A scientific review of numerous studies suggests that diquat, a herbicide permitted in the United States, attacks gut bacteria with damage to the liver, kidneys and lungs.
Diquat, a herbicide banned in the European Union but still widely used in the United States, can damage the gut and can also trigger a harmful chain reaction in other organs, particularly the liver, kidneys and lungs: this is revealed by a review of more than one hundred studies published last May in Frontiers in Pharmacology.
The herbicide has traditionally been studied for its toxic effects on the liver and kidneys. However, this review suggests that the gut is a key target for its harmful effects. The analysis demonstrates that diquat weakens the intestinal barrier by neutralising beneficial bacteria, interferes with nutrient absorption and triggers chronic inflammation. This weakening of the microbiota can allow toxins and pathogens to enter the bloodstream, causing damage to other organs and making the toxicity of diquat more widespread and dangerous than previously thought.
Diquat can destroy the membranes of kidney cells and interfere with cellular signalling. The effects on the liver are similar, and the ingredient causes the production of proteins that inflame the organ. The substance appears to attack the lungs by triggering inflammation that damages the organ's tissues. More broadly, the inflammation caused by diquat can lead to multi-organ dysfunction syndrome, a scenario in which organ systems begin to fail.
Diquat is banned in the United Kingdom, the European Union, China and other countries, but is widely used in the United States. The chemical multinational Bayer has introduced it into its Roundup product as a replacement for glyphosate, but according to the latest scientific data, diquat is far worse than the latter.
An analysis of EPA data — the United States Environmental Protection Agency — conducted in October by the non-profit organisation Friends of the Earth found that "on the fiftieth anniversary of its commercialisation, Roundup sold to consumers is more toxic than ever". Bayer committed to removing glyphosate from Roundup-based products sold to US consumers (which do not include Roundup for agricultural or professional use) from 2023, in response to tens of thousands of lawsuits linking the herbicide to non-Hodgkin's lymphoma.
The organisation however discovered that Bayer has replaced glyphosate with combinations of four chemicals, two of which are banned in the European Union. "The new Roundup formulations are on average 45 times more toxic to human health following chronic long-term exposure. They also present significantly greater risks to the environment. Furthermore, we found that Bayer has not removed glyphosate from all Roundup products intended for US consumers."
According to Friends of the Earth, diquat is 200 times more toxic on a chronic level than glyphosate, and the organisation stresses that although the new active ingredients are listed on the labels of Roundup-based products, as required by law, there is no wording warning consumers of the greater risks they entail. The organisation believes that all Roundup-based products should be withdrawn from sale, and that other hazardous pesticides should be gradually phased out while increasing the supply of organic products and other safer options.