do your products contain parabens?

Many studies have established that parabens are perfectly safe for use in cosmetics. However, some of our customers continue to express concern about their inclusion in our products. As a result, 80% of our products are paraben free so we can offer a broad choice for everyone.

In addition, we are currently in the process of removing parabens from all of our products and are aiming to be paraben free over the next few years.

If people are concerned about parabens, we have a large number of products that are paraben free. For example, our Rainforest shampoos are free of parabens, sulphates and colourants.

thebodyshop.com/en-gb/help/...

I could spend the rest of the year telling you what contains methylparabens. Because so many products do.

[TSH110 in reply to helvella]

Oh dear Cetraben even has it in the name... do you think olive oil would be as efficacious?

[helvella Administrator in reply to TSH110]

Are you really sure?

What I could see was this:

Cetranben Cream [copied and pasted - including their typo!]

Some important information about the ingredients: This product contains cetostearyl alcohol which may cause local skin reactions.

Contains: white soft paraffin 13.2% w/w, light liquid paraffin 10.5% w/w, emulsifying wax (SLS free), cetostearyl alcohol, glycerol, phenoxyethanol, citric acid monohydrate, trisodium citrate dihydrate, purified water.

boots.com/cetraben-cream-50...

But there are several products in the range.

[TSH110 in reply to helvella]

I just jumped to conclusions cos it ended in ben! It is very kind of you to have checked the ingredients and disassuage me of my erroneous and unfounded assumption. I have the complete collection of their products but the cream is the one I use mostly. Great I can carry on using it to keep my skin from resembling parchment and control the annoying itching. Olive oil does not absorb as readily and would give me spots I am sure. Old but still vain 🤣😄🤣

[helvella Administrator in reply to TSH110]

Don't worry - I agree the name very much leads us to think as you did.

[tattybogle]

I think i remember finding "endocrine disrupting chemicals" among the list of things that can cause unreliable results on TSH tests, when i was looking up what drugs could give incorrectly high or low TSH results. I remember looking up what they were and thinking "oh ....virtually everything then!" Could be mistaken, was a while ago.

[jimh111 in reply to tattybogle]

I haven't seen this but if they are suggesting EDCs cause unreliable TSH assays they are giving the wrong impression. It is highly any EDC would interfere with the assay as TSHs are very large molecules (plura intended, TSH is a group of molecules). Far more likely is that an EDC is affecting TSH levels. This could erroneously lead to harmless elevated TSH but far more likely is that TSH is elevated because thyroid hormone levels or activity is impacted.

[tattybogle in reply to jimh111]

Thanks for the clarity Jimh111, If i ever find it again in my random filing system, i'll read it more carefully.

Tat .

Edit. As jim said .. i was wrong ,EDCs don't interfere with the assay , sorry.

That was Human Anti Mouse Antibodies! ...... still don't know wtf they are.