McAlpine Michael D, Yumol Jenalyn L, Ward Wendy E
Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada.
Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada.
Front Nutr. 2021 Dec 7;8:798936. doi: 10.3389/fnut.2021.798936. eCollection 2021.
During pregnancy and lactation, maternal bone mineral density (BMD) is reduced as calcium is mobilized to support offspring bone development. In humans, BMD returns to pre-pregnancy levels shortly after delivery, shifting from a high rate of bone resorption during pregnancy and lactation, into a rapid phase of bone formation post-lactation. This rapid change in bone turnover may provide an opportunity to stimulate a greater gain in BMD and stronger trabecular and cortical structure than present pre-pregnancy. Providing polyphenols present in red rooibos herbal tea may promote such an effect. , red rooibos polyphenols stimulate osteoblast activity, reduce osteoclastic resorption, and increase mineral production. The study objective was to determine if consuming red rooibos from pre-pregnancy through to 4 months post-lactation resulted in a higher BMD and improved trabecular and cortical bone structure in a commonly used rat model. Female Sprague-Dawley rats ( = 42) were randomized to one of the following groups: PREG TEA (pregnant, received supplemental level of red rooibos in water: ~2.6 g /kg body weight/day in water), PREG WATER (pregnant, received water), or NONPREG CON (age-matched, non-pregnant control, received water) from 2 weeks pre-pregnancy (age 8 weeks) through to 4 months post-lactation. Rats were fed AIN-93G (pre-pregnancy through to the end of lactation) and AIN-93M (post-lactation onwards). BMD and trabecular structure (bone volume fraction, trabecular number, trabecular separation) were improved ( < 0.05) by 1- or 2-months post-lactation when comparing PREG TEA to PREG CON, though neither group recovered to the level of NONPREG CON. Cortical outcomes (cortical area fraction, cortical thickness, tissue mineral density) for PREG TEA and PREG CON were reduced ( < 0.05) following lactation but returned to the level of NONPREG CON by 2-months post-lactation, with the exception of cortical thickness. The lack of recovery of BMD and key outcomes of trabecular bone structure was unexpected. While consumption of red rooibos did not result in stronger bone post-lactation, red rooibos did support the partial recovery of trabecular BMD and bone structure following pregnancy and lactation. The findings also provide insight into the timing and dose of polyphenols to study in future interventions.
在怀孕和哺乳期间，母体骨矿物质密度（BMD）会降低，因为钙被动员起来以支持后代骨骼发育。在人类中，产后不久BMD会恢复到怀孕前水平，从怀孕和哺乳期间的高骨吸收速率，转变为哺乳后的快速骨形成阶段。骨转换的这种快速变化可能提供一个机会，以刺激BMD获得更大增加，并形成比怀孕前更强的小梁和皮质结构。提供红灌木茶中存在的多酚可能会促进这种效果。红灌木多酚可刺激成骨细胞活性，减少破骨细胞吸收，并增加矿物质生成。本研究的目的是确定从怀孕前到哺乳后4个月饮用红灌木茶，是否会在常用的大鼠模型中导致更高的BMD，并改善小梁和皮质骨结构。将42只雌性Sprague-Dawley大鼠随机分为以下组之一：孕期茶组（怀孕，饮用含补充水平红灌木的水：约2.6克/千克体重/天）、孕期水组（怀孕，饮用清水）或非孕期对照组（年龄匹配的非怀孕对照，饮用清水），从怀孕前2周（8周龄）到哺乳后4个月。大鼠在怀孕前至哺乳结束期间喂食AIN-93G饲料，哺乳后喂食AIN-93M饲料。与孕期对照组相比，孕期茶组在哺乳后1或2个月时，BMD和小梁结构（骨体积分数、小梁数量、小梁间距）得到改善（P<0.05），尽管两组均未恢复到非孕期对照组的水平。孕期茶组和孕期对照组的皮质指标（皮质面积分数、皮质厚度、组织矿物质密度）在哺乳后降低（P<0.05），但除皮质厚度外，在哺乳后2个月时恢复到非孕期对照组的水平。BMD和小梁骨结构关键指标未能恢复在意料之外。虽然饮用红灌木茶在哺乳后并未使骨骼更强壮，但红灌木茶确实支持怀孕和哺乳后小梁BMD和骨结构的部分恢复。这些发现还为未来干预研究中多酚的研究时机和剂量提供了见解。
