It would probably be more interesting to study people who have high-copper diets or who handle pennies frequently. The amount of systemic copper from a bracelet

It would probably be more interesting to study people who have high-copper diets or who handle pennies frequently. The amount of systemic copper from a bracelet would likely be a small factor compared to copper ingestion. There are also people who have various illnesses that lead them to strictly avoid foods with a lot of copper, and we might want to see how those people fare later in life.