Laboratory of Histology and Cytology, Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Am J Clin Nutr. 2012 Apr;95(4):845-50. doi: 10.3945/ajcn.111.018606. Epub 2012 Feb 29.
Capsinoids-nonpungent capsaicin analogs-are known to activate brown adipose tissue (BAT) thermogenesis and whole-body energy expenditure (EE) in small rodents. BAT activity can be assessed by [¹⁸F]fluorodeoxyglucose-positron emission tomography (FDG-PET) in humans.
The aims of the current study were to examine the acute effects of capsinoid ingestion on EE and to analyze its relation to BAT activity in humans.
Eighteen healthy men aged 20-32 y underwent FDG-PET after 2 h of cold exposure (19°C) while wearing light clothing. Whole-body EE and skin temperature, after oral ingestion of capsinoids (9 mg), were measured for 2 h under warm conditions (27°C) in a single-blind, randomized, placebo-controlled, crossover design.
When exposed to cold, 10 subjects showed marked FDG uptake into adipose tissue of the supraclavicular and paraspinal regions (BAT-positive group), whereas the remaining 8 subjects (BAT-negative group) showed no detectable uptake. Under warm conditions (27°C), the mean (±SEM) resting EE was 6114 ± 226 kJ/d in the BAT-positive group and 6307 ± 156 kJ/d in the BAT-negative group (NS). EE increased by 15.2 ± 2.6 kJ/h in 1 h in the BAT-positive group and by 1.7 ± 3.8 kJ/h in the BAT-negative group after oral ingestion of capsinoids (P < 0.01). Placebo ingestion produced no significant change in either group. Neither capsinoids nor placebo changed the skin temperature in various regions, including regions close to BAT deposits.
Capsinoid ingestion increases EE through the activation of BAT in humans. This trial was registered at http://www.umin.ac.jp/ctr/ as UMIN 000006073.
辣椒素类似物——无辣味的辣椒素类似物，已知可激活棕色脂肪组织（BAT）产热和全身能量消耗（EE），在小型啮齿动物中。在人类中，BAT 活性可以通过 [¹⁸F]氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）来评估。
本研究的目的是检查辣椒素摄入对 EE 的急性影响，并分析其与人类 BAT 活性的关系。
18 名年龄在 20-32 岁的健康男性在穿着轻便衣物的情况下，在 19°C 的寒冷环境下暴露 2 小时后进行 FDG-PET。在单盲、随机、安慰剂对照、交叉设计下，在温暖条件（27°C）下口服辣椒素（9 毫克）后 2 小时内测量全身 EE 和皮肤温度。
在暴露于寒冷时，10 名受试者的锁骨上和脊柱旁区域的脂肪组织中出现明显的 FDG 摄取（BAT 阳性组），而其余 8 名受试者（BAT 阴性组）未检测到摄取。在温暖条件（27°C）下，BAT 阳性组的静息 EE 平均值（±SEM）为 6114 ± 226 kJ/d，BAT 阴性组为 6307 ± 156 kJ/d（无统计学意义）。在 BAT 阳性组中，口服辣椒素后 1 小时内 EE 增加了 15.2 ± 2.6 kJ/h，而在 BAT 阴性组中增加了 1.7 ± 3.8 kJ/h（P < 0.01）。安慰剂摄入在两组中均未引起显著变化。辣椒素和安慰剂都没有改变包括靠近 BAT 沉积区域在内的各个区域的皮肤温度。
辣椒素摄入通过激活人类的 BAT 来增加 EE。该试验在 http://www.umin.ac.jp/ctr/ 注册，注册号为 UMIN 000006073。
