Postprandial hyperlipemia is a well-defined risk factor for atherosclerosis. A reasonable contributing mechanism could involve the postprandial increase of plasma lipid hydroperoxides (LPO) affecting the oxidant/antioxidant balance and increasing the susceptibility of LDL to oxidation. Wine has been shown to prevent both these events. The present study was designed to investigate the effect of supplementing a meal with grape seed proanthocyanidins (the main phenolic antioxidant of red wine) on plasma postprandial oxidative stress. In two different sessions, 8 healthy volunteers consumed the same test meal rich in oxidized and oxidizable lipids without (control) or with 300 mg of a proanthocyanidin-rich grape seeds extract (GSE). Lipid hydroperoxide concentration, antioxidant status, and LDL resistance to oxidative modification were measured in postprandial plasma. The content of LPO in chylomicrons was 1.5-fold higher after the control meal than after the GSE-supplemented meal. Plasma LPO increased only after consumption of the control meal. The plasma antioxidant capacity increased in the postprandial phase only following the GSE supplemented meal. LDL isolated 3 h after the control meal tended to be more susceptible to oxidative modification (but the difference did not reach statistical significance). An opposite trend was observed following the GSE supplemented meal. In conclusion, the supplementation of a meal with GSE minimizes the postprandial oxidative stress by decreasing the oxidants and increasing the antioxidant levels in plasma, and, as a consequence, enhancing the resistance to oxidative modification of LDL.

Background: Epidemiologic and intervention studies indicate that both diet as a whole and single dietary components are involved in the risk of atherosclerosis. The resistance of LDL to oxidative modification is an ex vivo indicator of risk, which is modulated by dietary components. Coffee contains phenolic compounds with antioxidant activity. These molecules are found in plasma after the consumption of coffee, and it has been shown that, in vitro, they are able to decrease the susceptibility of LDL to oxidation. Objective: The aim of this study was to evaluate the effect of coffee consumption on the redox status of LDL as modulated by the possible incorporation of phenolic acids into LDL. Design: Ten healthy volunteers, after an overnight fast, drank 200 mL filtered coffee. Blood was drawn before and 30 and 60 min after drinking. Changes in LDL redox status were evaluated by the measure of LDL resistance to oxidative modification and the concentration of LDL(Ҁ), a mildly modified, electronegative LDL subfraction. Chlorogenic and phenolic acids concentration in LDL were measured by electrochemical HPLC. Results: The resistance of LDL to oxidative modification increased significantly after coffee drinking, but the LDL(Ҁ) concentration did not increase. The concentration into LDL of conjugated forms of caffeic, p-coumaric, and ferulic acids increased significantly after coffee drinking. Conclusion: Drinking 200 mL (1 cup) coffee induces an increase in the resistance of LDL to oxidative modification, probably as a result of the incorporation of coffee's phenolic acids into LDL. Clin Nutr 2007;86:604 -9. Am J

Epidemiological studies indicate a J-shaped relationship linking coffee consumption and cardiovascular risk, suggesting that moderate coffee consumption can be beneficial. Platelet aggregation is of critical importance in thrombotic events, and platelets play a major role in the aetiology of several CVD. The aim of this study was to evaluate the effect of coffee drinking on platelet aggregation ex vivo, using caffeine as control. A crossover study was performed on ten healthy subjects. In two different sessions, subjects drank 200 ml coffee, containing 180 mg caffeine, or a capsule of caffeine (180 mg) with 200 ml water. Platelets were separated from plasma at baseline and 30 and 60 min after coffee drinking. Platelet aggregation was induced with three different agonists: collagen, arachidonic acid and ADP. Coffee drinking inhibited collagen (P, 0·05 from baseline at time 30 min) and arachidonic acid (P,0·05 from baseline at time 60 min) induced platelet aggregation. Caffeine intake did not affect platelet aggregation induced by the three agonists. Coffee consumption induced a significant increase of platelet phenolic acids (likely present as glucuronate and sulphate derivatives), caffeic acid, the principal phenolic acid in coffee, raising from 0·3 (SEM 0·1) to 2·4 (SEM 0·6) ng/mg (P, 0·01). Caffeine was not detectable in platelets. Coffee drinking decreases platelet aggregation, and induces a significant increase in phenolic acid platelet concentration. The antiplatelet effect of coffee is independent from caffeine and could be a result of the interaction of coffee phenolic acids with the intracellular signalling network leading to platelet aggregation.

The effect of microwave, boiling and pressure cooking on total antioxidant capacity and total phenolics content of seven vegetables were studied. Total phenolics in raw and cooked vegetables were determined by the Folin–Ciocalteu method, whereas the total antioxidant capacity of vegetables extracts was evaluated using the Crocin method. After boiling, four out of seven vegetables (cauliflower, peas, spinach and Swiss chard) showed a significant decrease in their total phenolic content (P < 0.05). No decrease or a smaller decrease was observed for these four vegetables (P < 0.05) after pressure cooking and/or microwaving than after boiling. The total antioxidant capacity of potato and Swiss chard was not significantly affected by cooking procedures, whereas it decreased for spinach and peas, and it increased for tomato and carrots (P < 0.05). In addition, there was a statistically significant correlation between total phenolic content and total antioxidant capacity in cooked and uncooked vegetables, but the strength of the correlation increased when separating carotenoid‐poor from carotenoid‐rich vegetables. PRACTICAL APPLICATIONS All guidelines for a healthy nutrition include recommendation for increasing the consumption of fruit and vegetables also because of their phenolic compounds content and antioxidant capacity. However, all studies correlating antioxidants consumption and health benefits relate food consumption studies with antioxidant capacity of foods, neglecting to consider the chemical composition changes that may occur during cooking. This study provides data in order to better understand the implication on the total antioxidant capacity of foods due to different cooking approaches.