Thanks!

I'm not completely sold on the lithium hypothesis, either. But I find their arguments for some kind of environmental contaminant compelling, especially for the ways in which they refute some of the other major hypotheses for the increase in body weights (e.g. food variety, processed food, etc)

Note that the SMTM folks recently published an article responding to the TDS data referred to by "It's Probably Not Lithium": https://slimemoldtimemold.com/2022/07/05/total-diet-studies-...

This is... not promising.

Someone would write like this if they don't know anything about instrumental analysis and are just guessing as a result.

As an example, they don't seem to even understand that wet and dry weights are substantivel different measures, and speak as though Magalhães et al. (1990) is measuring wet weight; it is measuring dry weight.

I'm supportive of autodidactic study and outsider research, but this is, frankly, a mess. They should unweight their priors considerably and bring in some chemists.

Note: I am the author of "It's Probably Not Lithium."

That SMTM post only addresses 5 of the ~17 studies about food lithium concentration that I mentioned in my post. It ignores several studies that did not use ICP-MS to measure lithium and found very low concentrations of it in food.

Moreover, as samatman mentioned, the post doesn't seem to understand that wet and dry weights are substantively different measures, and cites Magalhães et al. (1990) and Hullin, Kapel, and Drinkall (1969) as if they were reporting wet weight measurements of lithium, when they're reporting dry weight measurements. This makes a huge difference, because watercress (measured in Magalhães et al. (1990)) and lettuce (measured in Hullin, Kapel, and Drinkall (1969)) are both over 90% water by weight.

So that post is largely just based on cherry-picking and misrepresentation of studies.

Moreover, as far as I could tell, only *two* of their sources *actually attempt to estimate dietary lithium intake*, whereas almost all of my ~17 sources do. This is important because the SMTM post references a lot of studies that are not available on the internet, so we don't know whether they reported lithium concentration in dry or wet weight of food. Moreover, one of those sources based its estimation on hair lithium concentration rather than actual food measurements, using a regression model whose accuracy at low levels of dietary intake is unknown.

The vast majority of studies that actually attempt to estimate dietary lithium intake based on lithium concentration in food estimate it to be lower than 100 mcg/day, regardless of methodology. The only exceptions I am aware of are two studies from Manfred Anke.

We now have FDA-approved GLP-1 receptor agonists like Semaglutide that produce sustained weight loss of a magnitude similar to the weight gain discussed in that article. So the idea that something similar could be messing with this or a similar pathway hardly seems shocking to me, even if lithium perhaps isn’t the culprit.

(As an aside: we’ve also learned that proteins produced by certain gut bacteria have a similar effect on the same pathway, so it’s not crazy to imagine that gut dysbiosis could have an effect on weight gain. https://www.nature.com/articles/s41564-021-00880-5)

I wonder if PCBs play a part in it. I was reading that thanks to Monsanto pushing PCBs like they are candy has resulted in basically the whole world being exposed to them.

They're hormone disruptors that cause a lot of side effects like decrease of intelligence, weight gain, early/late puberty and it is impossible to escape them completely since even though they're no longer manufactured (at least not in the USA legally) they take a long time to break down in the environment.

https://www.clearwater.org/news/pcbhealth.html