Abstract
Introduction: Type 2 diabetes mellitus (T2DM) and periodontitis are two prevalent chronic conditions that have been implicated in each other in a bidirectional manner, whereby hyperglycemia can predispose to periodontal disease, and periodontal inflammation can lead to hyperglycemia. Both conditions are linked via nutrition, which affects systemic inflammation, oxidative stress, and the host response in the periodontal tissues. Objective: The aim was to review the existing literature on the association between glycemic control, food intake and periodontal status in T2DM adults and to provide insight into the importance of integrated nutritional and periodontal care. Methods: PubMed/MEDLINE, Scopus, and Web of Science were queried for observational studies, interventional trials, systematic reviews, and mechanistic studies related to T2DM and glycated hemoglobin (HbA1c) levels, diet and micronutrient exposures, and periodontal parameters. Results: There is a consistent relationship between poor glycemic control (HbA1c ≥ 7%) and increased periodontal inflammation, pocket depth and attachment loss; severe periodontitis is associated with poorer glycemic control; non-surgical periodontal therapy is associated with a short-term decrease of 0.3-0.4% in HbA1c. Mechanistic factors that are common to both include advanced glycation end product-receptor (AGE–RAGE) axis, oxidative stress, and pro-inflammatory cytokine signaling. Western type diets high in refined carbohydrates are associated with increased periodontal inflammation and poor metabolic profiles while low-glycemic diets with a higher omega-3 fatty acid, fiber and antioxidant vitamin (C, D, E) content are associated with decreased periodontal inflammation and better metabolic profiles., whereas Western-type diets high in refined carbohydrates have the opposite effect. Conclusion: There is a bi-directional relationship between glycemic control, nutrition and periodontal health in T2DM. Nutritional assessment and counselling together with diabetes and periodontal management is a plausible and low risk intervention to reduce morbidity, and there is limited high quality evidence.