Chronic inflammatory diseases such as Crohn’s disease represent a major therapeutic challenge, as they involve persistent immune activation, systemic inflammation, and increased long-term risk of cardiovascular complications. While conventional treatments can be effective, they are often associated with side effects or incomplete disease control. This has prompted interest in natural compounds with documented anti-inflammatory activity in humans. One of the most rigorously studied of these is Chios mastic gum, a resin obtained exclusively from Pistacia lentiscus trees grown on the Greek island of Chios. Human clinical and mechanistic studies published in the mid-2000s provide some of the strongest evidence to date for its biological activity.

One of the most frequently cited human trials investigating Chios mastic gum was conducted by Kaliora and colleagues and published in the World Journal of Gastroenterology in 2007. This study focused on patients with active Crohn’s disease, a form of inflammatory bowel disease characterized by elevated systemic inflammation and relapsing intestinal symptoms. In the trial, patients received 2.2 grams per day of authentic Chios mastic gum for four weeks. Importantly, the researchers assessed not only clinical symptoms but also objective inflammatory biomarkers, strengthening the clinical relevance of the findings.

By the end of the intervention, patients showed significant reductions in C-reactive protein (CRP) and interleukin-6 (IL-6), two key markers of systemic inflammation closely linked to disease activity and prognosis in Crohn’s disease. These biochemical improvements were accompanied by measurable clinical improvement in disease activity scores. Notably, the treatment was well tolerated, and no serious side effects were reported. This study is widely regarded as one of the clearest demonstrations that a plant-derived resin can meaningfully reduce inflammation in an active human inflammatory disease (World Journal of Gastroenterology, 2007).

To better understand how these clinical effects might arise, the same research group conducted follow-up mechanistic studies, also published in the World Journal of Gastroenterology (2007) and in Atherosclerosis (2004). These investigations examined the direct effects of Chios mastic gum on human immune and vascular cells in controlled experimental settings. The results showed that mastic gum significantly suppressed tumor necrosis factor-alpha (TNF-α), a master cytokine that drives inflammation in Crohn’s disease and is the primary target of several biologic drugs used clinically.

In addition to its effects on immune signaling, Chios mastic gum was shown to downregulate endothelial adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). These molecules play a crucial role in allowing immune cells to adhere to blood vessel walls and migrate into tissues, a process central not only to intestinal inflammation but also to the early development of atherosclerosis. By reducing VCAM-1 and ICAM-1 expression, mastic gum demonstrated a dual anti-inflammatory and vasculoprotective profile, linking intestinal immune modulation with broader cardiovascular relevance (Atherosclerosis, 2004).

A critical point emphasized repeatedly by the authors is that these effects are not attributable to generic “mastic” products. Chemical analyses revealed that the biological activity was associated with specific triterpenes unique to authentic Chios mastic gum. As a result, the researchers explicitly highlighted geographic origin as a decisive factor, noting that resin from other regions does not share the same phytochemical composition or biological potency. This distinction is especially important in clinical and commercial contexts, where products labeled simply as “mastic” may vary widely in composition and effectiveness.

Taken together, this body of research provides a rare example of convergence between human clinical data and mechanistic evidence for a natural product. The Crohn’s disease trial demonstrates that Chios mastic gum can reduce systemic inflammation and improve clinical outcomes in patients, while mechanistic studies explain these effects through suppression of TNF-α and inhibition of endothelial adhesion pathways. These findings position Chios mastic gum as a scientifically credible anti-inflammatory agent rather than a purely traditional remedy.

In conclusion, human clinical and mechanistic studies published in World Journal of Gastroenterology and Atherosclerosis show that authentic Chios mastic gum exerts significant anti-inflammatory effects in Crohn’s disease and vascular inflammation. By lowering CRP, IL-6, TNF-α, and adhesion molecule expression, it targets core inflammatory pathways relevant to both intestinal and cardiovascular disease (World Journal of Gastroenterology, 2007; Atherosclerosis, 2004). While larger and longer trials are still needed, the existing evidence places Chios mastic gum among the best-documented plant-derived anti-inflammatory interventions tested in humans.