If you are one of the millions of Americans who suffer from chronic pain conditions like low back pain there is a good chance you are desperate for answers. Chronic pain conditions are notoriously difficult to treat and patients are often left feeling frustrated and, well, in pain.
Can Chemicals Cause Back Pain?
New research on low back pain has recently revealed some interesting connections between certain chemicals in our bodies and how we experience pain. In this article we are going to look at a chemical called BDNF (Brain Derived Neurotropic Factor) and the role that it plays in chronic pain. We are also going to look at ways that you can manage BDNF and how you can potentially address your chronic pain from a unique perspective.
What Is Chronic Pain?
Before we can look at how to address chronic pain, it is helpful to know what it is, exactly. Chronic pain is generally defined as “pain that has lasted for more than 3 to 6 months after an injury should have healed". Pain is also considered to be chronic if it keeps recurring.
The International Association of Pain classified chronic pain to 2 categories:
chronic primary pain and
chronic secondary pain.
Conditions like chronic primary musculoskeletal pain (like low back pain) and chronic widespread pain (eg. fibromyalgia) are two examples of chronic primary pain.
Understanding Chronic Widespread Pain (CWP)
The American College of Rheumatology defined chronic widespread pain (CWP) as “pain that lasts more than 3 months, located above and below the waist, and on both sides of the body”. The definition has also been updated to include physical symptoms like fatigue and waking unrefreshed. Chronic widespread pain is often associated with conditions like fibromyalgia.
Osteoarthritic Pain
Osteoarthritis (OA) is another type of chronic pain disorder. OA is a chronic and progressive degenerative joint disease that occurs when the protective cartilage that cushions the ends of the bones wears down over time. OA can affect any of the joints but the most common joints affected generally include hands, hips, knees, and spine.
What Is Neuroplasticity And How Does BDNF Fit In?
Now that we know what chronic pain is and what conditions it is associated with, we can look at what causes it.
Neuroplasticity is a term that refers to the ability of the nervous system to change how it works in response to certain internal or external stimulations like injuries or trauma. Researchers have been investigating how chronic pain can come about when our nervous systems respond to injuries in the wrong way - particularly when it comes to low back pain, osteoarthritis, and fibromyalgia.
Certain hormones, known as neurotrophins, control how our nervous systems work. One of these hormones is BDNF. BDNF is an important member of the neurotrophin family and it is essential for the healthy development of our nervous system and in neuroplasticity.
The Link Between BDNF And Inflammation
Inflammation is something that is often associated with chronic pain, and research has uncovered a link between inflammation and BDNF. There is growing evidence that inflammation and BDNF influence each other with important outcomes.
When inflammation levels are high in the body, BDNF tends not to be produced as much, while BDNF has been found to play an important reciprocal role in regulating inflammation levels in the brain. The production of BDNF is highly regulated in the body and there can be a lot of variation in levels between one person and another.
The Link Between BDNF, Inflammation, and Back Pain
Research has shown that there is a unifying theory or law of pain that states that “the origin of all pain is inflammation and the inflammatory response’.
It doesn’t matter what type of pain you are experiencing, acute or chronic, the underlying cause of that pain is almost always going to be inflammation and the inflammatory response. The entire process from the activation of pain receptors to the transmission of pain signals (as well as neuroplasticity) is all just one long continuum of inflammation and pain.
What does that mean for low back pain? Well, most cases of back and neck pain occur as a result of an injury to the muscles, discs, ligaments, joints or nerves. This injury results in inflammation which is basically the start of when you feel pain. When it comes to disc degeneration or a herniated disc, the same inflammation process occurs as with an injury.
BDNF Levels In Chronic Pain Patients
It is a well known fact that BDNF levels are different in chronic pain patients compared to healthy subjects. Data has shown that BDNF levels are lower in patients with osteoarthritis but higher in those with fibromyalgia.
One study that looked specifically at serum levels of BDNF in healthy patients compared to pain patients found that the ‘levels of both free and total BDNF’ were ‘significantly lower in pain patients compared to healthy subjects’. This means that if we know BDNF levels are low in chronic pain patients, increasing those levels may help reduce the pain and inflammation in low back patients.
It also helps us to know that changes in how much BDNF is produced/expressed are often associated with psychiatric diseases like depression, as well as pathological aging so that those issues can be addressed.
How BDNF Is Connected To Mental Health
While we know about the link between inflammation and BDNF, there is also growing evidence to show that BDNF plays a role in mental health conditions like depression and anxiety, which are often also associated with chronic pain patients.
Low back pain patients, as well as chronic pain patients, often suffer from psychological symptoms like depression, anxiety, loneliness and sleep deprivation. Studies have found that the levels of BDNF are different, not only in chronic pain patients, but also in those suffering from major depression.
A study of patients in Macedonia and Bulgaria in 2013 confirmed that ‘low serum levels of BDNF are a state of abnormality that is evident during depression’.
What Causes BDNF Levels To Decrease?
Inflammation:
Since we already know that there is a two way relationship between BDNF and inflammation, it isn’t really much of a surprise to find out that inflammation, and things like stress, that trigger inflammation can cause BDNF levels to drop.
Inflammation is often a consequence of the immune system’s activation in response to an irritant or loss of homeostatic control due to factors such as stress, obesity, and aging, to trauma or injury.
Stress:
Prenatal, early life, social, and unpredictable stress are all associated with reduced BDNF expression.
Age:
Getting older is another factor that has been connected with decreasing levels of BDNF, with hippocampal atrophy (an indicator of Alzheimer’s Disease) being a further complication and influencing factor. Low BDNF levels are associated with other age-related neurodegenerative disorders like Parkinson’s disease.
Exercise:
A lack of exercise has been linked to lower levels of BDNF.
Diet:
BDNF has also been linked to what we eat. Researchers have found that the typical western diet that is high in carbohydrates and fat decreases levels of BDNF found in the brain (hippocampus).
How Can You Increase BDNF?
Knowing your BDNF levels are low, and knowing the types of things that can affect your levels also means that we can know how to fix them and increase them.
Reduce Stress:
Taking steps to reduce stress levels can also help reduce inflammation in the body. Therapeutic practices like mindfulness, deep breathing and meditation can help to control stress levels and help curb inflammation levels in the body.
Antidepressants:
Studies have found that certain antidepressants can help to increase levels of BDNF in the body, which is why data have shown that BDNF levels increase after antidepressant treatment.
Diet:
Research has shown that a carbohydrate-restricted diet, like Keto diets or Paleo diets, can increase serum BDNF levels.
Exercise:
Physical exercise has consistently increased levels of BDNF. The research has gone further to identify that this is intensity dependent. A small study of 12 people conducted in 2019 found that those who engaged in HIIT (High Intensity Interval Training) experienced greater increases in BDNF levels than those who engaged in moderate intensity exercise.
TLDR:
BDNF is a hormone that our bodies produce that works directly on inflammation in our bodies. We know that inflammation is caused by things like trauma, injury or stress. Inflammation is a condition that often causes back pain.
Stress, depression, a poor diet, and a lack of exercise can often cause low levels of BDNF in our bodies, and coincidentally, these are also risk factors for back pain!
When we engage in exercise, reduce stress levels, and eat more fruits and vegetables, and eat less processed foods and carbohydrates we can increase our BDNF levels as well as help reduce low back pain.
Another coincidence? Low BDNF levels have been found in people experiencing psychological challenges like depression and anxiety. Yet another risk factor for low back pain if we look at the condition from a biopsychosocial perspective.
Conclusions
Our bodies are incredible things and there is such a powerful connection between our minds and our bodies. To look at back pain from only one perspective like a trauma often doesn’t explain the pain for millions of others which is why it can be so hard to diagnose and so hard to treat, and is another reason why imaging often doesn’t show any conclusive reasons for pain.
If you are one of the millions of people who can’t seem to find a reason why you are still struggling with low back pain, despite trying dozens of different products, BDNF might be something for you to consider as at least a part of the puzzle.