Abstract
BACKGROUND/OBJECTIVES: This 8-week randomized pilot intervention trial examined the effects of Greek yogurt (GY) supplementation on markers of bone turnover and inflammation in older adult exercisers. METHODS: A total of 48 participants aged 55+ completed this 8-week intervention: 33 exercisers randomized to exercisers receiving GY (GYEX, n = 18, 12 females) and exercisers without GY (NYEX, n = 15, 12 females), and a group of 15 age-matched, community-dwelling, non-exercisers also receiving GY (GYNE, n = 15, 10 females). Exercisers were enrolled in a moderate-intensity community-based exercise program. GYEX and GYNE supplemented their diet with two daily servings of 175 g of GY (17 g protein, 225 mg calcium per serving). Assessments at baseline and week 8 included dietary intake, body composition, and fasting blood samples for bone markers and pro-inflammatory cytokines. RESULTS: Body mass increased modestly across groups (time effect, p = 0.033), with no changes in body fat. C-terminal telopeptide of type I collagen (bone resorption marker) increased 14% in GYEX (time × group interaction, p = 0.022). Osteoprotegerin (bone formation regulator) decreased overall by 4% (time effect, p = 0.002). Dickkopf-1 (bone formation inhibitor) increased by 13% (p = 0.008) in GYNE but not in exercisers (time × group interaction, p = 0.018). Interleukin 1β and interleukin 6 showed significant interactions (p = 0.043 and p = 0.023), where interleukin 1β increased by 80% (p = 0.007) and interleukin 6 decreased by 89% (p < 0.001) in GYNE, but remained stable in exercisers. Tumor necrosis factor alpha remained unchanged. CONCLUSIONS: Although the observed effects of GY on the assessed biomarkers were limited and should be interpreted cautiously due to pilot design and statistical constraints, they highlight the need for longer interventions to determine whether whole-food dairy proteins can meaningfully support skeletal and immune health in older adults.