Most people come to a chiropractor because something hurts — their back, their neck, a nagging headache. And chiropractic adjustments are excellent at helping with those things. But what if the benefits go deeper than just pain relief? What if regular chiropractic care is actually changing the way your body heals, handles stress, and fights off illness at the cellular level?
A groundbreaking study published in December 2025 in the journal PLOS ONE set out to answer exactly that question. And the results are worth talking about.
You may have heard a chiropractor claim that an adjustment can help reduce stress and boost the immune system. Here's data and evidence from a rigorous clinical trial to support that claim.
The study at a glance
Researchers from the Centre for Chiropractic Research (New Zealand College of Chiropractic), Riphah International University (Pakistan), and several other institutions conducted a randomized controlled trial — the gold standard of scientific research. Here's what they did:
- 106 adults with recurring spinal aches and pain were randomly split into two groups
- One group received real chiropractic adjustments approximately three times per week for 12 weeks
- The other group received sham (fake) chiropractic care — they went through the motions of a visit, but no actual adjustments were delivered
- Blood, saliva, and hair samples were collected at three points: before treatment, after 12 weeks, and again at 16 weeks (a month after care stopped)
- Over 94% of participants in both groups believed they received real care, meaning the placebo effect was well controlled
Because participants couldn't tell the difference between real and fake adjustments, any differences in their bloodwork can be more confidently attributed to the chiropractic care itself — not just the experience of being treated.
The key findings, in plain English
The researchers measured a whole panel of biomarkers — molecules in your blood that tell a story about what's happening inside your body. Here are the highlights:
1. BDNF went up — your brain's growth fertilizer
BDNF (Brain-Derived Neurotrophic Factor) is a protein that helps your brain and nervous system grow, adapt, and repair. Think of it as fertilizer for your nerve cells.
After 12 weeks of chiropractic care, BDNF levels were significantly higher in the adjustment group compared to the sham group. This suggests that regular chiropractic adjustments may actively support the health and adaptability of your nervous system — a concept known as neuroplasticity.
2. TNF-alpha went down — less harmful inflammation
TNF-alpha (Tumor Necrosis Factor-Alpha) is one of the body's primary inflammatory signals. Chronically elevated TNF-alpha is linked to arthritis, heart disease, autoimmune disorders, and chronic pain.
TNF-alpha levels were significantly lower in the chiropractic group at both the 12-week and 16-week marks. This means not only did inflammation decrease during care — it stayed lower even a month after the adjustments stopped. This is one of the most compelling findings of the study.
3. IL-6 went up — but in a good way
IL-6 (Interleukin-6) plays dual roles: when produced during infection it drives inflammation, but when released by muscles during physical activity, it promotes healing and tissue repair.
IL-6 levels were higher in the chiropractic group at 12 weeks but returned to normal by 16 weeks (after adjustments stopped). The researchers believe this was the "muscle" variety — the repeated spinal adjustments were acting like targeted exercise for the deep muscles along the spine, triggering a repair and regeneration response. This interpretation is supported by the fact that CRP (another inflammation marker) did not increase.
4. Cortisol patterns shifted — better stress regulation
Cortisol is your body's primary stress hormone. It's essential in small doses, but chronically elevated cortisol wreaks havoc on your immune system, sleep, digestion, and mood.
A complex but encouraging picture emerged. Salivary cortisol was slightly elevated during the 12 weeks of active care, which makes sense as the body responded to the adjustments. However, by the 16-week follow-up, blood cortisol levels were significantly lower in the chiropractic group. This suggests the body's overall stress load was reduced after the course of care. Hair cortisol (a measure of long-term stress) also trended downward, though this didn't reach statistical significance.
5. IFN-gamma rose in the sham group — the untreated group got worse
IFN-gamma (Interferon-Gamma) is a cytokine involved in activating the immune response to damaged or infected cells. Higher levels can indicate ongoing tissue damage.
At 16 weeks, IFN-gamma was significantly higher in the sham group — not because the chiropractic group improved, but because the group that didn't receive real adjustments appeared to get progressively more inflamed over time. This suggests that leaving spinal dysfunction untreated may allow a slow buildup of systemic inflammation.
6. Immune cells responded within the chiropractic group
CD4 (T-helper cells), CD8 (cytotoxic T cells), and CD19 (B-lymphocytes) are key players in your adaptive immune system.
Several immune cell markers showed significant increases within the chiropractic group over 12 weeks. While the between-group differences didn't reach statistical significance for these markers, the within-group changes suggest the immune system was becoming more active and responsive with regular chiropractic care.
What does this all mean?
Zooming out, this study provides early evidence that 12 weeks of regular chiropractic adjustments can:
- Support brain and nervous system health by increasing BDNF (neuroplasticity)
- Reduce harmful chronic inflammation by lowering TNF-alpha
- Stimulate healthy tissue repair through the "exercise-like" release of IL-6 in spinal muscles
- Improve the body's long-term stress regulation as shown by cortisol patterns
- Prevent the worsening of systemic inflammation that appears when spinal dysfunction goes untreated
This is significant because it moves the conversation about chiropractic care beyond "it helps my back feel better" into the realm of measurable, systemic physiological change. Your spine isn't just a stack of bones — it's the highway for your entire nervous system. When it functions properly, the benefits ripple outward to your immune system, your stress response, and your body's ability to heal.
A few important caveats
No single study tells the whole story, and the researchers were transparent about the limitations:
- The sample size was modest (88 completed the 12-week measures), so larger studies are needed to confirm these findings
- Some effect sizes were small — meaning while the changes were statistically significant, they were not dramatic
- The study looked at people with subclinical spinal pain (recurring aches they hadn't sought treatment for), so results may differ for people with more severe conditions
- Future studies should link these biomarker changes to actual clinical outcomes like pain reduction, function, and quality of life
Why this matters for you
Whether you're dealing with chronic pain, recovering from an injury, or simply trying to stay healthy and resilient, this research reinforces something chiropractors have observed clinically for decades: consistent chiropractic care does more than manage symptoms — it helps your body work better from the inside out.
At Restored Chiropractic, we focus on identifying and correcting spinal dysfunction using the Gonstead method — one of the most precise approaches in the profession. If you're curious about how regular adjustments could benefit not just your spine but your overall health, we'd love to talk.
Schedule a free 15-minute discovery call or book your first appointment today.
Reference: Amjad I, Niazi IK, Kumari N, et al. The effects of 12 weeks of chiropractic spinal adjustments on physiological biomarkers in adults: A pragmatic randomized controlled trial. PLoS ONE. 2025;20(12):e0338730. doi:10.1371/journal.pone.0338730