High-pressure treatment, e.g. used as an alternative method for food preservation, affects protein cross-linking and glycation reactions. These reactions were monitored by using mainly milk proteins in the absence and presence of different saccharides or dicarbonyl compounds. Without carbohydrates, protein cross-linking of casein is enhanced by pressure through the formation of dehydroalanine-derived lysinoalanine. A similar effect can be observed in wool, where pressure accelerates the formation of lanthionine. In contrast, saccharide or dicarbonyl compound-induced cross-linking is constrained by high pressures. Despite this, pressure is able to accelerate the degradation of sugar or carbonyl compounds, as could be seen by the measurement of their residual contents in the examined test preparations.