Foods Potential Immune Modulators in Dairy

Components in dairy foods that may modulate immune response, either through specific or non-specific means, include:

v Whole casein, alpha s, beta and kappa casein

v Casein glycomacropeptide

v Whole whey protein

v Lactoferrin

v Lactoperoxidase

v Immunoglobulin G

v Peptides

v Conjugated linoleic acid (CLA)

v Probiotic products ( i.e. Yogurt, acidophilus milk and related fermented dairy foods

Effects on the immune system include:

v Lymphocyte suppression and or proliferation depending on product and method of testing

v Enhanced secretory IgA

v Increased cytokine production

v Antibody production

v Hypersensitivity

v Macrophage function

v Granulocyte function

Most of the evidence gathered in the past 5-10 years has been either in vitro or in vivo, with very little direct human clinical trials. Both methods have their advantages and disadvantages. Positive in vitro tests only provides evidence that the material being tested may have the potential to modify immune function when included in the diet. A dualistic approach is being used to a greater extent in recent work Whereas in vitro studies show mostly suppression of lymphocyte proliferation, in most vivo studies show a degree of immuno enhancement of lymphocyte function.

There is increasing suggestion that the Immunoregulatory action of the primary milk proteins is well balanced and that some components may serve to regulate the function of others (Wong, et al. 1997). Also, the Immunoregulatory effect of individual milk proteins becomes more clearly defined as the protein becomes more purified.

The variable results of studies relating to hypersensitivity, antibody production, macrophage and granulocyte function require more investigation to clearly differentiate the different responses to milk proteins.

Cross and Gill (2000) have emphasized that the” subtle interactions of milk derived proteins should be considered where interpreting results from controlled laboratory based stidues.”

Reviews:

Cross ML & Gill HS (2000)

Immunomodulatory properties of milk. British Journal of Nutrition 84 (Supplement 1):81-89.

Gill HS, Doull F, Rutherford KJ & Cross M L (2000)

Immunoregulatory peptides in bovine milk. British Journal of Nutrition 84 (Supplement 1): 111-117.