Fasting and Caloric Restriction Show Promise for Oral Health Inflammation
A systematic review finds intermittent fasting and caloric restriction may reduce periodontal inflammation and support oral tissue health.
Summary
A systematic review of 14 studies examined how fasting, caloric restriction, and ketogenic diets affect oral health conditions including periodontal disease, salivary gland dysfunction, and oral cancer. Caloric restriction and intermittent fasting were linked to reduced periodontal inflammation and improved metabolic markers, while alternate-day fasting showed benefits for salivary gland function in animal models. In oral squamous cell carcinoma research, fasting-based interventions enhanced treatment sensitivity and slowed tumor growth experimentally. However, the evidence base is largely preclinical, and clinical trials in humans remain scarce. The authors conclude that while these dietary strategies show biological plausibility for oral health benefits, well-designed human trials are urgently needed before clinical recommendations can be made.
Detailed Summary
Oral diseases like periodontal disease, salivary gland dysfunction, and oral squamous cell carcinoma share a common thread: chronic inflammation and metabolic dysregulation. While dietary interventions such as intermittent fasting and caloric restriction are well-established for their systemic anti-inflammatory effects, their specific impact on oral health has been largely overlooked — until now.
This PROSPERO-registered systematic review, conducted in accordance with PRISMA 2020 guidelines, searched PubMed and Web of Science for studies published through September 2025. Researchers focused on three dietary interventions — fasting, caloric restriction, and ketogenic diet — and their effects on measurable oral health outcomes. Fourteen studies met inclusion criteria, spanning preclinical in vitro and in vivo models alongside a limited number of clinical trials.
The results paint an encouraging but preliminary picture. Caloric restriction and intermittent fasting were generally associated with improvements in periodontal inflammation and related metabolic parameters. Notably, neither approach appeared to significantly alter oral microbiota composition. Alternate-day fasting demonstrated beneficial effects on salivary gland function and inflammatory markers, though this was primarily in preclinical models. For oral squamous cell carcinoma, fasting-related interventions showed potential in enhancing treatment sensitivity and reducing experimental tumor growth, but clinical evidence remains extremely limited.
The ketogenic diet's role was the least supported, with feasibility data drawn mainly from small pilot studies constrained by methodological limitations. The authors highlight that current evidence is both sparse and heterogeneous, making it premature to integrate these dietary approaches into standard oral health care protocols.
For clinicians and health-conscious patients alike, this review signals an emerging and underexplored intersection between dietary patterns and oral health. The mechanistic rationale is sound — fasting modulates inflammation, autophagy, and metabolic signaling pathways relevant to oral tissues. What is now needed are rigorous, adequately powered human clinical trials to translate these promising preclinical signals into actionable clinical guidance.
Key Findings
- Intermittent fasting and caloric restriction reduced periodontal inflammation and improved metabolic markers across multiple studies.
- Alternate-day fasting improved salivary gland function and inflammatory responses in preclinical models.
- Fasting-based interventions enhanced treatment sensitivity and reduced tumor growth in oral cancer experimental studies.
- Neither fasting nor caloric restriction significantly altered oral microbiota composition.
- Ketogenic diet evidence for oral health is very limited, derived mainly from small, methodologically weak pilot studies.
Methodology
This PROSPERO-registered systematic review searched PubMed and Web of Science for studies published through September 2025 using MeSH terms combining dietary interventions with oral health conditions. Fourteen studies were included, encompassing preclinical in vitro and in vivo experiments as well as a limited number of clinical trials. The review was conducted in accordance with PRISMA 2020 reporting guidelines.
Study Limitations
The evidence base consists predominantly of preclinical in vitro and in vivo studies, with very few human clinical trials, limiting direct clinical applicability. Study heterogeneity across designs, populations, and outcome measures makes cross-study comparisons difficult. Additionally, this summary is based on the abstract only, as the full text was not accessible.
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