Acute effects of mustard, horseradish, black pepper and ginger on energy expenditure, appetite, ad libitum energy intake and energy balance in human subjects.
Level 2 - randomized trial
Randomized, single-blind, placebo-controlled crossover trial
PubMed 23021155 · doi:10.1017/S0007114512001201
What was done
In a five-way, placebo-controlled, single-blind, crossover trial, 22 young (mean age 24.9 ± 4.6 years), normal-weight (mean BMI 21.8 ± 2.1 kg/m²) males were randomly assigned to consume a test brunch meal containing black pepper (1.3 g), ginger (20 g), horseradish (8.3 g), mustard (21 g), or no spice (placebo). The primary outcome was 4-hour postprandial diet-induced thermogenesis (DIT). Secondary outcomes included subjective appetite measures, ad libitum energy intake, energy balance, heart rate, and blood pressure.
What was found
No statistically significant treatment effects were observed for 4-hour DIT across the spices, although mustard showed a non-significant trend toward increased DIT versus placebo (14% increase, 59 ± 3 vs. 52 ± 2 kJ/h; P = 0.08). Black pepper, ginger, and horseradish showed no thermogenic effects approaching significance. Subjective appetite ratings (P > 0.85), ad libitum energy intake (P = 0.63), and energy balance (P = 0.67) did not differ between conditions. Horseradish significantly decreased heart rate (P = 0.048) and increased diastolic blood pressure (P = 0.049) compared with placebo.
Why it matters
While chili peppers frequently demonstrate mild thermogenic effects, other common pungent spices at palatable culinary doses do not meaningfully alter acute metabolic rate, subjective appetite, or short-term calorie intake in healthy individuals.
Limits
The study was small (22 participants) and included only young, normal-weight males, limiting generalizability to females, older adults, and individuals with overweight or obesity. It evaluated single-meal acute responses rather than sustained daily consumption, and the single-blind design may leave subjective appetite ratings vulnerable to subtle detection of spices.