The toxin that is destroying their fingers is called oxalate. It’s also connected to cancers, nephropathy, autoimmune conditions, damaged eye sight, and numerous other ailments.
Human beings are not supposed to eat improperly prepared nuts. Every culture in antiquity that did eat nuts sparingly for additional calories when meat/fat/fruit were sparse, had VERY specific preparation practices to ensure the toxins were reduced. These practices were generally soaking and fermentation, sun drying/curing, or using salts/vinegars to extract toxins.
Most people have no idea that the spinach, rhubarb, kale, cashews, or almonds they are eating could be causing a litany of symptoms that a doctor diagnosed as something else. There are even papers connecting breast cancer to oxalate crystals, as well as neurological conditions getting exacerbated, like autism. Oxalate is a toxin plants use to defend themselves from overconsumption. It’s goal is to kill whatever animal eats to much of it. Go eat 2lb of rhubarb and you’ll literally die of kidney failure. It can be that toxic.
Oxalates Induce Breast Cancer
https://bmccancer.biomedcentral.com/articles/10.1186/s12885-015-1747-2
To view the video of the cashew processing that damages the hands: https://twitter.com/Inversionism/status/1686804569513226255