Back pain is one of the leading causes of disability in the United States. It is estimated that every 8 out of 10 Americans experience back pain at some point in their lives. As per reports from the American Chiropractic Association, this is one of the main reasons for missed days work and the second most common reason for doctor’s visits. In fact, more than 31 million Americans experience this condition at any given time. A new study published in the medical journal Human Brain Mapping reports that people who smoke are more likely to develop chronic back pain than those who do not smoke.
The study conducted by researchers from the Northwestern University in Evanston, IL reports that smoking interferes with a brain circuit associated with pain and this makes smokers more prone to this chronic condition. It suggests that people could possibly lower their risk of developing this condition by quitting the smoking habit.
As part of the research, the participants were divided into 3 groups. Researchers studied about 160 participants who suffered from sub acute back pain (defined as ache lasting for 4 to 12 weeks with no traces of the same in the previous year) over one year. Out of these, 123 were recruited to the study and 68 people completed follow-up after one year. The second group evaluated 32 participants with chronic back ache (defined as having ache for 5 years or more), out of which 24 people completed the study. The third group included 35 participants with no back ache and only 19 people completed the study.
The survey participants completed well validated questionnaires relating to information about their level of pain, depression, positive or negative feelings and emotions, smoking status and other serious health conditions. After an initial visit, the participants were accessed during four more occasions using further questionnaires. In addition, they underwent four functional magnetic resonance imaging (MRI) brain scans over the course of one year. The MRI scans were done to evaluate the level of activity between two brain regions namely the nucleus accumbens and the medial prefrontal cortex which play an active role in addictive behavior and motivated learning. The key findings of the research are mentioned below –
- In the first group that included 68 people with sub acute back pain, 31 (6 people were smokers and 25 were non-smokers) had experienced around 20% decrease in this condition after one year. The other 37 people (16 smokers and 21 non-smokers) suffered continuous pain.
- People who experienced persistent aches were three times more likely to be smokers than others who recovered.
- It was found that smokers had increased activity in the brain pathways (between the nucleus accumbens and the medial prefrontal cortex) and this may increase their risk of back ache.
- A dramatic drop was found in the brain pathway activity in smokers who had quit smoking as part of the study and this reduced their risk for acute backache.
The research findings signify that smoking significantly affects brain circuitry and is directly linked to chronic pain. Researchers found that those smoking participants who managed this condition by consuming medications such as anti-inflammatory drugs did experience certain level of reduction in pain, but this could not alter brain circuitry. Researchers suggest that smokers could potentially reduce their risk of this condition by engaging themselves in smoking cessation programs or other behavioral interventions that will help them to quit their smoking habits permanently.