Capsinoids or non-pungent extracts from chilli plants have been shown to have thermogenic effects on metabolism and reduce body weight in animals. Indeed, many commericial weight loss pills contain such extracts.
But how relevant are these effects?
This question was recently addressed by Soren Snitker and colleagues from the University of Maryland, Baltimore, MD, USA, in a study just published in the American Journal of Clinical Nutrition.
Snitker et al. conducted a 12-wk, placebo-controlled, double-blind, randomized study of oral capsinoids (6 mg/d) in 40 men and 40 women. They measured changes in body weight, body fat (DEXA) and metabolism (indirect calorimetry). They also performed some genetic analyses.
Capsinoids were well tolerated but did not markedly affect body wieght (0.9 kg on capsinoids vs. 0.5 kg on placebo). Total body fat was unchanged but there was a marginal (1.1%) reduction in abdominal adiposity with capsaicin. While changes in resting energy expenditure did not differ between groups, fat oxidation was a tick higher at the end of the study in the capsinoid group. Of 13 genetic variants tested, TRPV1 Val585Ile and UCP2 -866 G/A correlated significantly with change in abdominal adiposity.
Although the authors appear quite enthusiastic about their findings, I consider this essentially a negative study. Neither the few grams of weight loss nor the skimpy increase in fat oxidation are likely to be of any clinical relevance. The study is vastly underpowered for any meaningful genetic analyses.
I will certainly continue enjoying my hot sauce – but will stop kidding myself that this indulgence in anyway contributes to managing my weight.