1. Introduction
inflammation, cancer and neurodegenerative disorders
DISEASE, INFLAMMATION, OXIDATIVE STRESS, CARDIOVASCULAR DISEASE
Grape consumption acts on the immune system to produce antioxidant and anti-inflammatory effects. Since immune activity demonstrates circadian rhythmicity, with peak activity occurring during waking hours, the timing of grape intake may influence the magnitude of its antioxidant effect. This study followed a 2 × 2 factorial randomized, controlled design wherein healthy men and women (Human and animal immune defense activity usually peaks during the active period in the circadian cycle [Isoprostanes are a group of prostaglandin-like compounds produced by the free-radical-catalyzed peroxidation of arachidonic acid. They are considered reliable and specific biomarkers of oxidative stress and have been widely used in clinical and experimental studies to assess oxidative damage in various tissues and fluids. The importance of isoprostanes as oxidative stress biomarkers lies in their stability, sensitivity, and specificity. Several studies have demonstrated the utility of isoprostanes (e.g., F2-isoprostane) as biomarkers of oxidative stress in various disease states, including cardiovascular disease, cancer and neurodegenerative disorders [Grape and grape-derived products are rich sources of natural compounds with potential anti-inflammatory activity. Grape polyphenols exert anti-inflammatory and antioxidant effects through interactions with molecular targets in immune system pathways [Immune system activity displays a circadian rhythm. Since grape components act on molecular targets regulating inflammation and oxidative defense, synchronizing grape intake to peak immune system activity might amplify the fruit’s antioxidant effects. Thus, grape consumption in the morning, when immune defenses are built, versus in the evening, when immune components are being restored/repaired, could exert more potent anti-inflammatory and antioxidant effects.The present study used a randomized, placebo-controlled research design to test for the circadian influence of grape consumption on oxidative damage. Individuals were challenged with a high-fat meal in the morning and evening with reconstituted grape powder. High-fat meals provoke an inflammatory and oxidative stress response [