Effects of Spicy Stimulation and Spicy-Food Consumption on Human Pain Sensitivity: A Healthy Volunteer Study

Effect of noise isolation using noise-cancelling headphones during laparoscopic surgery for postoperative pain reduction: A randomized clinical trial

STUDY OBJECTIVE

Most laparoscopic surgeries under general anesthesia are performed in noisy environments, although the effect of intraoperative noise reduction on postoperative pain remains uncertain. This study aimed to explore whether postoperative pain could be reduced through the intraoperative use of noise-cancelling headphones.

DESIGN

This study was conducted as a prospective parallel-group randomized clinical trial.

SETTING

Operating room and surgery room.

PATIENTS

Ninety patients who underwent laparoscopic surgery under general anesthesia.

INTERVENTIONS

In the intervention group, noise-cancelling headphones were used to reduce noise intensity during laparoscopic surgery under general anesthesia.

MEASUREMENTS

The primary outcome was the maximum movement-evoked pain intensity within 24 h post-surgery, measured using a 10-point numeric rating scale. Secondary outcomes included the maximum resting pain score and total opioid consumption during the 24-h period post-surgery. Mean intraoperative noise and the proportion of intraoperative time with noise intensity ≥70 dB were recorded.

MAIN RESULTS

The maximum movement-evoked pain score was significantly lower in the intervention group than in the control group (mean score [SD], 2.7 [1.0] and 4.0[1.0], respectively; P < 0.001). The intervention group required significantly fewer opioids than the control group (mean [SD], 44.2 [12.8] and 51.3[17.5] mg, respectively; P = 0.032). In the control group, but not the intervention group, all postoperative pain scores were significantly associated with the proportion of intraoperative time with noise intensity ≥70 dB, which was an independent risk factor for postoperative pain.

CONCLUSION

During laparoscopic surgery under general anesthesia, intraoperative noise isolation using noise-cancelling headphones is a safe and effective strategy for relieving postoperative pain and decreasing total opioid analgesic consumption.

Neural mechanisms of priming effects of spicy food pictures induced analgesia

In this study, the effects of the priming of spicy food pictures on pain perception were evaluated in female participants using standardized methods of pain. Results from behavior tests revealed that the priming of spicy food pictures significantly reduced pain perception, particularly at high-pain intensities. Electrophysiological analysis showed that the analgesic effects of spicy food pictures were linked to decreased pain-related event-related potentials, such as N2 and P2 amplitudes, and suppressed θ-oscillations in the sensorimotor cortex. Both N2 amplitudes and θ-oscillations activities were found to be correlated with participants' pain perception. These results suggest that spicy-arousal stimuli may act as an "antagonist" to the increase in N2 amplitudes and θ-oscillations power induced by pain and influence the neuronal networks involved in integrating spontaneous nociceptive resources, which supports the dissociation theory of pain sensation and affection. These findings highlight the potential use of spicy-arousal stimuli as an analgesic and emphasize the importance of considering both the intensity of the stimuli and the individual's emotional state in the assessment and treatment of pain.

Effects of spicy food consumption on overweight/obesity, hypertension and blood lipids in China: a meta-analysis of cross-sectional studies

BACKGROUND AND OBJECTIVES

Effect of spicy food consumption on health has attracted widespread attention in recent years. However, the relationships between spicy food intake and overweight/obesity, hypertension and blood lipid levels remain unclear. A meta-analysis of available observational studies was conducted in order to explore the associations.

METHODS

PubMed, Embase, Cochrane Library and Web of science databases were searched for studies published up to 10 August 2021 without language limitation. The fixed and random effects models were selected to aggregate the effect sizes and 95% confidence intervals (CIs) in this study.

RESULTS

A total of nine observational studies involving 189,817 participants were included. Results from this meta-analysis showed that the highest category of spicy food intake significantly increased the risk of overweight/obesity (pooled Odds Ratio (OR): 1.17; 95% CI: 1.07, 1.28; P < 0.001), compared with the lowest category of spicy food intake. Conversely, a remarkable negative association was observed between the highest category of spicy food intake and hypertension (pooled OR: 0.87; 95% CI: 0.81, 0.93; P = 0.307). In addition, the highest category of spicy food intake increased the level of low density lipoprotein cholesterol (LDL-C) (weighted mean difference (WMD): 0.21; 95% CI: 0.02, 0.39; P = 0.040), and reduced high density lipoprotein cholesterol level (HDL-C) (WMD: -0.06; 95% CI: -0.10, -0.02; P = 0.268) concentrations, but it was not related to total cholesterol (TC) (WMD: 0.09; 95% CI: -0.08, 0.26; P = 0.071) and triglyceride (TG) (WMD: -0.08; 95% CI: -0.19, 0.02; P = 0.333)] levels.

CONCLUSION

Spicy food intake may have a beneficial effect on hypertension, but adversely affect overweight/obesity, as well as blood lipid levels. However, the results should be interpreted cautiously because the present analyses were based on only observational studies and not intervention studies. More large and high-quality studies in different populations will be needed to verify these associations in the future.

The Association Between Long-Term Spicy-Food Consumption and the Incidence of Chronic Postsurgical Pain After Cesarean Delivery: An Observational Study

Background

Our previous study found that a long-term diet incorporating spicy foods can reduce the human basal pain threshold. Capsaicin is the pungent ingredient in chili peppers. Transient receptor potential vanilloid type1 is the capsaicin receptor expressed in the oral cavity and is the primary sensory neuron of the “pain” pathway. Few studies have examined the association between long-term spicy diet and chronic postsurgical pain (CPSP). Women who underwent elective cesarean section (eCS) have consistent characteristics of CPSP. This study aimed to investigate the relationship between a long-term spicy diet and the incidence of CPSP after eCS.

Methods

Participants were divided into a low frequency group (LF, numerical rating scale (NRS)<5) for spicy food consumption and a high frequency group (HF, NRS≥5) by receiver operator characteristic analysis. The primary outcome was the incidence of CPSP three months after eCS. Propensity score matching (PSM) analysis was performed between the two frequency groups. Stepwise logistic regression analysis was then performed.

Results

Of the 1029 enrolled patients, data from 982 were analyzed 3 months after eCS. After PSM, the incidence of CPSP in the HF group (30.1% [108/359]) was higher than that in the LF group (19.8% [71/359]; P = 0.001). Compared with the LF group, the risk of CPSP in the HF group increased 1.61 times by 3 months (95% CI 1.18–2.20, P = 0.003). PSM results found that 1 year, the incidence of CPSP in the HF group (15.2% [56/369]) was higher than that in the LF group (8.1% [30/369], P = 0.003).

Conclusion

With an NRS≥5 as a boundary, women who consumed spicy food ≥ 2 days/week were more likely to have CPSP than those who consumed spicy food < 2 days/week.

Role of daytime variation in pharmaceutical effects of sufentanil, dezocine, and tramadol: A matched observational study

The role of daytime variation in the comprehensive pharmaceutical effects of commonly used opioid analgesics in clinical setting remains unclear. This study aimed to explore the differences in daytime variation among elective surgery patients who were scheduled to receive preemptive analgesia with equivalent doses of sufentanil, dezocine, and tramadol in the morning and afternoon. The analgesic effect was assessed by changes in the pressure pain threshold before and after intravenous administration of sufentanil, dezocine, and tramadol. Respiratory effects were evaluated using pulse oximetry, electrical impedance tomography, and arterial blood gas analysis. Other side effects, including nausea, sedation, and dizziness, were also recorded, and blood concentration was measured. The results showed that the analgesic effects of sufentanil, dezocine, and tramadol were significantly better in the morning than in afternoon. In the afternoon, sufentanil had a stronger sedative effect, whereas dezocine had a stronger inhibitory respiratory effect. The incidence of nausea was higher in the morning with tramadol. Additionally, significant differences in different side effects were observed among three opioids. Our results suggest that the clinical use of these three opioids necessitates the formulation of individualized treatment plans, accounting for different administration times, to achieve maximum analgesic effect with minimal side effects.

The Biology of BDSM: A Systematic Review

INTRODUCTION

BDSM is an abbreviation used to reference the concepts of bondage and discipline, dominance and submission, sadism and masochism, enacted by power exchanges between consensual partners. In recent years, attention has shifted from the idea of BDSM as a pathological and tabooed niche practice towards viewing BDSM as a healthy form of intimacy.

AIM

This systematic review brings together all existing literature on the biology of BDSM and places it in a broader biological context.

METHODS

A systematic search was conducted on PubMed, Web of Science and PsycARTICLES, of which 10 articles are included and discussed in this systematic review.

RESULTS

There is evidence for cortisol changes in submissives as a result of a BDSM interaction, suggesting involvement of the physiological stress system. Endocannabinoid changes implicate the pleasure and reward system. In dominants, this biologically measured pleasure seemed to be dependent on power play rather than pain play. Testosterone and oxytocin are also implicated in BDSM, though their role is less evident. Research into brain region activity patterns related to BDSM interest suggests a role for the parietal operculum and ventral striatum in the context of the pleasure and reward system, the primary and secondary somatosensory cortex in the context of pain perception, empathy-related circuits such as the anterior insula, anterior midcingulate cortex and sensorimotor cortex and the left frontal cortex in the context of social and sexual interactions. Pain thresholds are shown to be higher in submissive individuals and a BDSM interaction may cause pain thresholds to rise in submissives as well.

CONCLUSION

BDSM interactions are complex and influenced by several psychological, social and biological processes. Though research is limited, there is emerging evidence for an interaction between several biological systems involved in these types of interests and activities. This means there is an important role for future research to replicate and supplement current results.

Pain, Smell, and Taste in Adults: A Narrative Review of Multisensory Perception and Interaction

Every day our sensory systems perceive and integrate a variety of stimuli containing information vital for our survival. Pain acts as a protective warning system, eliciting a response to remove harmful stimuli; it may also be a symptom of an illness or present as a disease itself. There is a growing need for additional pain-relieving therapies involving the multisensory integration of smell and taste in pain modulation, an approach that may provide new strategies for the treatment and management of pain. While pain, smell, and taste share common features and are strongly linked to emotion and cognition, their interaction has been poorly explored. In this review, we provide an overview of the literature on pain modulation by olfactory and gustatory substances. It includes adult human studies investigating measures of pain threshold, tolerance, intensity, and/or unpleasantness. Due to the limited number of studies currently available, we have structured this review as a narrative in which we comment on experimentally induced and clinical pain separately on pain–smell and pain–taste interaction. Inconsistent study findings notwithstanding, pain, smell, and taste seem to interact at both the behavioral and the neural levels. Pain intensity and unpleasantness seem to be affected more by olfactory substances, whereas pain threshold and tolerance are influenced by gustatory substances. Few pilot studies to date have investigated these effects in clinical populations. While the current results are promising for the future, more evidence is needed to elucidate the link between the chemical senses and pain. Doing so has the potential to improve and develop novel options for pain treatment.