Prunes may blunt adverse effects of oral contraceptives on bone health in young adult women: a randomized clinical trial
Background: Oral contraceptives (OCs) may promote bone loss, thereby leading to suboptimal bone health later in life. Research is needed to determine whether dietary interventions can blunt OC-related bone loss; prune consumption, shown to be effective in improving bone density in previous studies, could provide a safe and inexpensive solution. Objectives: The purpose of this study was to determine whether 12 mo of consuming 50 g of prunes daily would prevent bone loss or increase bone accrual in young (18–25 y) OC users. Methods: Ninety women were randomly assigned to a control group not using OCs (non-OC), an OC group not consuming prunes (OC), and an OC group consuming 50 g prunes daily (OC+P) for 12 mo. Bone mineral density (BMD) was measured at baseline and after 12 mo via dual-energy X-ray absorptiometry (at all sites) and peripheral quantitative computed tomography (at tibia). Blood samples were collected at baseline and after 6 and 12 mo to assess biomarkers. Results: There were no significant differences between groups for dietary intake, physical activity, serum tartrate-resistant acid phosphatase-5b, or bone alkaline phosphatase concentrations. Baseline serum C-reactive protein and vitamin D concentrations were higher (P < 0.001) for OC and OC+P groups than those in the non-OC group. Serum parathyroid hormone was higher for non-OC group than OC group at both baseline (P = 0.049) and final (P = 0.032). BMD measured by dual-energy X-ray absorptiometry at all sites did not change among groups. Ultradistal radius BMD increased over time (P < 0.05) within non-OC and OC+P groups. Trabecular density of the distal tibia as measured by peripheral quantitative computed tomography decreased from baseline to 12 mo within the OC group only (P = 0.016). Conclusions: OC use tended to promote minor negative effects on bone and consuming prunes tended to provide a potential protective effect on trabecular density of the distal tibia and ultradistal radius. https://doi.org/10.1016/j.cdnut.2024.104417
Prune Consumption Attenuates Proinflammatory Cytokine Secretion and Alters Monocyte Activation in Postmenopausal Women: Secondary Outcome Analysis of a 12-Mo Randomized Controlled Trial: The Prune Study
Background: Proinflammatory cytokines are implicated in the pathophysiology of postmenopausal bone loss. Clinical studies demonstrate that prunes prevent bone mineral density loss; however, the mechanism underlying this effect is unknown. Objective: We investigated the effect of prune supplementation on immune, inflammatory, and oxidative stress markers. Methods: A secondary analysis was conducted in the Prune Study, a single-center, parallel-arm, 12-mo randomized controlled trial of postmenopausal women (55-75 y old; n = 235 recruited; n = 183 completed) who were assigned to 1 of 3 groups: "no-prune" control, 50 g prune/d and 100 g prune/d groups. At baseline and after 12 mo of intervention, blood samples were collected to measure serum high-sensitivity C-reactive protein (hs-CRP), serum total antioxidant capacity (TAC), plasma 8-isoprostane, proinflammatory cytokines [interleukin (IL)-1β, IL-6, IL-8, monocyte chemoattractant protein-1, and tumor necrosis factor (TNF)-α] concentrations in plasma and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) culture supernatants, and the percentage and activation of circulating monocytes, as secondary outcomes. Results: Prune supplementation did not alter hs-CRP, TAC, 8-isoprostane, and plasma cytokine concentrations. However, percent change from baseline in circulating activated monocytes was lower in the 100 g prune/d group compared with the control group (mean ± SD, -1.8% ± 4.0% in 100 g prune/d compared with 0.1% ± 2.9% in control; P < 0.01). Furthermore, in LPS-stimulated PBMC supernatants, the percent change from baseline in TNF-α secretion was lower in the 50 g prune/d group compared with the control group (-4.4% ± 43.0% in 50 g prune/d compared with 24.3% ± 70.7% in control; P < 0.01), and the percent change from baseline in IL-1β, IL-6, and IL-8 secretion was lower in the 100 g prune/d group compared with the control group (-8.9% ± 61.6%, -4.3% ± 75.3%, -14.3% ± 60.8% in 100 g prune/d compared with 46.9% ± 107.4%, 16.9% ± 70.6%, 39.8% ± 90.8% in control for IL-1β, IL-6, and IL-8, respectively; all P < 0.05). Conclusions: Dietary supplementation with 50-100 g prunes for 12 mo reduced proinflammatory cytokine secretion from PBMCs and suppressed the circulating levels of activated monocytes in postmenopausal women. This trial was registered at clinicaltrials.gov as NCT02822378. https://doi.org/10.1016/j.tjnut.2023.11.014
Gut microbes differ in postmenopausal women responding to prunes to maintain hip bone mineral density
Foods high in phenolics such as prunes have been shown to exert protective effects on bone mineral density (BMD), but only certain individuals experience these benefits. This post-hoc analysis of a 12-month randomized controlled trial aimed to identify the relationship among the gut microbiome, immune responses, and bone protective effects of prunes on postmenopausal women. Subjects who consumed 50-100 g prunes daily were divided into responders (n = 20) and non-responders (n = 32) based on percent change in total hip bone mineral density (BMD, ≥1% or ≤-1% change, respectively). DXA scans were used to determine body composition and BMD. Immune markers were measured using immunoassays and flow cytometry. Targeted phenolic metabolites were analyzed using ultra performance liquid chromatography-tandem mass spectrometry. The fecal microbiota was characterized through 16S rRNA gene PCR amplicon sequencing. After 12 months of prune consumption, anti-inflammatory markers showed responders had significantly lower levels of IL-1β and TNF-α. QIIME2 sequence analysis showed that microbiomes of responders and non-responders differed in alpha (Shannon and Faith PD, Kruskal-Wallis p < 0.05) and beta diversity (unweighted Unifrac, PERMANOVA p < 0.04) metrics both before and after prune treatment. Furthermore, responders had a higher abundance of bacterial families Oscillospiraceae and Lachnospiraceae (ANCOM-BC p < 0.05). These findings provide evidence that postmenopausal women with initial low BMD can benefit from prunes if they host certain gut microbes. These insights can guide precision nutrition strategies to improve BMD tailored to diet and microbiome composition.
https://doi.org/10.3389/fnut.2024.1389638
Prunes preserve cortical density and estimated strength of the tibia in a 12-month randomized controlled trial in postmenopausal women: The Prune Study
Summary: Non-pharmacological therapies, such as whole-food interventions, are gaining interest as potential approaches to prevent and/or treat low bone mineral density (BMD) in postmenopausal women. Previously, prune consumption preserved two-dimensional BMD at the total hip. Here we demonstrate that prune consumption preserved three-dimensional BMD and estimated strength at the tibia. Purpose: Dietary consumption of prunes has favorable impacts on areal bone mineral density (aBMD); however, more research is necessary to understand the influence on volumetric BMD (vBMD), bone geometry, and estimated bone strength. Methods: This investigation was a single center, parallel arm 12-month randomized controlled trial (RCT; NCT02822378) to evaluate the effects of 50 g and 100 g of prunes vs. a Control group on vBMD, bone geometry, and estimated strength of the radius and tibia via peripheral quantitative computed tomography (pQCT) in postmenopausal women. Women (age 62.1 ± 5.0yrs) were randomized into Control (n = 78), 50 g Prune (n = 79), or 100 g Prune (n = 78) groups. General linear mixed effects (LME) modeling was used to assess changes over time and percent change from baseline was compared between groups. Results:_ The most notable effects were observed at the 14% diaphyseal tibia in the Pooled (50 g + 100 g) Prune group, in which group × time interactions were observed for cortical vBMD (p = 0.012) and estimated bone strength (SSI; p = 0.024); all of which decreased in the Control vs. no change in the Pooled Prune group from baseline to 12 months/post. Conclusion: Prune consumption for 12 months preserved cortical bone structure and estimated bone strength at the weight-bearing tibia in postmenopausal women.
https://doi.org/10.1007/s00198-024-07031-6