Gastroprotection by dairy foods against stress-induced ulcerogenesis in rats

We investigated the ability of three dairy foods to prevent stress-induced gastric lesions and bleeding in rats. Skim milk, whole milk, and cream were all significantly gastroprotective with the greatest protection seen with the highest fat dairy food. Pretreatment of rats with cream for up to 2 hr prior to stress maintained a portion of the protective effect. Lipid extracts of cream, but not skim milk or whole milk, were gastroprotective. Surface hydrophobicity of the gastric mucosa was reduced by stress, but was maintained at prestress levels by treatment with milk, cream, or their lipid extracts, although this effect was not sufficient for protection in stressed rats. Alterations in gastric pH or titratable acid could not explain the protective effects of dairy foods or their lipid extracts. Milk was more gastroprotective in stressed rats than another food of equal caloric value. We conclude that both the lipid and nonlipid fractions of dairy foods possess gastroprotective activity against stress-induced ulcerogenesis in rats, a property that may be of therapeutic value for man.