Effect of chocolate preference and cocoa content on experimentally induced muscle pain

Abstract

Abstract Objectives Chocolate consumption has been associated with pain reduction, but it remains unclear whether this effect depends on cocoa concentration or individual preference. This study aimed to investigate whether chocolate preference and/or cocoa content modulate experimentally induced muscle pain in healthy men and women. Methods Thirty healthy, pain-free participants (15 men, 15 women; mean age 24.6 years) underwent three randomized, double-blind, crossover sessions separated by one-week washout periods. Pain was induced twice per session by intramuscular hypertonic saline injections into the masseter muscle, before and after ingestion of white (30% cocoa), milk (34%), or dark (70%) chocolate. Peak-pain intensity and pain-duration were assessed using a visual analogue scale. Data were analyzed using multilevel Poisson regression models accounting for repeated measures. Results Both chocolate type and individual preference significantly influenced pain outcomes. Milk chocolate produced the strongest analgesic effect, showing lower peak-pain (IRR = 0.75, 95% CI:0.64–0.88) and shorter pain-duration (IRR = 0.64, 95% CI:0.57–0.72; p < 0.01) compared with dark chocolate. White chocolate showed weaker effects for both outcomes (IRR = 1.09 and 1.11; p < 0.01). Participants’ most preferred chocolate (milk) produced greater pain-reduction than less preferred types (IRR range 0.61–0.69; p < 0.01). Chocolate composition, including sugar and cocoa content, showed no clear association with pain measures under the experimental conditions. Conclusion The analgesic effect of chocolate in this experimental setting appears to be more closely related to subjective preference and hedonic value than to cocoa concentration. Given the low dose and short exposure time, the findings primarily reflect immediate sensory-affective mechanisms rather than biochemical effects. These results suggest that reward-related processes may contribute to chocolate-induced pain modulation in acute experimental muscle pain.