A recent study from the University of California, Davis reveals that red wine headaches may be triggered by quercetin, a flavanol naturally found in red wines and other fruits. Quercetin inhibits alcohol metabolism, leading to the accumulation of the toxin acetaldehyde, which causes headaches, facial flushing, and nausea. The research aims to compare quercetin levels in different red wines to understand and address the factors contributing to red wine headaches.