Research Check: do we need to worry about glyphosate in our beer and wine?



File 20190307 100787 1qzaux0.jpg?ixlib=rb 1.1
Research out of the US tested different varieties of beer and wine for the presence of glyphosate – but there’s lots to consider when interpreting the findings.
From shutterstock.com

Ian Musgrave, University of Adelaide

Glyphosate is back in the news again. The common weed killer, which has previously attracted controversy for its possible link to cancer, has been found in beer and wine.

Researchers in the US tested 15 different types of beer and five different types of wine, finding traces of the pesticide in 19 out of the 20 beverages.

So how much should we be worried? Hint: not at all. The amount detected was well below a level which could cause harm. And there are insufficient details in the methods section to feel confident about the results.




Read more:
Stop worrying and trust the evidence: it’s very unlikely Roundup causes cancer


How was this study conducted?

One of the first things I do when evaluating a piece of research is to check the methods – so how the researchers went about collecting the data. What I found didn’t fill me with confidence.

The authors say they set up their experiment based on a technique called a mass spectroscopy method. This methodology has been used to measure the quantities of glyphosate in milk (but not alcoholic drinks). Mass spectroscopy is a very sensitive and specific method, and the authors quote the concentrations that can be reliably detected in milk with this approach.

But the method they actually used is called enzyme linked immunosorbent assay (ELISA). Importantly, you can’t use the concentrations that can be reliably detected with the mass spectroscopy to describe ELISA sensitivity. They’re not compatible.

Glyphosate is the pesticide which makes up many weed killers.
From shutterstock.com

ELISA is sensitive, but typically not as sensitive as mass spectroscopy, which uses an entirely different physical method to measure glyphosate.

ELISA also has issues of cross contamination. Biological samples for glyphosate measurement, whether ELISA or mass spectroscopy, need careful sample preparation to avoid cross-reaction with any other materials in the sample such as the common amino acid glycine, which looks quite similar to glyphosate and is present in much higher quantities. But the authors didn’t give any detail about the sample preparation used.

These issues make it difficult to be confident in the results.

We’ve seen this before with claims of detection of glyphosate in breast milk, which could not be duplicated. So given the lack of detail around the methodologies used, we should be cautious about taking these figures at face value.

What did they find?

For the sake of argument, let’s accept the researchers’ values and take a look at what they mean.

The highest level of glyphosate they measured was 51.4 parts per billion in one wine (in most of the beverages they found much less). That’s equivalent to 0.0514 miligrams per litre (mg/L).

The authors cite California’s Office of Environmental Health Hazard’s proposed “No Significant Risk Level” for glyphosate consumption of 0.02 mg/kg body weight/day. The limits are based on body weight, so a heavier person can be exposed to more than a person who weighs less, taking into account body volume and metabolism.

This is much lower than the EU Food Safety Authorities’ and Australia’s regulatory allowable daily intake of 0.3 mg/kg body weight/day.

But again, for argument’s sake, let’s use the Californian proposed limits and look at the wine in which the researchers measured the highest amount of glyphosate. With those limits, an average Australian male weighing 86kg would need to drink 33 litres of this wine every day to reach the risk threshold. A 60kg person would need to drink 23 litres of this wine each day.




Read more:
Drink, drank, drunk: what happens when we drink alcohol in four short videos


If you’re drinking 33 litres of wine a day you have much, much bigger problems than glyphosate.

Alcohol is a class 1 carcinogen. Those levels of alcohol consumption would give you a five times greater risk of head, neck and oesophageal cancer (and an increased risk of other cancers). The risk of glyphosate causing cancer is nowhere near these levels. The irony is palpable.

This isn’t even taking into account the likelihood of dying of alcohol poisoning by drinking at this level – which will get you well before any cancer.

And that’s using the highly conservative Californian limits. Using the internationally accepted limits, an average adult male would have to drink over 1,000 litres of wine a day to reach any level of risk.

So how should we interpret the results?

The report does not contain a balanced representation of the risks of glyphosate.

They cite the International Agency for Research on Cancer’s finding of glyphosate as class 2 (probably) carcinogenic (alcohol is class 1, a known carcinogen).

But they don’t mention the European Food Safety authority finding that glyphosate posed no risk of cancer, or the WHO Joint Meeting on Pesticide Residues report showing no significant cancer risk to consumers under normal exposure.

They cite a paper on glyphosate supposedly increasing the rate of breast cancer cell growth, but not the papers that find no such thing.

They don’t cite the most important study of human exposure, the Agricultural Health Study which is the largest and longest study of the effect of glyphosate use. This study found no significant increase in cancer in highly exposed users.




Read more:
Research Check: can even moderate drinking cause brain damage?


The “report” claiming that there is glyphosate in wine and beer provides inadequate information to judge the accuracy of the claimed detection, and does not put the findings in context of exposure and risk.

Even taking their reported levels at face value, the risk from alcohol consumption vastly outweighs any theoretical risk from glyphosate. Their discussion does not fairly consider the evidence and is weighted towards casting doubt over the safety of glyphosate.

So you may enjoy your beer and wine (in moderation), without fear of glyphosate.

Blind peer review

This is a fair and accurate assessment of the study and its findings. That said, it is prudent for the scientific community to remain attentive to changes within the food supply and issues of potential risk to public health. Considering the increasing use of glyphosate by the food industry, we need continued diligence in this area. – Ben Desbrow


Research Checks interrogate newly published studies and how they’re reported in the media. The analysis is undertaken by one or more academics not involved with the study, and reviewed by another, to make sure it’s accurate.The Conversation

Ian Musgrave, Senior lecturer in Pharmacology, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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New research suggests common herbicides are linked to antibiotic resistance



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New Zealand researchers have found that the active ingredients in commonly-used weed killers like Round-up and Kamba can cause bacteria to become less susceptible to antibiotics.
from http://www.shutterstock.com, CC BY-ND

Jack Heinemann

Antibiotics are losing their ability to kill bacteria.

One of the main reasons for the rise in antibiotic resistance is the improper use of antibiotics, but our latest research shows that the ingredients in commonly-used weed killers like Round-up and Kamba can also cause bacteria to become less susceptible to antibiotics.

Herbicides induce gene activity

Already, about 700,000 deaths are attributable each year to infections by drug-resistant bacteria. A recent report projected that by 2050, 10 million people a year will die from previously treatable bacterial infections, with a cumulative cost to the world economy of $US100 trillion.

The bacteria we study are potential human pathogens. Seventy years ago pathogens were uniformly susceptible to antibiotics used in medicine and agriculture. That has changed. Now some are resistant to all but one or two remaining antibiotics. Some strains are resistant to all.


Read more: Drug resistance: how we keep track of whether antibiotics are being used responsibly


When bacteria were exposed to commercial herbicide formulations based
on 2,4-D, dicamba or glyphosate, the lethal concentration of various antibiotics
changed. Often it took more antibiotic to kill them, but sometimes it took less.
We showed that one effect of the herbicides was to induce certain genes that they all carry, but don’t always use.

These genes are part of the so-called “adaptive response”. The main elements of this response are proteins that “pump” toxins out of the cell, keeping intracellular concentrations sublethal. We knew this because the addition of a chemical inhibitor of the pumps eliminated the protective effect of the herbicide.

In our latest work, we tested this by using gene “knockout” bacteria, which had been engineered to lose just one pump gene. We found that most of the effect of the herbicide was explained by these pumps.

Reduced antibiotic use may not fix the problem

For decades we have put our faith in inventing new antibiotics above the wisdom
of preserving the effectiveness of existing ones. We have applied the same invention incentives to the commercialisation of antibiotics as those used with mobile phones. Those incentives maximise the rate of product sales. They have saturated the market with phones, and they saturate the earth with antibiotic resistant bacteria.

Improper use of antibiotics is a powerful driver of the widespread resistance.
Knowing this naturally leads to the hypothesis that proper and lower use will make the world right again. Unfortunately, the science is not fully on the side of that hypothesis.

Studies following rates of resistance do generally find a decrease in resistance to specific drugs when their use is banned or decreased. However, the effect is not a restoration of a pre-antibiotic susceptibility, characterised by multi-year effectiveness of the antibiotic. Instead, resistance returns rapidly when the drug is used again.

This tells us that once resistance has stablised in populations of bacteria, suspended use may change the ratio of resistant to susceptible but it does not eliminate resistant types. Very small numbers of resistant bacteria can undermine the antibiotic when it is used again.

Herbicides and other pollutants mimic antibiotics

What keeps these resistant minorities around? Recall that bacteria are very
small, but there are lots of them; you carry 100 trillion of them. They are also found deep underground to high up in the atmosphere.

Because antibiotics are so powerful, they eliminate bacteria that are susceptible and leave the few resistant ones to repopulate. Having done so, we now have lots of bacteria, and lots of resistance genes, to get rid of, and that takes a lot of time.

As our work suggests, the story is even more complicated. We are inclined to think of antibiotics as medicine and agrichemicals, hand soaps, bug sprays and preservatives as different. Bacteria don’t do this. To them, they are all toxic.

Some are really toxic (antibiotics) and some not so much (herbicides). Bacteria are among the longest lived organisms on earth. Nearly four billion years of survival has taught them how to deal with toxins.

Pesticides as antibiotic vaccines

Our hypothesis is that herbicides immunise the bacteria from more toxic
toxins like antibiotics. Since all bacteria have these protections, the use of widely used products to which they are exposed is particularly problematic. So these products, among others, might keep bacteria ready for antibiotics whether or not we are using them.

We found that both the purified active ingredients and potential inert ingredients in weed killers caused a change in antibiotic response. Those inert ingredients are also found in processed foods and common household products. Resistance was caused below legally allowed food concentrations.

What does this all mean? Well for starters we may have to think more carefully about how to regulate chemical commerce. With approximately eight million manufactured chemicals in commerce, 140,000 new since 1950, and limited knowledge of their combination effects and breakdown products, this won’t be easy.

The ConversationBut neither is it easy to watch someone die from an infection we lost the power to cure.

Jack Heinemann, Professor of Molecular Biology and Genetics

This article was originally published on The Conversation. Read the original article.

Herbicide: RoundUp & Amphibians


The link below is to an article reporting on how RoundUp is altering the morphology of some tadpoles.

For more, visit:
http://www.matternetwork.com/2012/4/weed-killer-can-alter-shape.cfm