The methodology of the research includes a comprehensive review of the existing studies and experiments on walnuts and their active ingredients. These ingredients include large amounts of unsaturated fatty acids, peptides, and phenolic compounds known for their anti-inflammatory effects. Various studies covering the effect of these ingredients on the brain health of both rats and humans were analyzed. Specifically, the regulation of microglia activation induced by substances like amyloid β or lipopolysaccharides, the inhibition of peripheral inflammation led by macrophages, and the effects on oxidative stress and gut microbes were scrutinized.

In the discussion of results, the studies presented compelling evidence of the beneficial effects of walnuts and their components on neuroinflammation and potential ways to counteract neurodegeneration. There seems to be a consensus in the experimental investigations that the walnut’s active ingredients can reduce inflammation and oxidative stress while maintaining gut homeostasis. They also show promise in improving cognitive functions and memory in both rats and humans. However, it was noted that the evidence from human clinical studies is not as abundant or conclusive as the experimental work, although the potential of walnut-based functional foods in mitigating neurodegenerative diseases was recognized.