Yogurt consumption does not enhance immune function in healthy premenopausal women

Fermented milk products may protect against breast cancer by stimulating im munologic activity. Twenty-five women [24.0 +/- 0.7 (SE) yr] were assigned randomly to two groups. control (n = 12) and yogurt treatment (n = 13). Con trols refrained from yogurt products for three months, whereas the yogurt t reatment group consumed two cups (454 g/day) of commercially produced yogur t for three consecutive months. Prior yogurt consumption did not exceed 4-6 cups/mo, and subjects consumed their usual diet during the study. Three-da y diet records and fasting midluteal blood samples were obtained during sub jects' first, second, and fourth menstrual cycles (baseline, Month I, and M onth 3, respectively). Macronutrient intakes differed between groups only f or carbohydrate. Calcium intake increased for yogurt consumers during inter vention. Lymphocyte proliferation induced by concanavalin A, phytohemagglut inin, and pokeweed mitogen, interleukin 2 production, and cytotoxic T lymph ocyte-mediated cytotoxicity was assessed after baseline and Months I and 3 for both groups. No significant immune differences between the control and yoghurt treatment group were observed for concanavalin A, phytohemagglutini n, pokeweed mitogen, interleukin-a, or cytotoxicity. In conclusion, three m onths of yogurt consumption did not enhance ex vivo cell-mediated immune fu nction in young women.