�y��vlog

The absence of a specific polyphenol, syringic acid, served to identify the wine as white.

But before McGivern could look for evidence of polyphenol degradation in the core samples, she first had to create a database of gene sequences that corresponded to polyphenol metabolism.

Sure enough, she said, polyphenol metabolism was happening.

"What we found was that genes across 58 different polyphenol pathways were expressed," McGivern said.

But no studies, including decades of research on one polyphenol called resveratrol, have definitively linked the amounts that you get from red wine to good health, Cho said.