Capsinoids activate brown adipose tissue (BAT) with increased energy expenditure associated with subthreshold 18-fluorine fluorodeoxyglucose uptake in BAT-positive humans confirmed by positron emission tomography scan

Am J Clin Nutr. 2018 Jan 1;107(1):62-70. doi: 10.1093/ajcn/nqx025.


Background: Capsinoids are reported to increase energy expenditure (EE) via brown adipose tissue (BAT) stimulation. However, imaging of BAT activation by capsinoids remains limited. Because BAT activation is a potential therapeutic strategy for obesity and related metabolic disorders, we sought to prove that capsinoid-induced BAT activation can be visualized by 18-fluorine fluorodeoxyglucose (18F-FDG) positron emission tomography (PET).

Objective: We compared capsinoids and cold exposure on BAT activation and whole-body EE.

Design: Twenty healthy participants (8 men, 12 women) with a mean age of 26 y (range: 21-35 y) and a body mass index (kg/m2) of 21.7 (range: 18.5-26.0) underwent 18F-FDG PET and whole-body calorimetry after ingestion of 12 mg capsinoids or ≤2 h of cold exposure (∼14.5°C) in a crossover design. Mean standardized uptake values (SUVs) of the region of interest and BAT volumes were calculated. Blood metabolites were measured before and 2 h after each treatment.

Results: All of the participants showed negligible 18F-FDG uptake post-capsinoid ingestion. Upon cold exposure, 12 participants showed avid 18F-FDG uptake into supraclavicular and lateral neck adipose tissues (BAT-positive group), whereas the remaining 8 participants (BAT-negative group) showed undetectable uptake. Capsinoids and cold exposure increased EE, although cold induced a 2-fold increase in whole-body EE and higher fat oxidation, insulin sensitivity, and HDL cholesterol compared with capsinoids.

Conclusions: Capsinoids only increased EE in BAT-positive participants, which suggests that BAT mediates EE evoked by capsinoids. This implies that capsinoids stimulate BAT to a lesser degree than cold exposure as evidenced by 18F-FDG uptake below the presently accepted SUV thresholds defining BAT activation. This trial was registered at as NCT02964442.

Keywords: blood metabolites; brown adipose tissue; capsinoids; cold; energy expenditure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue, Brown / drug effects*
  • Adipose Tissue, Brown / metabolism
  • Adiposity*
  • Adult
  • Body Mass Index
  • Calorimetry, Indirect
  • Capsicum / chemistry*
  • Cold Temperature
  • Cross-Over Studies
  • Energy Metabolism*
  • Female
  • Fluorodeoxyglucose F18 / administration & dosage
  • Fluorodeoxyglucose F18 / pharmacokinetics*
  • Humans
  • Male
  • Non-Randomized Controlled Trials as Topic
  • Plant Extracts / administration & dosage
  • Positron-Emission Tomography*
  • Young Adult


  • Plant Extracts
  • Fluorodeoxyglucose F18

Associated data