Nonpungent capsaicin analogs (capsinoids) increase energy expenditure through the activation of brown adipose tissue in humans

Am J Clin Nutr. 2012 Apr;95(4):845-50. doi: 10.3945/ajcn.111.018606. Epub 2012 Feb 29.


Background: 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.

Objectives: 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.

Design: 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.

Results: 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.

Conclusion: Capsinoid ingestion increases EE through the activation of BAT in humans. This trial was registered at as UMIN 000006073.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue, Brown / metabolism*
  • Adult
  • Anti-Obesity Agents / administration & dosage*
  • Basal Metabolism
  • Capsaicin / administration & dosage
  • Capsaicin / analogs & derivatives*
  • Cold Temperature
  • Contrast Media / pharmacokinetics
  • Cross-Over Studies
  • Dietary Supplements*
  • Energy Metabolism*
  • Fluorodeoxyglucose F18 / pharmacokinetics
  • Humans
  • Kinetics
  • Male
  • Membrane Transport Modulators / administration & dosage
  • Multimodal Imaging
  • Positron-Emission Tomography
  • Single-Blind Method
  • Skin Temperature
  • TRPV Cation Channels / agonists
  • Thermogenesis*
  • Tissue Distribution
  • Tomography, X-Ray Computed
  • Young Adult


  • Anti-Obesity Agents
  • Contrast Media
  • Membrane Transport Modulators
  • TRPV Cation Channels
  • TRPV1 protein, human
  • Fluorodeoxyglucose F18
  • Capsaicin