Dietary olive oil enhances murine lymphocyte calcium uptake

Background: Dietary lipids enhance immune function and improve outcome from injury or infection in animal models. We tested the hypothesis that amount, type, or both, of dietary lipid increases intracellular calcium concentration, a surrogate for lymphocyte activation. Methods: Mice were fed 2 weeks on semipurified diets with 5% (by weight [w/w]), 10% (w/w), or 20% (w/w) dietary fat consisting of coconut, olive, safflower, or linseed oil. Changes in intracellular calcium concentration after mitogen stimulation of splenic lymphocytes was estimated by using flow cytometry. Results: Olive oil diets increase intracellular calcium concentration after concanavalin A, lipopolysaccharide, and CD3 stimulation. On the other hand, linseed oil (which is high in omega-3 fatty acids, which have been shown in other studies to enhance immune function) depresses intracellular calcium levels. The amount of dietary fat had no effect on intracellular calcium. Conclusion: Olive oil merits further study in the application of nutritional pharmacology to immunomodulation of the critically injured, because it may enhance lymphocyte function.