https://www.naturalnews.com/2025-12-08-science-validates-coffees-emotional-power-with-one-caveat.html
"While the mood-lifting effect was widespread, the research also clarified a long-standing coffee paradox: why it is a panacea for some and poison for others. The determining factor is genetics, specifically variations in a gene called CYP1A2, which governs the liver enzyme responsible for metabolizing caffeine...'