With the ever increasing amount and new types of pollutants, I wonder if one day blood letting for health purposes will make a comeback. Our kidneys can't filter everything, some stuff just very slowly, so it accumulates in the blood or somewhere else. Heavy metals, PCBs, micro plastics. When we reach old age our bodies are basically toxic chemical waste.

Removing it with the blood is easy and very effective. It even removes all the weird molecules we haven't discovered yet.