Chiropractic care is focused on the treatment of musculoskeletal conditions such as back pain, neck pain and joint stiffness. Over the past decade however, research interest has gradually looked beyond pain outcomes alone, exploring how spinal care may influence broader physiological systems — particularly the nervous system, immune signalling, and the body’s stress response.
One emerging area of research looks not at symptoms, but at biological markers that reflect how the brain and immune system are functioning. These biomarkers offer a more objective window into physiological regulation, adaptation and recovery. A recent 12-week randomized controlled trial[i], with follow up at 16 weeks, examined adults ranging from 20 – 60 years with subclinical spinal pain to investigate how chiropractic care may influence markers related to neuroplasticity, inflammation, and stress regulation, compared with a sham (control) intervention.
Importantly, the participants in this research were not people with severe injury or acute pathology. Instead, they represented a common clinical group — individuals with recurring stiffness, tension, or low-grade spinal discomfort who often remain active but feel “not quite right.”
What follows is a careful discussion of what this research found, what it suggests, and what it does not claim.
Neuroplasticity: Supporting the Brain’s Capacity to Adapt
At the centre of the study’s neurological findings is Brain-Derived Neurotrophic Factor (BDNF). BDNF is a protein that plays a key role in the health and adaptability of the central nervous system. It supports synaptic plasticity — the ability of neurons to strengthen, weaken, and reorganise their connections — which underpins learning, motor control, sensory processing, and recovery from stress.
After 12 weeks of chiropractic care, participants showed significantly higher blood levels of BDNF compared with the sham group. This difference was not observed in those receiving the control intervention.
Reduced BDNF levels have been associated in other research with chronic stress exposure, persistent inflammation, and reduced neural adaptability. Conversely, higher BDNF availability is thought to support the brain’s capacity to respond to changing physical and environmental demands.
It is not suggested that spinal adjustments “treat the brain”, but that mechanical input from the spine provides a meaningful sensory stimulus. This recent study suggests that spinal manipulation may promote neuroplasticity in the central nervous system and enhance nervous system function.
Inflammation: Shifting the Balance Toward Regulation
Inflammation is a normal and necessary part of tissue repair and immune defense. Problems arise when inflammatory signalling becomes excessive, prolonged, or poorly regulated. Chronic low-grade inflammation has been linked to musculoskeletal pain, fatigue, metabolic disorders, and altered nervous system function.
In this trial, several inflammatory markers were measured over time. Two findings stood out.
First, participants receiving chiropractic care demonstrated lower levels of Tumour Necrosis Factor-alpha (TNF-α) at both 12 and 16 weeks compared with the sham group. TNF-α is a pro-inflammatory cytokine commonly associated with persistent inflammatory states. Levels of Interferon-gamma (IFN-γ) were also lower in the chiropractic group at the 16-week follow-up.
In contrast, the sham group showed a steady rise in these inflammatory markers over the same period, suggesting that without meaningful mechanical or neurological input, inflammatory signalling may continue to drift upward in people with ongoing spinal discomfort.
Second, the chiropractic group demonstrated higher levels of Interleukin-6 (IL-6) after 12 weeks. At first glance, this could appear contradictory, as IL-6 is often labelled as a pro-inflammatory marker. However, context matters.
IL-6 can act in different roles depending on how and where it is released. When produced by skeletal muscle in response to mechanical loading or contraction, IL-6 behaves as a myokine — a signalling molecule that supports tissue repair, metabolic regulation, and local immune balance. The authors suggest that the IL-6 increase observed here likely reflects muscle-derived signalling from deep paraspinal tissues responding to high-velocity, low-amplitude spinal adjustments.
In this context, IL-6 may be acting not as a driver of systemic inflammation, but as part of a coordinated repair and adaptation response.
Stress, Cortisol, and the Regulatory Loop
The body’s stress response provides a critical link between neuroplasticity and inflammation. Cortisol, a hormone released through activation of the hypothalamic-pituitary-adrenal (HPA) axis, plays a central role in managing inflammation and energy availability. However, chronically elevated cortisol can impair immune function, disrupt sleep and negatively affect brain health.
In this study, participants receiving chiropractic care showed a temporary rise in salivary cortisol at 12 weeks, which the authors interpret as a normal physiological response to mechanical input. This is not unexpected; physical interventions, including exercise and manual therapy, can transiently activate stress pathways.
What is more notable is what happened next. At the 16-week follow-up — four weeks after chiropractic care had ended — blood cortisol levels were significantly lower in the chiropractic group compared with the sham group. This suggests that while short-term stress responses occurred, longer-term systemic stress regulation may have improved.
Interpreting the Findings Carefully
It is important to be clear about what this research does and does not show.
This study does not claim that chiropractic care:
- Treats neurological disease
- Cures inflammation-related conditions
- Permanently alters brain structure
- Replaces medical management for systemic illness
What it does suggest is that chiropractic care may influence measurable physiological processes involved in neural adaptation, immune signalling, and stress regulation — particularly in people with persistent, low-grade spinal dysfunction.
These findings align with a growing understanding of the spine as a sensorimotor interface, rather than simply a mechanical structure. How the spine moves, loads, and transmits sensory information appears to matter in terms of how the nervous system and immune system coordinate their responses.
Clinical Relevance for Patients
The researchers concluded that chiropractic spinal care may influence neuroplasticity, stress, and inflammatory pathways. While the effects were modest, the results provide preliminary evidence that improving spinal function is not just about pain reduction. Changes in movement quality, coordination, and load tolerance may influence how the body regulates itself more broadly. Larger and longer-term trials are needed to confirm these findings and to clarify their clinical relevance.
This does not mean everyone needs long-term care, nor does it justify over-treatment. Rather, it supports the idea that appropriately applied, evidence-informed chiropractic care may have effects beyond symptom relief, particularly when combined with movement, exercise, and healthy lifestyle behaviours.
If you are dealing with recurring spinal tension, pain or stiffness that never quite resolves, or if you wish to discuss this study further, our chiropractors are here to help. To speak to us or make an appointment, please call us on (07) 5580 5655 or visit our website.
[i] Amjad I, Niazi IK, Kumari N, Ghani U, Rashid U, et al. (2025) The effects of 12 weeks of chiropractic spinal adjustments on physiological biomarkers in adults: A pragmatic randomized controlled trial. PLOS ONE 20(12): e0338730. https://doi.org/10.1371/journal.pone.0338730
