GM maize – a cautionary tale

In a globalised food system the story of white maize flour potentially contaminated with a nonfood variety of GM maize in the US shows why clear point-of-sale labelling is important in the UK.

March 3, 2017 by Pat Thomas

Photo: Bigstock

Occasionally interesting stories come together that give us a glimpse of the bigger picture of GMO contamination in our food.

This week two stories – both about genetically modified maize – have done just that.

Our supporters frequently write to us to let us know about their interactions with supermarkets regarding GM ingredients. Recently, one has been in an ongoing dialogue with Waitrose over P.A.N. Harina de Maiz Blanco, a brand of white maize flour which the supermarket sells online.

The product, which is sold by other food retailers in the UK as well, is labelled as containing genetically modified, and any consumer buying it in a store can see this.

Our supporter’s concern was that online shoppers were not being given easy to understand information because Waitrose did not indicate the GM origins of the maize flour under the heading ‘ingredients’ on its webpage. Instead the GMO content was listed on a side panel, under the category of ‘additives’.

Waitrose does this because this is how the product manufacturer lists it as well (and indeed Tesco’s online store also lists the GM content this way; Amazon on the other hand, illegally, doesn’t include the GMO information at all on its online grocery page).

It is unclear whether calling the maize flour an ‘additive’ is a mistake of language or something else. But there are potential consequences of the lack of clarity.

Ingredients versus additives

People’s perceptions of ‘additives’, for instance, might lead them to believe that there’s only a small amount of something in the products and even if it is genetically modified there’s probably not enough to be concerned about.

In fact, many of us may be eating GM additives without knowing it. Under European Law genetically modified additives and processing ingredients (for instance soya lecithin) do not need to be labelled as such.

According to the Food Standards Agency, an additive is: “any substance not normally consumed as a food in itself and not normally used as a characteristic ingredient of food, whether or not it has nutritive value, the intentional addition of which to food for a technological purpose in the manufacture, processing, preparation, treatment, packaging, transport or storage of such food results, or may be reasonably expected to result, in it or its by-products becoming directly or indirectly a component of such foods”.

Clearly this does not apply to a maize flour in which maize is the only ingredient.

Meeting everyone’s needs?

P.A.N. Harina de Maiz Blanco comes from Colombia which, although a producer of non-GM white maize, also imports a considerable amount from USA. As a result it is likely that this maize flour is a mix of both GMO and non-GMO maize in varying proportions.

In correspondence with our supporter the Waitrose Case Manager notes that:

“…the labelling of the P.A.N. Harina de Maiz Blanco is in keeping with the relevant food legislation.  In addition to this, we’re limited in how we present this product on our website and on our shelves – decisions on presentation are, to a certain extent, made in accordance with both parties [sic] needs.”

Which two parties he’s referring to is unclear, and indeed when it comes to food there are at least three parties whose needs must be considered: the consumer, the retailer and the manufacturer.

What is more, compliance with legislation has never been an indication that something is either safe or in the public interest.

We are often told by frustrated supporters that supermarket customer services departments are quick with polite reassurance that own brand foods are GM free. This may or may not be true depending on whether you count the GM-fed meat which accounts for 80% of all meat sold in the UK and the levels of unlabelled GM additives that go into prepared foods.

But even if it is true, own brands account for only half of what our supermarkets sell. Ingredients in the other 50% of products are beyond the retailers’ control.

Waitrose, which has recently committed to sourcing non-GM feed by 2020, has recognised this error and promised to amend it. However, at the time of writing, the information about the GM maize has simply moved from ‘additives’ to a new heading of “other information” at the side of the page. We would certainly agree with our supporter who continues to insist that the information should be identified under heading of ‘ingredients’.

Contaminated white maize

In the Americas, particularly in South and Central America (but also in countries like Spain and Portugal), maize flour is widely consumed as part of traditional diets in the form of tortillas as well being used as a dough (masa) for traditional tamales, antojitos and gorditas amongst other foods.

So why this small skirmish between customer and supermarket in a country like the UK – which still regards tortillas as ‘exotic’ – important?

A second story from our friends at the Non-GMO Report in the US shows us why.

They report that Syngenta’s Enogen, a genetically modified corn grown for ethanol production, has contaminated non-GMO white corn grown in Nebraska that is used to make flour for tortillas and other products.

Enogen GMO corn can contaminate food corn through cross pollination in the field or improper segregation during grain handling. White maize flour, supposedly made from non-GMO sources, has tested positive for Enogen contamination.

Farmers whose white corn crops are GMO-contaminated face market rejection and lost income, and are forced to sell their corn to a cheaper market such as those for animal feed or, ironically, ethanol.

‘Bad masa’

But it’s potential effects on those who eat the contaminated maize that goes so often unremarked.

We now know that GM maize is not the same as non-GM maize. The notion that the two are ‘substantially equivalent’ was knocked aside with a recent and important study which found that the process of genetic modification substantially raised levels of toxins in the plant.

But levels and types of other components, such as starches and sugars can also vary between GM and non-GM maize and especially between maize grown for food and maize grown for fuel.

Enogen maize is genetically engineered with an enzyme that quickly breaks starches down into sugars; useful if you are making biofuels – not so good if you need the kind of hard starches normally found in white corn in order to make firm tortillas, doughs and corn chips.

In California in December 2016 a large shipment of maize flour caused several problems amongst the Latino community in Downey.

Customers complained that tamales they made from the ’bad masa’ – a Christmas tradition for Hispanic families – were gelatinous and easily fell apart, and some people even fell ill after eating the maize.

The problem was traced to a shipment of 120,000 pounds of white corn delivered to Amapola market in Downey right before Christmas.

Though it’s not confirmed that the Enogen maize contaminated this batch of maize flour, the event, according to reports, echoes those of the summer of 2016, again in California, when a batch of maize flour caused similar problems and also tested positive for Enogen maize.

Concerned about GMOs in the UK foodchain - take this survey t

Concerned about GMOs in the UK foodchain? Shout about it by taking this quick survey:

Memories of StarLink

These episodes, in turn, are reminiscent of the debacle with a variety of GM corn called StarLink, which, in the early 2000s was approved for animal feed only – but which nevertheless found its way into over 300 food products.

Star Link was eventually pulled off the market due to concerns that it might cause allergic reactions, but as recently at 2013 it was still being found in US food.

It also has a flavour of the recent issues with Soylent – the meal substitute ‘proudly made with GMOs’ which had to withdraw several products from the market in 2016 when customers began to fall ill.

In countries like America, many consumers are convinced that eating GMOs is not safe, that it can and maybe even is, resulting in illness that is under-reported and largely under-investigated.

The correspondence we’ve seen over the years suggests that supermarket customer service departments are often polite but just as often not very well-informed or helpful in dealing with GMO enquiries.

Clear information required

The story the ‘bad masa’ – especially should it turn out to be the source of human illness – is a cautionary tale however. All GMO products should be clearly labelled at every point of sale (including online). Not to do so is to invite problems down the line, as more and more GMO products invade our shops.

The UK government wants us all to grow and eat more GMOs and this brings with it responsibilities both for what we know about GMOs – and especially for what we don’t yet know.

More and more GM foods that we consume directly are being approved. In the US staple foods such as a non-browning Arctic apple is on the market; three new varieties of GM potatoes have just been authorised and of course there is GM salmon.

Testing the safety of GM foods that are consumed directly or even indirectly BEFORE people start consuming them isn’t a redundant or unnecessary step. It is an absolute necessity to protect us from any harm which, research suggests, might be real and potentially devastating.

Labelling as a bare minimum requirement isn’t just a ’nice to have’, it’s not a concession to mollify a vocal minority. It is the will of the majority and for good reason: because they simply do not trust the safety of GM foods – likely with good reason.


Like what we're doing? Help us do more!
Let your MP know

You can find your MP and get in touch directly by visiting

Beyond false promises. Beyond failed technology. Beyond corporate control.
The time has come to move Beyond GM.

About this site::
GM Free Me is a Beyond GM initiative. Submitting your photo to this site is a vote for a safer, healthier more sustainable food system, for the health of our plants, animals and soil, for the independence and future security of our farmers. Thank you for speaking up.    Read more...