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Food selection based on high total antioxidant capacity improves endothelial function in a low cardiovascular risk population.
Franzini, L, Ardigò, D, Valtueña, S, Pellegrini, N, Del Rio, D, Bianchi, MA, Scazzina, F, Piatti, PM, Brighenti, F, Zavaroni, I
Nutrition, metabolism, and cardiovascular diseases : NMCD. 2012;(1):50-7
Abstract
BACKGROUND AND AIMS Oxidative stress has been advocated as a major cause for cardiovascular disease (CVD), and low plasma antioxidant concentrations are associated with endothelial dysfunction, the first step towards atherosclerosis. However, although the antioxidant content in fruits and vegetables may explain at least in part their protective effect against CVD, supplementation with antioxidant vitamins fails to improve endothelial function and reduce CVD risk. The aim of this study was to investigate the impact of a diet rich in antioxidants on endothelial function measured by flow-mediated dilatation (FMD) in volunteers at low cardiovascular risk. METHODS AND RESULTS In a crossover trial, 24 subjects (13 women, mean age 61 ± 3 years), received, in a randomised order, a 14-day high (HT) and a 14-day low (LT) antioxidant diets, with a 2-week wash-out (WO) in between. Both diets were comparable in daily portions of fruits and vegetables, and in alcohol, fibre and macronutrient intake, but differed in their total antioxidant capacity. Before and after each diet, anthropometrics, blood pressure, fasting plasma glucose, lipid profile, hepatic enzymes, circulating antioxidant concentrations, high sensitivity C-reactive protein (hs-CRP) and FMD were assessed. FMD increased significantly during the HT diet compared to the LT (p < 0.000). FMD values were 2.3% higher after HT compared with LT (p < 0.001) after adjustment for age, gender and diet order. α-tocopherol increased significantly (p < 0.05) and hs-CRP and of γ-glutamyltranspeptidase decreased significantly (p < 0.05 and p < 0.01, respectively) during the HT diet, compared with the LT diet. CONCLUSIONS A short-term HT diet improves endothelial function in volunteers at low cardiovascular risk, which may further reduce their risk of CVD.
2.
Total antioxidant capacity of the diet is associated with lower risk of ischemic stroke in a large Italian cohort.
Del Rio, D, Agnoli, C, Pellegrini, N, Krogh, V, Brighenti, F, Mazzeo, T, Masala, G, Bendinelli, B, Berrino, F, Sieri, S, et al
The Journal of nutrition. 2011;(1):118-23
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Abstract
Experimental studies suggest that oxidative stress and systemic inflammation are involved in the pathogenesis of ischemic stroke. Consuming a diet with a high total antioxidant capacity (TAC) has been related to reduced inflammation and increased circulating antioxidants in cross-sectional and randomized intervention studies. This study investigates the relation between dietary TAC and risk of ischemic and hemorrhagic stroke in 41,620 men and women not previously diagnosed with stroke or myocardial infarction, representing the Italian segment of the European Prospective Investigation into Cancer and Nutrition. Controlling for potential confounders, a diet rich in TAC was associated with a reduction in HR for all types of stroke, but this association was only marginally significant (P-trend = 0.054). When only ischemic stroke cases were considered, data suggest a stronger inverse association with dietary TAC, with HR = 0.41 (95% CI = 0.23-0.74). Regarding single antioxidants, data from subanalyses on stroke types suggest that vitamin C is significantly associated with a decreased risk of ischemic stroke [HR = 0.58 (95% CI = 0.34-0.99)], whereas vitamin E was associated with increased HR of hemorrhagic stroke in the highest tertile of intake [HR = 2.94 (95% CI = 1.13-7.62)]. In conclusion, our findings suggest that antioxidants may play a role in reducing the risk of cerebral infarction but not hemorrhagic stroke. However, a high intake of vitamin E could be positively associated to the risk of brain hemorrhagic events; therefore, more focused investigations about this observation are needed.