Abstract：
Dietary countermeasures to mitigate detrimental spaceflight-induced effects on bone health would alleviate the requirements and the consequences imposed by other types of countermeasures for this risk. We hypothesised that antioxidant supplementation during 60 days of 6° head-down tilt bed rest (HDBR), an analogue of spaceflight, would have a protective effect on bone mineral density (BMD), content (BMC) and bone structure parameters. An exploratory, randomised, controlled, single-blind intervention trial was conducted in a parallel design with 20 healthy male volunteers (age 34 ± 8 y, weight 74 ± 6 kg). The study included 14 days of baseline data collection (BDC) before bed rest, followed by 60 days of HDBR and a 14-day recovery period. Ten subjects in the antioxidant group received a supplement (741 mg/d polyphenols, 2.1 g/d omega-3 fatty acids, 168 mg/d vitamin E and 80 μg/d selenium) daily. Ten subjects in the control group received no supplement. The diet was consistent with dietary reference intakes, individually tailored based on the subject\'s bodyweight and strictly controlled. We measured whole-body, lumbar spine and femur BMD and BMC, as well as BMD of the cortical and trabecular compartments of the distal radius and tibia, and cortical and trabecular thickness during BDC, HDBR and recovery. Data were analysed using linear mixed models. The supplementation of an antioxidant cocktail did not mitigate the deteriorating effects of HDBR on BMD, BMC and bone structure parameters. Our findings do not support a recommendation for antioxidant supplementation for astronauts.
摘要：
减轻航天飞行对骨骼健康的有害影响的饮食对策将减轻其他类型对策对这种风险的要求和后果。我们假设在60天的6°头朝下倾斜卧床休息（HDBR）期间补充抗氧化剂，太空飞行的模拟，对骨密度（BMD）有保护作用，含量(BMC)和骨结构参数。探索性的，随机化，控制,单盲干预试验采用平行设计，对20名健康男性志愿者(年龄34±8岁，重量74±6公斤)。该研究包括卧床休息前14天的基线数据收集（BDC），接下来是60天的HDBR和14天的恢复期。抗氧化剂组中的10名受试者接受了补充剂(741毫克/天的多酚，2.1g/domega-3脂肪酸，168mg/d维生素E和80μg/d硒)每日。对照组中的10名受试者未接受补充剂。饮食与饮食参考摄入量一致，根据受试者的体重单独定制并严格控制。我们测量了全身，腰椎和股骨BMD和BMC，以及桡骨远端和胫骨的皮质和小梁隔室的BMD，BDC期间皮质和小梁厚度，HDBR和恢复。使用线性混合模型分析数据。补充抗氧化剂鸡尾酒并不能减轻HDBR对BMD的恶化影响，BMC和骨结构参数。我们的发现不支持宇航员补充抗氧化剂的建议。
