University of Greenwich’s Trevor Thompson led the review study that looked at 18 different experiments which tested the reactions of more than 400 healthy people. Their reactions were measured when exposed to controlled pain (such as heat, cold and pressure) both without alcohol and under the influence of alcohol.
Thompson concluded that there is “robust evidence that alcohol is an effective painkiller.”
“Although the finding that alcohol results in reduced pain might seem obvious to many people, results from individual studies have not actually been that consistent,” Thompson wrote in an email.
His team systematically evaluated the different results in previous studies and were able to “reliably conclude” that alcohol is an analgesic. They were also able estimate the amount of pain relief a certain dosage of alcohol provides.
For example, they found that around two pints of beer or two medium-sized glasses of wine resulted in a 24 per cent drop in pain ratings. And the higher the blood-alcohol level, the greater the pain relief (up to a blood-alcohol level of .11).
It’s still a mystery as to why alcohol produces these painkilling effects, although Thompson has a couple of ideas.
“Some have theorised that alcohol may work indirectly by reducing anxiety, which is likely to be linked to pain,” he said. “Others have suggested that the transmission of ‘pain signals’ is inhibited by the changing of activity NMDA receptors in the spinal cord.”
NMDA receptors are a protein found in nerve cells.
Researchers think that these results may shed some light on alcohol dependency for those with chronic pain.
“There could be a number of potential reasons why chronic pain patients might become alcohol dependent, including as a coping strategy response to tackle anxiety or depression, a general lifestyle change due to restricted mobility from persistent pain,” explained Thompson.
He added that because alcohol does provide significant pain relief, it offers a “reward,” which may encourage pain sufferers to turn to the bottle since it is generally cheaper and more accessible than prescription medications.
He hopes that in the future, drug producers may be able to isolate specific compounds found in alcohol that provide the analgesic effects, without the harmful side effects of alcohol.
“The amount of alcohol consumption needed to provide any sort of sustained, long-term pain relief could lead to a range of serious health problems, and even increase the likelihood of developing a longterm persistent pain condition,” he said. “We hope than an increased awareness of this might lead to greater promotion of alternative, less harmful pain management strategies for those using alcohol as self-medication for pain.”