The influence of chronic yogurt consumption on immunity

There has been increased interest in the study of nutrition and immunity. This is especially true with respect to the hypothesis that consumption of specific foods may reduce an individual's susceptibility to the establishment and/or progression of immunologic disease. Although an increased intake of a specific food may improve health status in select cases, chronic consumption of large amounts of one specific food may in fact be detrimental. The studies described here examined the long-term effect of yogurt consumption on two different age populations, young adults (20-40 y) and senior adults (55-70 y). There were three study groups per age group, live-culture yogurt, pasteurized yogurt and control (no yogurt), given 200 g/d of yogurt for 1 y. The subjects completed a questionnaire detailing health parameters on a weekly basis and a 4-d food record was taken monthly. Blood was taken every 3 mo and complete blood chemistry, blood count, total and specific immunoglobulin (Ig)E, and interferon-gamma (IFN-gamma) production measured. Yogurt consumption, especially for the live-culture groups, was associated with a decrease in allergic symptoms in both age groups. Seniors in the control group experienced an increase in both total and LDL cholesterol, whereas those in the yogurt groups remained stable during the course of the study. There was little effect on IFN-gamma and IgE production, although seniors in the yogurt group had lower levels of total IgE throughout the year.