Friday, June 12, 2015

Glyphosate and Gut Bacteria

I've been wanting to write this blog for a long time, and now I'm glad I didn't until now.

There is a groundswell of outcry against the herbicide glyphosate, the stuff that has the acute toxicity as a sip of your favorite beer.  If you listen to the anti-GM activists, it causes everything from autism to Alzheimers, to allergies, to cancer, to celiac disease, and a dozen other ailments. 

Of course, none of been demonstrated experimentally.  It is easier and more fun to just make up goofy talk. 

I do get a lot of email about this lately and an article published from Natural Society (red flag here) brings one issue to the fore-- It is not toxic to humans, but it is toxic to the bacteria in the gut.

It has even become the basis of a class-action lawsuit, claiming that the manufacturers, well, one manufacturer that these goons especially don't like, did not provide a warning label on the package about toxicity to human gut bacteria.  

Matthew Phillips is an attorney that is suing Monsanto in California over this issue.  He's claiming a conspiratorial media blackout, a coordinated removal of information fromWikipedia, and other claims the unaware commonly make. 

Philips forgets one important fact -- unless you're chugging from the bottle, you're not exposed to much glyphosate. 

Just like Seneff, Smith, Huber and all of the other doomsdayers somehow forget to realize, there is somewhere between zero and next to zero residue in food.  If there's nothing there, then it can't affect you.

Of course, most of these folks are likely subscribers to homeopathy, a belief that the more dilute something becomes, the more powerful it gets, so I see why their knickers are twisted. 

What does the literature say?  There are a number of reports that describe glyphosate residues on crops.  Arregui et al. (2003) show that soybeans treated multiple times a year have between 0.1 to 1.8 mg/kg glyphosate on fresh soybeans. Duke et al., (2003) detect from 0.10 to 3 mg/kg on fresh soybeans, and the higher number is a clear outlier in the dataset. 

At these levels a likely acute lethal dose of soybeans would be more than 100,000 kg of soybeans, or 1000 x my body weight in raw soy.

Gag me with a spoon.

But what about those poor bacteria?  The math just does not work. Shehata et al. (2013) look at the effect on beneficial and pathogenic bacteria from chickens.  The results show that some bacteria are inhibited, but the thresholds for inhibition are 0.150 mg/ml.  That's about what you'd take in if you ate between 100g and 1 kg fresh soy, and concentrated it into a test tube. Imagine that diluted in the body and spread out among the entire intestine... 

At the high end of 1.8 mg/kg, if you ate a 100 g of soybeans (raw, as an processing will dilute out glyphosate even more) you'd take in 0.18 mg. Work has been done to understand the pharmacokinetics of glyphosate metabolism and excretion, and yes, it does accumulate most in the small intestine (Williams et al., 2003).  However, this is about 60% of the dose (the rest goes in urine), and that leaves the body via the feces within 72 hours. 

But are those tiny amounts likely to cause catastrophic changes in bacterial flora?  Not so much.  Of course, Natural Society authors claim, "it could demolish gut health."

To conclude, the authors of these "gut health" papers make a big leap.  Farmers use glyphosate on fields, fields contain food, food goes to the consumer, therefore consumers are eating glyphosate!  They simply lack the sophistication to understand how little is used, how little remains in crops, how little is detected in food, and how much is actually in the intestine.


I'll give them credit for one thing-- it is at least a plausible hypothesis.  Now they actually have to find some data to support their claims.  If this was true, you'd be able to find plenty of glyphosate in a dookie, and I can't say that I've seen that evidence.