Eating spicy food can alter pain perception

Spicy stimulation appears to trigger an analgesic effect that lasts beyond the taste stimulus, a recent study has found. In contrast, keeping a long-term spicy diet may instead lower the threshold for basal pain sensitivity.

Sixty healthy undergraduate volunteers (aged 20–35 years; 50 percent female) were enrolled in this study. Pressure pain (PPT) and cold pain (CPT) thresholds after taste stimulation with spicy gelatin were compared with values before stimulation and during placebo stimulation. The analgesic effect of sweet stimulation was used as a reference.

The spicy taste stimulus significantly increased the PPT to 13.1±4.0 kg/cm² just 3 minutes after stimulation. Relative to the baseline threshold of 11.0±3.4 kg/cm², this represented a statistically significant increase. The spike in PPT remained stable and significant up to 10 and 17 minutes after stimulation.

Similarly, CPT increased significantly after spicy stimulation, jumping to 6.3±3.6, 6.2±3.1, and 6.7±3.6 seconds at 3, 10, and 17 minutes relative to the threshold of 5.3±3.3 seconds at baseline. Significant analgesia was also reported after sweet stimulation except for the first and second timepoints for the CPT challenge.

Using a food frequency questionnaire, the researchers found that participants who consumed spicy food ≥3 days per week had significantly lowered PPT and CPT than comparators with spicy intake <3 days per week. This was confirmed in a separate validation cohort, where the frequency of spicy food consumption was significantly and inversely correlated with PPT (p=0.013) and CPT (p=0.035).

“[T]his study illuminated that a long-term spicy diet has an impact on human basic pain sensitivity and that it has the opposite effect relative to immediate spicy stimuli. However, the mechanism underlying this phenomenon remains unclear,” the researchers said.