Multiple studies demonstrate that specific dietary factors (such as ingesting high levels of histidine or histamine) and physiological mechanisms (including stress, circadian rhythms, and oxidative imbalances) elevate histamine levels in the body.
The claim is specific, empirical, and testable. Several retrieved papers directly examine how dietary intake (histidine/histamine) and physiological factors (stress, hemolysis/heme, circadian clocks) impact histamine levels, providing consistent supporting evidence without refutations.