The negative impact of the environment on methylation/epigenetic marking in gametes and embryos

A plea for action to protect the fertility of future generations, 17 January 2019

Abstract

Life expectancy has increased since World War II and this may be attributed to several aspects of modern lifestyles. However, now we are faced with a downturn, which seems to be the result of environmental issues. This paradigm is paralleled with a reduction in human fertility: decreased sperm quality and increased premature ovarian failure and diminished ovarian reserve syndromes.

Endocrine Disruptor Compounds (EDCs) and other toxic chemicals: herbicides, pesticides, plasticizers, to mention a few, are a rising concern in today environment. Some of these are commonly used in the domestic setting: cleaning material and cosmetics and they have a known impact on epigenesis and imprinting via perturbation of methylation processes. Pollution from Poly Aromatic Hydrocarbons (PAH), particulate matter (PM), <10 and <2.5 μm and ozone, released into the air all affect fertility. Poor food processing management is a source DNA adducts formation, impairing gametes quality. An important question to be answered is that of nanoparticles (NPs) that are present in food and which are thought to induce oxidative stress. Now is the time to take a step backwards. Global management of the environment and food production is required urgently in order to protect the fertility of future generations.

Reference.

DES and the GENES

Impact of endocrine disrupting chemicals exposure on fecundity as measured by time to pregnancy

A systematic review;, Environmental research, 2018 Dec

Abstract

BACKGROUND
Emerging scientific evidence suggests that exposure to environmental pollutants is associated with negative effects on fecundity as measured by time to pregnancy (TTP).

OBJECTIVES
To conduct a systematic review of the literature on the association between selected endocrine disrupting chemicals (EDCs), and fecundity as measured by TTP in humans. Compounds included in this review are: brominated flame retardants (BFRs) such as hexabromocyclododecane, tetrabromobiphenol A and polybrominated diphenyl ethers; organophosphates flame retardants (OPFRs); and phthalates.

METHODS
Scopus, MEDLINE via Ebscohost and EMBASE databases were searched for articles exploring the relationships between selected EDCs and fecundity as measured by time to pregnancy. We assessed the quality of included studies and evidence for causality was graded using the criteria developed by the World Cancer Research Fund.

RESULTS
14 studies of 191 full-text articles assessed for eligibility were included for qualitative synthesis. Five studies examined BFRs and 10 studies examined phthalates. Among the fourteen, one study assessed both BFRs and phthalates. There were no studies which investigated fecundity as measured by TTP on HBCD, TBBPA, or OPFRs. We recorded plausible fecundity outcomes as measured by TTP related to some of these EDCs. BFRs or phthalates increased TTP. However, results were inconsistent.

CONCLUSION
We recorded mostly weak associations between exposure to selected EDCs and fecundity. However, evidence was considered limited to conclude a causal relationship due to inconsistency of results. The health risks posed by these chemicals in exposed populations are only beginning to be recognized and prospective measurement of the environmental effects of the chemicals in large cohort studies are urgently needed to confirm these relationships and inform policies aimed at exposure prevention

Genomic imprinting disorders

Lessons on how genome, epigenome and environment interact

2019 Study Abstract

Genomic imprinting, the monoallelic and parent-of-origin-dependent expression of a subset of genes, is required for normal development, and its disruption leads to human disease.

Imprinting defects can involve isolated or multilocus epigenetic changes that may have no evident genetic cause, or imprinting disruption can be traced back to alterations of cis-acting elements or trans-acting factors that control the establishment, maintenance and erasure of germline epigenetic imprints.

Recent insights into the dynamics of the epigenome, including the effect of environmental factors, suggest that the developmental outcomes and heritability of imprinting disorders are influenced by interactions between the genome, the epigenome and the environment in germ cells and early embryos.

This review focuses on imprints that effect essentially permanent and ubiquitous changes on gene expression potential at affected loci, as opposed to tissue-specific or transient changes.

DES and the GENES

Cochrane HPV vaccine review not found to be ‘Trusted Evidence’

The Cochrane HPV vaccine review was incomplete and ignored important evidence of bias

In May 2018, the Cochrane Collaboration published its review of the human papillomavirus (HPV) vaccines. The review primarily assessed the vaccines’ effect on precursors to cervical cancer. Cochrane has high standards for its reviews; however, there were important limitations in its HPV vaccine review, which we address in this paper.

Key findings

  • The Cochrane human papillomavirus (HPV) vaccine review missed nearly half of the eligible trials
  • No included trial in the Cochrane review used a placebo comparator
  • The included HPV vaccine trials used composite surrogate outcomes for cervical cancer
  • The Cochrane review incompletely assessed serious and systemic adverse events
  • The Cochrane review did not assess HPV vaccine-related safety signals
  • Industry trial funding and other conflicts of interest
  • Cochrane’s public relations of the review were uncritical

Conclusion

Part of the Cochrane Collaboration’s motto is ‘Trusted evidence’. We do not find the Cochrane HPV vaccine review to be ‘Trusted evidence’, as it was influenced by reporting bias and biased trial designs. We believe that the Cochrane review does not meet the standards for Cochrane reviews or the needs of the citizens or healthcare providers that consult Cochrane reviews to make ‘Informed decisions’, which also is part of Cochrane’s motto. We recommend that authors of Cochrane reviews make every effort to identify all trials and their limitations and conduct reviews accordingly.

Read the author’s full paper on The BMJ.

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Révision (Cochrane) du vaccin HPV : incomplète et avec de nombreux biais ?

Rien ne justifie de recommander le vaccin Gardasil contre les papillomavirus

Cochrane – Une institution indépendante de l’industrie pharmaceutique, a récemment blanchi les vaccins recommandés pour prévenir le cancer du col de l’utérus, controversés depuis dix ans. Des voix qui contestent solidement l’efficacité de cette vaccination mettent aujourd’hui leurs données à la disposition du public et des médias.

Avec ses collègues (Dr Jean-Pierre Spinosa, gynécologue, et Serena Tinari, journaliste d’investigation), Catherine Riva considère que Cochrane devrait rétracter cette revue et tout reprendre depuis le début. Mais l’organisation est restée sourde aux doléances qu’ils lui ont adressées suite à la publication de la revue. Son refus d’entrer en matière est la goutte de trop qui les amène aujourd’hui à tout rendre public. Le 10 décembre, leur analyse critique de la revue Cochrane sur les vaccins anti-HPV était dévoilée sur le British Medical Journal  L’ensemble des données et des tableaux à l’appui de leurs conclusions ainsi que leurs six ans de correspondance avec Cochrane sont désormais en accès libre.

LisezRien ne justifie de recommander le vaccin Gardasil contre les papillomavirus” sur parismatch.

Lessons learnt on transparency, scientific process and publication ethics

The short story of a long journey to get into the public domain unpublished data, methodological flaws and bias of the Cochrane HPV vaccines review

Abstract

Cochrane meta-analyses are considered the gold standard to assess public health interventions’ benefits and risks. Cochrane reviews shall apply evidence-based medicine (EBM) methodology on the best available evidence; they shall adhere to strict ethical guidelines as authors of Cochrane reviews are supposed to not have bias, nor conflicts of interest. Our 6 years’ documented case on the Cochrane human papillomavirus (HPV) vaccines review demonstrates that Cochrane guidelines can fail. According to EBM standards, such relevant methodological and ethical flaws void Cochrane positive conclusions on HPV vaccines efficacy.

Cochrane published a review of the human papillomavirus (HPV) vaccines on 9 May 2018. On 4 June, we submitted a detailed analysis of this review as a comment via the Cochrane website.

Our comment highlights serious methodological flaws in the review:

  • (A) studies’ quality not properly assessed;

  • (B) post hoc subgroup analyses presented as randomised controlled trial results;

  • (C) reporting bias not acknowledged;

  • (D) selective reporting not taken into consideration;

  • (E) biased trial designs;

  • (F) unpublished data not included;

  • (G) conflict of interests (COI) in the authors’ group;

  • (H) n=7 studies on Gardasil included, n=18 for Cervarix—the latter not being marketed in the USA anymore.

… continue reading on The BMJ, by Catherine Riva, December 2018.

visit re-check ref hpv-vaccination.

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Treatments to Manage Weeds and Pests Without Pesticides

Pesticide Action Network Europe, 2018

Published on 4 Nov 2018, by PAN Europe

Read Alternatives Methods in Weed Management to the Use of Glyphosate and Other Herbicides, 10/2017.

Techniques to Manage Weeds and Pests Without Agrichemicals

Pesticide Action Network Europe, 2018

Published on 4 Nov 2018, by PAN Europe

Read Alternatives Methods in Weed Management to the Use of Glyphosate and Other Herbicides, 10/2017.

Techniques to Manage Weeds and Pests Without Pesticides

Pesticide Action Network Europe, 2018

Published on 4 Dec 2018, by PAN Europe

Read Alternatives Methods in Weed Management to the Use of Glyphosate and Other Herbicides, 10/2017.

Weed Management Alternative Methods

Pesticide Action Network Europe, 2016

Published on 9 Dec 2016, by PAN Europe

Read Alternatives Methods in Weed Management to the Use of Glyphosate and Other Herbicides, 10/2017.