Rationale and study design of Randomized Controlled Trial of Dietary Supplementation with prune (dried plums) on bone density, geometry, and estimated bone strength in postmenopausal women: The Prune study

Prune supplementation for 12 months alters the gut microbiome in postmenopausal women

“…Exclusion criteria included consumption of any natural dietary supplement containing phenolics, consumption of >1 cup per day of blueberries or apples for at least 2 months prior to study entry, a history of bone fractures after age 50, significant chronic disease, and consumption of certain medicines affecting bone metabolism, as described previously. 22 2.2.3. Prune intervention.…”

“…Prune groups underwent a “run-in” period to slowly increase prune consumption in their diet, as previously described. 22 All participants were supplemented as necessary to meet the required intake of 1200 mg calcium and 800 IU vitamin D 3 daily (Nature Made Pharmavite LLC, West Hills, CA). This supplementation was related to the primary outcome of the trial, bone health.…”

“…Urinary samples were analyzed to determine total phenolics and targeted phenolic metabolites as previously described in detail. 22 Briefly, total urinary phenolics were determined from a 48-hour pooled urine sample after solid phase extraction (SPE) extraction by the Folin–Ciocalteu microplate method 24 and corrected for creatinine content (colorimetric assay kit 500701, Cayman chemical, Ann Arbor, MI). 25 A targeted set of 21 prune-derived phenolic metabolites were measured by ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) using a Waters UPLC Acquity H Class system equipped with a Xevo TQD Mass Spectrometric detector as described previously.…”

“…22 C-reactive protein (CRP) in serum was quantified in duplicate using an Immulite (Siemens Healthcare, Munich, Germany) high-sensitivity CRP kit as per manufacturer's instructions. Peripheral blood mononuclear cells (PBMCs) were isolated as previously described 22 and counted for use in functional and phenotypic analyses as previously described. 26 2.6.1.…”

“…A detailed description of the design of this study has been published. 22 Briefly, postmenopausal women aged 55-75 years were enrolled at Pennsylvania State University (PSU) and randomized into one of three treatments: 50 g prunes (i.e., 4-6 prunes), 100 g prunes (10-12 prunes), or a no prune control group. Prunes were consumed daily for 12 months in the two treatment groups.…”