Influence Of Menthol On Human Temperature Perception, Regulation And Energy Expenditure

Abstract

In humans, menthol has been shown to produce a heat storage response that may be mediated in part by brown adipose tissue activation. The purpose of this study was to examine whether Menthol produces a cooling sensation, influences temperature regulation, and alters energy expenditure. To test this, seventeen healthy male participants (n = 17) between the ages of 18 and 35 were recruited to take part in this repeated-measures investigation. Participants rested supine in a temperature-controlled environment of 30℃ and 50% relative humidity. Participants rested for 30 minutes prior to Menthol or placebo gel application to establish a baseline temperature and metabolic value. A placebo gel with no Menthol and a 4.13% Menthol containing dose (Biofreeze, Performance Health, Warrenville, IL, USA) were applied to the anterior surface of each participant while they rested in the supine position at the 30-minute mark and measures were collected until the 60-minute mark. Measures collected were deep body temperature (Tre), RER, absolute VO2, relative VO2, supraclavicular skin temperature, skin blood perfusion, and thermal sensation. A one-tailed T-test and also a two tailed T-test (for metabolic data) were used to test for significance. Several measures did not show a significant response to Menthol, however, the reason for this remains unclear. The two values that showed a significant response to Menthol were deep body temperature and thermal sensation, suggesting that the Menthol containing dose had an effect on thermal sensation as well as some effect on temperature regulation. Menthol appears to cause the body to perceive that it is cooler than it is (lower thermal sensation score), while simultaneously causing it to store more heat (rectal temperature elevation). Despite the insignificant findings of several of the measures, the alternative hypothesis that Menthol produces a change in temperature perception and thermoregulation can be supported, and the hypothesis that menthol will cause no change in energy expenditure cannot be rejected.