Before the advent of anesthesia, patients undergoing surgery were often given copious amounts of alcohol to help make them more comfortable. But is there any scientific proof that alcohol can actually dull pain, or is the person simply too drunk to care? Surprisingly, previous studies on this topic have been mixed, so these researchers performed a meta-analysis to get to the bottom of the matter. By systematically reviewing 18 studies on over 400 subjects, they found that yes, alcohol not only dulls pain, it also increases pain tolerance. How much alcohol does the trick? A blood alcohol content (BAC) of 0.08% (legally drunk, 3-4 drinks) produces a statistically significant reduction in pain intensity and an increase in pain threshold, and increasing BAC augmented these levels even further. Something to consider the next time you have to perform surgery in the 18th century. Cheers!
“Despite the long-standing belief in the analgesic properties of alcohol, experimental studies have produced mixed results. This meta-analysis aimed to clarify whether alcohol produces a decrease in experimentally-induced pain and to determine the magnitude of any such effect. PubMed, PsycINFO, and Embase databases were searched from inception until April 21, 2016 for controlled studies examining the effect of quantified dosages of alcohol on pain response to noxious stimulation. Eighteen studies involving 404 participants were identified providing alcohol versus no-alcohol comparisons for 13 tests of pain threshold (n = 212) and 9 tests of pain intensity ratings (n = 192). Random effects meta-analysis of standardized mean difference (SMD) provided robust support for analgesic effects of alcohol. A mean blood alcohol content (BAC) of approximately .08% (3–4 standard drinks) produced a small elevation of pain threshold (SMD [95% CI] = .35 [.17–.54], P = .002), and a moderate to large reduction in pain intensity ratings (SMD [95% CI] = .64 [.37–.91], P < .0001), or equivalently, a mean reduction of 1.25 points on a 0- to 10-point pain rating scale. Furthermore, increasing BAC resulted in increasing analgesia, with each .02% BAC increment producing an increase of SMD = .11 for pain threshold and SMD = .20 for reduced pain intensity. Some evidence of publication bias emerged, but statistical correction methods suggested minimal impact on effect size. Taken together, findings suggest that alcohol is an effective analgesic that delivers clinically-relevant reductions in ratings of pain intensity, which could explain alcohol misuse in those with persistent pain despite its potential consequences for long-term health. Further research is needed to corroborate these findings for clinical pain states.”