Glyphosate herbicde causes multiple cancers

Fact-checked – 4 min read

A major international long-term study just published (1), conducted over two years, has found that prenatal exposure to glyphosate, the world’s most widely used herbicide in crops, and its commercial formulations cause six types of cancer in rat, even at doses considered safe by regulators in Canada, United State and the EU. Researchers observed significantly increased rates of both benign and malignant tumours across numerous organs, including liver, thyroid, ovaries, kidneys, pancreas, mammary glands, and nervous system.

Particularly concerning was the spike in aggressive cancers like leukemia which are rare in young rats, equivalent to cancers in young human adults. This is especially noteworthy, as previous human studies have showed an increased risk of non-Hodgkin lymphoma form glyphosate exposure. The International Agency for Research on Cancer, which is part of the World Health Organization, classifies glyphosate as a Group 2A carcinogen, ‘probably Carcinogenic to Humans’ (2).

The relevance of these findings is that a large part of cereal grains, fruits and vegetables in Gibraltar originates from Spain, the second-largest pesticide user in the EU. Glyphosate is extensively used in Spanish agriculture in cereal and legume crops (3), highlighting the importance of choosing organic varieties, especially during pregnancy and children who regularly consume cereals.

For context, a 2018 report by the Environmental Working Group (EWG) in the US, found that Glyphosate was found in all 28 samples of different children’s cereals, oatmeal and snack bars consumed in the UK contained alarmingly high levels Glyphosate (4). The cereal products tested were:

– Kellogg’s no added sugar granola with apricot and pumpkin seeds
– Quaker oat So simple original microwaveable oats
– Weetabix oatibix 100% wholegrain oats
– Nestle Multigrain Cheerios.

Results showed that the highest total glyphosate levels were found in the Quaker Oats (~499.9 ng per gram) and the lowest in Nestle Multigrain Cheerios (~137.29 ng per grams), produced using a mixture of oats, wheat, barley, corn and rice ingredients frequently exposed to glyphosate. In the EU pesticide residues are expressed as mg per kg, whilst in the US they are expressed as parts per billion, with 1 ppb equivalent to 1 nanogram (ng) per gram. Thus the Quaker Oats contained 499ppb, a level in line with what was found in several of the oat-based cereals in the US EWG survey.

For context, these levels are considered safe by the UK and European authorities and that in all likelihood many oat cereals in the UK would have measurable levels of glyphosate in them. It is also very possible current guidelines may be under-estimating risk and thresholds should be reevaluated in line with emerging evidence. The maximum permitted glyphosate residue level in European cereals varies by crop. For oats (as well as barley and sorghum) it is higher than for other cereals; currently 20mg per kg, or 20,000 ppb. However, when considering the problem of glyphosate contamination, it is important to distinguish between the concentration in a single product sample, and how much a person would consume over a day, i.e (cumulative load), with the concentration multiplied by the grams in a serving.

Hence, the more you eat of a product, or a daily combination of contaminated products, the more residues you will likely be consuming, which could dramatically increase cancer risks. By contrast, previous studies in children and adults have found significant and rapid reductions in urinary glyphosate levels within three days of switching to an organic diet (5).

The take-home message here is to highlight the rationale for choosing organic crops to reduce risk of various cancers, and stop obsessing with macros and start considering your chemical exposures to improve long-term health outcomes.

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