High Phenolic Beer Inhibits Protein Glycation In Vitro

​Protein glycation is a nonenzymatic process in which amino residues of proteins react with sugar groups, causing protein cross-linking. This contributes to many complications associated with diabetes. Phenolic compounds from fruits and vegetables have been found to inhibit protein glycation. Because of the high volume in which beer is consumed, it has the potential to be an excellent phenolic delivery system. We studied five beer styles (American pale ale, porter, stout, India pale ale, and Imperial India pale ale) for their phenolic and antioxidant contents and their effects on protein glycation. All beers were subjected to the Folin–Ciocalteu and ferric-reducing antioxidant power assays to assess the phenolic and antioxidant contents, respectively. All styles significantly inhibited protein glycation on a volumetric (4 µL/mL) basis, and all but one inhibited glycation based on phenolics (4 µg of phenols/mL). All beers significantly inhibited protein glycation based on antioxidant content (60 nmol of FeSO4 equivalents/mL), showing significant inhibition compared with both a control and a noncraft (i.e., mass production) beer. This demonstrates that certain beers can inhibit protein glycation at low concentrations and may, in certain individuals, significantly contribute to daily consumption of phenolic compounds.