Department of Nutrition and Dietetics, Idaho State University, Pocatello, ID 83209, USA.
Department of Biomedical and Pharmaceutical Sciences, Idaho State University, Pocatello, ID 83209, USA.
Int J Environ Res Public Health. 2023 Aug 2;20(15):6502. doi: 10.3390/ijerph20156502.
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 ( = 32) consumed either a grape or placebo drink with a high-fat meal in the morning or evening. Urine was collected for measurements of biomarkers of oxidative stress and grape metabolites at baseline and post-meal at hour 1 and hours 1-6. F-2 isoprostane levels showed main effects of time period (baseline < hour 1 < hours 1-6, < 0.0001), time (a.m. > p.m., = 0.008) and treatment (placebo > grape, = 0.05). Total F2-isoprostane excretion expressed as % baseline was higher in the a.m. vs. p.m. ( = 0.004) and in the a.m. placebo vs. all other groups ( < 0.05). Tartaric acid and resveratrol excretion levels were higher in the grape vs. placebo group ( < 0.05) but were not correlated with F-2 isoprostane levels. The findings support a protective effect of grape consumption against morning sensitivity to oxidative stress.
葡萄的摄入作用于免疫系统，产生抗氧化和抗炎作用。由于免疫活性具有昼夜节律性，其峰值出现在清醒时间，因此葡萄摄入的时间可能会影响其抗氧化作用的大小。本研究采用 2×2 析因随机对照设计，健康男性和女性（n=32）分别在早上或晚上摄入葡萄或安慰剂饮料和高脂肪餐。在基线和餐后 1 小时及 1-6 小时收集尿液，以测量氧化应激和葡萄代谢物的生物标志物。F-2 异前列腺素水平显示出时间（基线<1 小时<1-6 小时，<0.0001）、时间（上午>下午，=0.008）和处理（安慰剂>葡萄，=0.05）的主要影响。以基线的%表示的总 F2-异前列腺素排泄在上午高于下午（=0.004），且上午安慰剂高于其他所有组（<0.05）。葡萄组的酒石酸和白藜芦醇排泄水平高于安慰剂组（<0.05），但与 F-2 异前列腺素水平无相关性。这些发现支持葡萄摄入对早晨氧化应激敏感性的保护作用。
