Herbicide health risks underestimated

Widely used herbicide glyphosate (Roundup) may pose more severe health risks than previously assumed, according to new study at Aarhus University

A first-of-its-kind study by Aarhus University warns that glyphosate, Denmark’s (and the world’s) best-selling herbicide, can have dangerous side-effects that have not been sufficiently investigated.

Glyphosate is the most widely used herbicide chemical in the world and the active ingredient in Monsanto’s popular weed control agent Roundup.

It is often used in conjunction with crops genetically modified to be resistant to glyphosate – such as soya bean, maize, cotton, and canola – so that only unwanted weeds are destroyed.  

Indirect risks understudied
Numerous studies have examined the direct health effects of both GM crops and glyphosate in many different contexts. However, the present study is the first one to focus on the indirect impacts of GM crops sprayed with glyphosate on the animals that eat them.

The Danish Food & Drug Administration has asked the DCA (National Center for Food and Agriculture at Aarhus University) to assess whether there is a need for further investigation of the possible adverse effects of glyphosate-treated, GM crops.

The request was motivated by the observation that Danish farmers saw vast improvements in the health of their animals after switching to non-GM feed.

Results are not reassuring
Glyphosate acts on microorganisms in the gastrointestinal tract of the animals, and it can also alter the uptake of important minerals from the diet, as the present study confirms.

It also appears that pathogenic (disease-causing) bacteria are less inhibited by glyphosate than non- pathogenic bacteria.

So even when the amounts of residue of the substance in both Danish and imported feed comply with the official limits, it does not prove the feed is harmless, warns Martin Tang Sørensen, the head of the research team.

That is because the limits do not take into account such indirect influences of microorganisms in the gut of the animal, or their mineral absorption.

Not something to take lightly
Further studies are needed to clarify the risk that glyphosate residues found in both imported and home-grown feed poses to livestock. 

"The amount of GM food is so great that one should not ignore the indirect effects," Sørensen told Ingeniøren.

Glyphosate has been the subject of much debate and criticism among environmental protection groups for many years.