Nutritional Intervention for Sjögren Disease: A Systematic Review

Background/Objectives: The impact of nutritional interventions on Sjögren disease (SD) remains uncertain, and no standardized guidelines currently exist for managing its sicca symptoms. This systematic review evaluated the effects of dietary interventions on the symptoms of dry mouth and dry eyes in individuals with SD. Methods: Electronic searches were performed in four databases, supplemented by manual searches and searches of the gray literature. Both human and animal studies were included. The methodological quality of the selected studies was appraised, and the data were analyzed descriptively. Results: A total of nineteen studies (ten in humans and nine in animal models) were included. The treatments evaluated were dietary supplements, vitamins, medicinal herbs, and specially modified diets. The primary outcomes assessed included unstimulated and stimulated whole salivary flow rates, salivary-gland inflammation, and ocular dryness (Schirmer test). In animal models of SD, interventions such as caloric restriction, gluten-free diets, low-fat diets, and supplements (e.g., resveratrol, triptolide, and Lycium barbarum polysaccharide) were associated with increased salivary flow and reduced glandular inflammation. Conversely, diets rich in saturated fats were associated with reduced salivary flow and increased lymphocytic infiltration in salivary glands. Human studies yielded mixed results, with some reporting improvements in salivation following interventions with vitamins, herbal supplements, gluten-free diets, liquid diets, and whole-food, plant-based diets. Conclusions: Although dietary management may alleviate sicca symptoms and improve nutritional status in SD, the current evidence is insufficient to support specific recommendations for the management of oral symptoms.