[Background] Brown adipose tissue (BAT) is a type of fat that serves as a site of non-shivering thermogenesis during cold exposure. It has been reported that higher BAT activity is related to lower whole body adiposity and accelerated glucose metabolism. Thus, BAT attracts much attention as a countermeasure to obesity and obesity-induced metabolic diseases. Muscle contractions modulates muscular environment and increases circulating myokines such as irisin and meteorin-like substance, resulting in the increase in BAT activity or browning of white adipose tissue. It is also reported that some kinds of functional food supplement increase cold-induced thermogenesis (CIT) through upregulating uncoupling protein 1 (UCP1) in BAT deposits. [Purpose] The purpose of this study was to elucidate whether habitual exercise training was associated with increased BAT content and whether supplementation of grains of paradise (GP), a West African spice in the ginger family, increased BAT content and CIT. [Methods] We measured BAT parameters (tissue total-hemoglobin) at the supraclavicular region using near-infrared time-resolved spectroscopy in 7 collegiate healthy non-athletic individuals, 8 swimmers, and 8 triathletes. BAT content was higher in swimmers and triathletes than in healthy non-athletic individuals. The effects of GP intake (40mg/day for 4 weeks) were examined in a double-blind placebo-controlled design in 18 healthy individuals. We did not find any significant effects of GP intake on any parameters. However, individuals with the lower BAT content and blunted CIT response pre-intervention showed a greater increase in BAT content and CIT post-intervention. The results of this study indicate that habitual exercise training and adequate functional food intake, specifically for individuals with the lower BAT content and blunted CIT response, could increase BAT content and enhance thermogenesis, presumably reducing risk factors for developing life-style related diseases.

DESCENTE SPORTS SCIENCE Vol.36/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE