No testing for glyphosate

May 2015
Pesticide spraying. CC photo by Will Fuller on Flickr
Just when the world's most-used weedkiller, glyphosate (which used to be "safe-as-salt") has been reclassified as a 'probable carcinogen' [1], the UK government has decided to wash its hands of testing for pesticide residues in food.

Food and Chemical Toxicology's new board

May 2015

In January this year, science journal Food and Chemical Toxicology (FCT) quietly re-organised its editorial board.

This wouldn't be remarkable except for the reputation the journal has earned itself for manipulating the rules of scientific publication: including losing its grip on the peer-review process, bowing to the industry, unethical treatment of its authors, inventing spurious criteria for 'acceptable' science, and creating a special-purpose novel position on its editorial board to achieve the latter (see below).

FCT's new editor is José Domingo who has published a series of very balanced reviews of the scientific evidence on GM food safety.

America creating agri-problems for itself

May 2015
Corn rootworm. Photo from Wiki Commons
In the cold light of the GM day, American farmers and regulators are being forced to recognise they've created a couple of problems for themselves.

Corn rootworm ranks amongst the most expensive threats to US maize farmers. The invention of a GM crop which generates its own 'Bt' insecticide against the rootworm has been a great boon.

However, bolstered by biotech enthusiasm to sell as much as possible of its product, farmers' enthusiasm for reduced post-planting workload and costs, government enthusiasm for incentives to grow maize, and limited availability of alternative seeds, US agriculture has been channelled into planting the same Bt crop year-on-year.

And the rootworm have, inevitably, evolved resistance to that Bt toxin.

Aromatase assumptions

May 2015

An oft-quoted justification for the 'self-evident' safety of glyphosate herbicide is that it interferes with a plant-specific enzyme and therefore won't have any effects on humans.

Glyphosate is widely sprayed on GM crops, most of which have been designed to survive and accumulate it. The weeds around them die because 'aromatase', an enzyme vital to plant protein production, is blocked by the herbicide.

Aromatase enzyme induces 'aromatisation' which means a ring of carbon atoms is formed to produce a new biochemical.

In plants, aromatase acts on amino acids (the building blocks of proteins) to form a class of 'aromatic' amino acids only produced by plants. Animals need aromatic amino acids to build proteins too, but must consume plants (or other animals which have consumed plants) to get them.

The human body, however, also has enzymes with aromatase action (they form a carbon ring). Human aromatase is nothing to do with amino acids or proteins, but acts on the male sex hormone, androgen, to convert it to the female sex hormone, oestrogen. Because our tissues need a precise androgen:oestrogen balance at just the right time for healthy development, most human tissues generate their own specific variant of aromatase.

Glyphosate carcinogen reactions

May 2015
The reclassification of glyphosate herbicide* as a "probable carcinogen" by the World Health Organisation Cancer Agency (IARC) predictably kick-started a well-oiled damage-limitation machine.

*Glyphosate is the active ingredient of herbicidal formulations such as 'Roundup' which is sprayed on, and accumulated by, most GM crops. It is a contaminant of animal feed and has been found in many foods.

An immediate statement was issued by the 'glyphosate Task Force' (GTF) making disparaging comments about the IARC and repeating five times in eight short paragraphs that years of reviews by regulatory authorities have found no problems with the herbicide. The GTF is a consortium of companies specifically formed "to renew the European glyphosate registration". Its member companies include Monsanto, DowAgrichemicals and Syngenta, whose business and reputation could be catastrophically damaged if the glyphosate loses it's 'safe-as-salt' image.

Three days later, Monsanto, the major manufacturer of Roundup and producer of Roundup-resistant GM crops, issued a similar statement, pouring scorn on the IARC and repeating eight times in twelve short paragraphs that regulatory reviews around the world have found no problems with the herbicide.

Glyphosate is a probable carcinogen

May 2015

As part of its remit to re-evaluate the carcinogenic potential of agri-chemicals, the International Agency for Research on Cancer (IARC) has just produced its report on glyphosate herbicide.

The outcome is that gyphosate is now classified by the World Health Organisation (WHO) body as "probably carcinogenic to humans". This is one step short of "carcinogenic", a category to which very few chemicals as assigned.

Accepted scientific conclusions require that several different lines of evidence are investigated, all of which support the conclusion drawn. Accordingly, the IARC routinely examines data from three types of study:

Glyphosate disrupts oestrogen-linked genes

April 2015

The bases for claims that glyphosate herbicide is safe in food are that it acts on a biological process that is only present in plants, not animals, and that any glyphosate absorbed during digestion passes through the body unchanged.

Both of these are true.

However, the present-day, massive, volumes of glyphosate sprayed on, and absorbed by, most GM commodity crops has focused attention on whether the assumptions about glyphosate's 'inert' nature in animals tell the whole story.