Is mastic gum safe and effective for preserving kidney function or for use in individuals with chronic kidney disease?

Mastic Gum and Kidney Health

Mastic gum lacks sufficient evidence for kidney protection and should be avoided or used with extreme caution in individuals with chronic kidney disease, as current KDIGO guidelines explicitly recommend limiting herbal remedies that may be harmful in CKD patients.

Guideline-Based Recommendation

The 2024 KDIGO Clinical Practice Guideline for CKD management provides clear direction on herbal supplements in kidney disease 1:

• Practice Point 4.1.3 explicitly states: "Review and limit the use of over-the-counter medicines and dietary or herbal remedies that may be harmful for people with CKD" 1
• People with CKD are more susceptible to nephrotoxic effects of medications and supplements 1
• Thorough medication review should include assessment of all herbal products 1

Evidence Analysis

Potential Nephrotoxicity Concerns

The most relevant finding comes from a 2018 systematic review of Persian medicine that identified mastic gum as a traditional "reformer" (protective agent) against kidney damage, but this designation is problematic 2:

• No clinical evidence exists supporting nephroprotective effects in humans
• The review found only 38% of studied herbs had any scientific evidence for renal effects 2
• Traditional use does not equate to proven safety or efficacy in CKD populations

Safety Data in Healthy Subjects

Limited animal and human studies in healthy individuals show:

• A 13-week rat toxicity study found dose-dependent liver weight increases and decreased body weights at high doses, with a NOAEL of 0.67% in diet 3
• A 2016 human trial in healthy volunteers (n=156) showed no gastrointestinal, liver, or renal adverse events over 8 weeks 4
• However, these studies specifically excluded individuals with kidney disease

Critical Gap in Evidence

There are zero published clinical trials evaluating mastic gum safety or efficacy specifically in patients with CKD or impaired kidney function. The absence of evidence is particularly concerning given:

• Unknown pharmacokinetics in reduced GFR states
• Potential for accumulation of metabolites
• Lack of dose-adjustment guidelines for renal impairment

Clinical Algorithm for Decision-Making

For patients with CKD (eGFR <60 mL/min/1.73m²):

1. Advise against use due to lack of safety data in this population
2. If patient insists on use, document discussion of unknown risks
3. Monitor renal function (eGFR, creatinine) more frequently if used (monthly initially) 1
4. Discontinue immediately if any decline in kidney function occurs

For patients with normal kidney function:

1. May be considered relatively safe based on limited healthy volunteer data 4
2. Still recommend caution given lack of long-term safety data
3. Monitor for any systemic effects (liver function, metabolic parameters)

Important Caveats

• Confusion with gum acacia: Some evidence exists for gum acacia (Acacia senegal) showing potential benefits in CKD through microbiome modulation and butyrate production 5, 6, but this is a completely different substance than mastic gum (Pistacia lentiscus)
• The 2024 ESPEN guideline on hospitalized kidney patients makes no mention of herbal supplements, focusing instead on evidence-based nutritional interventions 7
• Quality and purity of commercial mastic gum products are unregulated and variable

Risk-Benefit Assessment

Given the priority of morbidity, mortality, and quality of life outcomes:

• No demonstrated benefit for kidney function preservation
• Unknown but potential harm in vulnerable CKD population
• Alternative evidence-based therapies exist (SGLT2 inhibitors, RAS inhibitors, GLP-1 RAs) with proven kidney protection 1

The risk-benefit ratio does not favor mastic gum use in CKD patients, and resources should be directed toward proven kidney-protective interventions 1.