Fruit juice drinks prevent endogenous antioxidant response to high-fat meal ingestion.

High-fat meals (HFM) induce metabolic stress, leading to the activation of protective mechanisms, including inflammation and endogenous antioxidant defences. In the present study, we investigated the effects of antioxidant-rich fruit juice drinks on the endogenous antioxidant response induced by HFM. In a double-blind, cross-over design (10 d washout), fourteen overweight volunteers were randomly assigned to one of the following interventions: HFM+500 ml placebo beverage (HFM-PB, free from fruit); HFM+500 ml antioxidant beverage 1 (HFM-AB1; apple, grape, blueberry and pomegranate juices and grape skin, grape seed and green tea extracts); HFM+500 ml antioxidant beverage 2 (HFM-AB2; pineapple, black currant and plum juices). HFM-PB consumption increased the plasma levels of thiols (SH) (4 h, P< 0·001) and uric acid (UA) (2 h, P< 0·01) and total radical-trapping antioxidant parameter (TRAP) (4 h, P< 0·01). Following the consumption of drinks, UA production was significantly reduced with respect to placebo beverage consumption 8 h after HFM-AB2 consumption (P< 0·05). SH levels were reduced 0·5 (P< 0·05), 1 (P< 0·05) and 2 h (P< 0·01) after HFM-AB1 consumption and 2, 4 and 8 h (P< 0·05) after HFM-AB2 consumption. Plasma TRAP (2 h, P< 0·001) and urinary ferric reducing antioxidant power (0-8 h, P< 0·01) were increased by HFM-AB1 consumption, the drink with the highest in vitro antioxidant capacity, but not by HFM-AB2 consumption. In urine, UA levels were significantly increased from basal levels after the consumption of HFM-PB and HFM-AB2. However, neither of the beverages increased the urinary excretion of UA with respect to the placebo beverage. In conclusion, the increase in UA and SH levels induced by HFM as part of an endogenous antioxidant response to postprandial stress can be prevented by the concomitant ingestion of antioxidant-rich fruit juice drinks.

Antioxidant and inflammatory response following high-fat meal consumption in overweight subjects.

PURPOSE: Postprandial metabolic stress as a consequence of ingestion of high-energy meals is recognized as an important risk factor for cardiovascular disease. The objective of this study was to evaluate the inflammatory and antioxidant response of the body to the acute ingestion of a high-fat meal (HFM). METHODS: Fifteen healthy overweight subjects were recruited for the study. After HFM consumption, plasma glucose, insulin, uric acid (UA), triglycerides (TG), total cholesterol (TC), thiols (SH), inflammatory cytokines (IL-6 and TNF-α) and dietary antioxidants were measured at 0, 0, 5, 1, 2, 4, 6 and 8 h points from ingestion. RESULTS: The ingestion of HFM induced significant increases in both TG and TC, with peaks at 4 h (p < 0.001) and 8 h (p < 0.01), respectively. IL-6 and TNF-α significantly increased postprandially, reaching maximum concentrations 8 h after meal consumption (p < 0.001). Whereas plasma concentrations of vitamins and carotenoids were not changed by HFM, SH and UA increased, peaking 2-4 h postingestion (p < 0.001 and 0.01, respectively). Increments of SH and UA were positively correlated with AUC for TG (Pearson coefficient 0.888, p < 0.001 and 0.923, p < 0.001, respectively). CONCLUSIONS: Present results indicate that as a consequence of an excess of dietary fat, the body responds through an inflammatory reaction, which is accompanied by an increment of endogenous antioxidant defenses, mediated by UA and SH, but not by vitamins C and E and carotenoids. Although further studies are needed, results of the current investigation represent novel findings on endogenous strategies of redox defense from fat overloads.