Effects of Greek Yogurt Supplementation and Exercise on Markers of Bone Turnover and Inflammation in Older Adult Exercisers: An 8-Week Pilot Intervention Trial.
Although the observed effects of Greek yogurt on 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.
Key Findings
Results
C-terminal telopeptide of type I collagen (CTX), a marker of bone resorption, increased by 14% in exercisers receiving Greek yogurt (GYEX) over 8 weeks.
The increase was significant as a time × group interaction (p = 0.022).
This change was observed in GYEX (n = 18, 12 females) but not in exercisers without Greek yogurt (NYEX, n = 15) or non-exercisers receiving Greek yogurt (GYNE, n = 15).
CTX is a marker of bone resorption, and its increase in the exercising yogurt group was an unexpected finding.
Participants were enrolled in a moderate-intensity community-based exercise program and consumed two daily servings of 175 g Greek yogurt (17 g protein, 225 mg calcium per serving).
Results
Osteoprotegerin, a bone formation regulator, decreased overall by 4% across all groups over the 8-week intervention.
The decrease was a significant main effect of time (p = 0.002).
This was a general time effect with no significant group interaction, meaning the decrease occurred regardless of exercise or Greek yogurt supplementation.
Total sample included 48 participants aged 55+ across three groups: GYEX (n = 18), NYEX (n = 15), and GYNE (n = 15).
Results
Dickkopf-1 (DKK-1), a bone formation inhibitor, increased by 13% in non-exercising Greek yogurt consumers (GYNE) but not in exercisers.
The time × group interaction was significant (p = 0.018).
The increase of 13% was specific to GYNE (n = 15, 10 females).
Exercisers receiving Greek yogurt (GYEX) and exercisers not receiving Greek yogurt (NYEX) did not show significant changes in DKK-1.
This suggests that exercise may have attenuated the rise in this bone formation inhibitor associated with Greek yogurt supplementation in non-exercisers.
Results
Interleukin-1β (IL-1β) increased by 80% in non-exercising Greek yogurt consumers (GYNE) but remained stable in exercising groups.
The time × group interaction for IL-1β was significant (p = 0.043).
Within GYNE, the 80% increase in IL-1β was significant (p = 0.007).
IL-1β remained stable in both GYEX and NYEX over the 8-week period.
IL-1β is a pro-inflammatory cytokine, and its increase was observed only in the non-exercising supplemented group.
Results
Interleukin-6 (IL-6) decreased by 89% in non-exercising Greek yogurt consumers (GYNE) but remained stable in exercising groups.
The time × group interaction for IL-6 was significant (p = 0.023).
Within GYNE, the 89% decrease in IL-6 was significant (p < 0.001).
IL-6 remained stable in both GYEX and NYEX over the 8-week period.
The simultaneous increase in IL-1β and decrease in IL-6 in GYNE represents divergent inflammatory marker responses to Greek yogurt supplementation in non-exercisers.
Results
Tumor necrosis factor alpha (TNF-α) remained unchanged across all groups and time points.
No significant main effects of time or time × group interactions were found for TNF-α.
This null finding applied to all three groups: GYEX, NYEX, and GYNE.
TNF-α is a pro-inflammatory cytokine assessed via fasting blood samples at baseline and week 8.
Results
Body mass increased modestly across all groups over the 8-week intervention, with no changes in body fat.
The increase in body mass was a significant main effect of time (p = 0.033).
No significant changes in body fat percentage were observed across any group.
Body composition was assessed at baseline and week 8 as part of the study protocol.
The modest body mass increase occurred regardless of group assignment (GYEX, NYEX, or GYNE).
Methods
The study was designed as a randomized pilot intervention trial with 48 participants aged 55 or older across three groups over 8 weeks.
Groups included exercisers receiving Greek yogurt (GYEX, n = 18, 12 females), exercisers without Greek yogurt (NYEX, n = 15, 12 females), and non-exercising Greek yogurt consumers (GYNE, n = 15, 10 females).
Greek yogurt supplementation consisted of two daily servings of 175 g providing 17 g protein and 225 mg calcium per serving.
Exercisers participated in a moderate-intensity community-based exercise program.
Assessments included dietary intake, body composition, and fasting blood samples for bone markers and pro-inflammatory cytokines at baseline and week 8.
The authors note that findings should be interpreted cautiously due to pilot design and statistical constraints.
Bell M, Narciso P, Baker E, Falk B, Roy B, Josse A, et al.. (2025). Effects of Greek Yogurt Supplementation and Exercise on Markers of Bone Turnover and Inflammation in Older Adult Exercisers: An 8-Week Pilot Intervention Trial.. Nutrients. https://doi.org/10.3390/nu17243902