I came up with another flaw in the theory for earthing. They claim: "that the Earth's surface contains free electrons that can be transferred to human bodies via direct contact, and that these electrons then act as antioxidants that help neutralize free radicals in our bodies".
No, that seems completely wrong. It took me a while to figure it out, since I'm brainfogged and it's been a long time since I studied chemistry, but the reactions in our bodies involve covalent bonds. These do not involve free electrons; they involve shared electrons. Two (or more) atoms get close enough to share electrons; it does not involve free electrons at all. Free radicals will be completely unaffected.
There are also ionic bonds in body chemistry, but those also don't involve free electrons. An acid solution has a net positive charge, but grounding that electrically doesn't 'draw free electrons from the earth to neutralize the charge' I can't think of any chemical reactions that change if they're connected to a negative or positive charged source. Batteries involve electron flow, but those chemical reactions also are unaffected by static charges.
I won't claim that people can not be affected in some way by earthing, but the claimed theories for how it works are badly flawed. At least two of their claims are completely wrong (static charges entering the body, and body chemistry being affected by static charges).
I assume the theory is based on the type of electron flow that is observed in metals, but I too find it very difficult to stomach.
@Iknovate , I had a look at that first paper you linked that
@Wishful was discussing. I agree with what Wishful said regarding the quality of the study and just wanted to add a few things.
The authors declare funding from "Earth FX Inc" at the end, a company that sells earthing products. While this is a declared conflict of interest, it is something to consider.
Re experimental design, they have one test group and are doing repeat measures on the same patients. While this is fine, the timing and the fact that it is a finger prick of blood makes it seem that the people conducting the experiment would have no way of clearly blinding the tests - ie they have to measure soon after the sample is taken as it will dry up and the cells will die. It would have been a superior design to at least split the subjects into an experimental and control group at random, and have the person measuring blinded to the group of the subject. It would furthermore have been better to include 10 in each group, but considering the extreme difference they measured, they would likely have achieved statistical significance with an n of 5.
It would also have been better if they had two (or three) assessors measuring each sample, and then they should take the average of the two measurements. These would swap orders with each subject to reduce effects of measuring order.
They used a set value for blood viscosity for their zeta potential calculation, based on a single citation. This is a little ridiculous, considering that the reason they are doing the test is largely to demonstrate a difference in viscosity.. It would have been far better to simply cannulate the subjects and draw a vial of blood at each time point. The viscosity of the blood could then be directly measured using a rheometer.. They could then not only provide a true viscosity measurement for each subject before and after, but they could calculate zeta potential based on the actual viscosity of each sample. This would have made their conclusions far more solid.
I, however, doubt that they would have found the same result doing this. I do wonder if they purposefully excluded such a measure because they suspected the effect would not be conserved between assays.
I did not look over the other studies that you linked. I think it's important to remember that sometimes reading the abstract is not enough, and you have to dig into the details.