The relationship between dietary patterns and neuroinflammation

Dietary patterns are now recognized as key modulators of immunometabolic balance, exerting significant effects on the central nervous system (CNS) by regulating immune responses and inflammatory stress. The quality, composition, and timing of nutrient intake shape immune responses, influence glial activity, and alter the vulnerability of the CNS to inflammatory processes. Persistent neuroinflammation, driven by microglial activation, chronic release of pro-inflammatory mediators, and recruitment of peripheral immune cells, is increasingly recognized as a common mechanism underlying a wide range of neurological and psychiatric disorders, from Alzheimer's disease to major depression, reducing the patients' quality of life. The transition from evolutionarily adapted diets, rich in fiber, micronutrients, and unprocessed foods, to Western dietary patterns characterized by excess saturated fats, refined sugars, and ultra-processed products has significantly disrupted systemic and neuroimmune homeostasis. These nutritional changes contribute to a pro-inflammatory brain environment both directly, through the immunomodulatory effects of dietary components and metabolites, and indirectly, through increased intestinal permeability, dysbiosis, and activation of peripheral inflammatory cascades. Conversely, nutritional strategies such as plant-based, low-fat, low-carbohydrate, Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), and time-restricted diets appear to counteract these detrimental effects. Preclinical and early clinical evidence suggests that these approaches reduce microgliosis, inhibit inflammasome signaling, lower systemic inflammation, and reshape the gut microbiota to promote anti-inflammatory metabolites and better gut-brain communication. Although large-scale clinical validation is still needed, shifting dietary patterns from pro-inflammatory to neuroprotective profiles offers a feasible and promising approach to reduce neuroinflammation and support brain health.