A pilot, randomized controlled trial to examine the health outcomes of raisin consumption in patients with diabetes.

OBJECTIVES: Dried fruits, like their fresh homologues, contain relatively high concentrations of antioxidants. The aim of this study was to determine the health outcomes of raisin consumption on patients with diabetes. METHODS: We examined the effects of dried grapes (Vitis vinifera) cultivated in Greece, namely Corinthian Raisins (CR) on blood pressure, fasting glucose, glucated hemoglobin (HbA1c), lipid peroxidation, high-sensitivity C-reactive protein, antioxidant status, and cytokines in patients with type 2 diabetes mellitus (T2DM). Forty-eight well-controlled patients with T2DM from the diabetes outpatient clinic of our hospital were recruited to a two-armed, randomized, controlled, 24-wk prospective intervention trial in order to examine the health outcomes of CR consumption. All participants were reported to consume less fruits and vegetables than the recommended amount of five servings daily. Participants in the intervention were instructed to consume CR equal to two fruit servings (36 g/d), replacing snacks with similar energy density twice during the day. Anthropometric and blood pressure measurements, assessment of dietary intake, and fasting blood draws were conducted at baseline and at week 24. Also, phenolic compounds present in CR were analyzed in plasma of the patients. t Test for parametric data and Mann-Whitney test or Wilcoxon test for non-parametric data were performed. Significance was set at P < 0.05. RESULTS: Body weight, glycemic control, and lipid profile were not affected in either arm. Patients in the CR arm reduced their diastolic blood pressure and increased their total antioxidant potential significantly compared with baseline. The differences between the two groups at week 24 were significant. No change in high-sensitivity C-reactive protein was observed. A significant difference in plasma circulating p-hydroxybenzoic acid was observed between groups at the end of the trial. CONCLUSIONS: Our study shows that naturally CR may improve health features in patients with well-controlled T2DM.

Anti-inflammatory effect of elemental diets with different fat composition in experimental colitis.

The aim of the present study was to evaluate the effectiveness of two isoenergetic elemental formulae with different fat content in the rat model of trinitrobenzene sulphonic acid (TNBS) colitis that mimics human inflammatory bowel disease. A total of forty-five male Wistar rats were assigned to five groups: (1) control group; (2) TNBS-induced colitis group; (3) TNBS-induced colitis group fed a long-chain TAG (LCT)-rich diet; (4) TNBS-induced colitis group fed a medium-chain TAG (MCT)-rich diet; (5) TNBS-induced colitis group fed a baseline diet and administered infliximab. Nutritional management lasted 12 d before and 4 d after rectal administration of TNBS. Subsequently, the rats were killed, and colonic tissue samples were collected for the assessment of histology, inflammation and oxidative stress. The MCT-rich diet decreased IL-6, IL-8 and intercellular adhesion molecule-1 (ICAM-1) levels and glutathione S-transferase (GST) activity, while the LCT-rich diet reduced only ICAM-1 levels and GST activity (P<0.05). Neither elemental formula affected IL-10 levels. Infliximab reduced IL-8 and ICAM-1 levels and GST activity and increased IL-10 levels (P<0.05). No significant differences were detected in oxidative stress. Histological damage scores differed significantly only between the control and the TNBS-induced colitis group. A MCT-rich formula seems to exert stronger anti-inflammatory effects than a LCT-rich formula in TNBS colitis.

Absorption and bioavailability of antioxidant phytochemicals and increase of serum oxidation resistance in healthy subjects following supplementation with raisins.

The aim of this study was to examine the postprandial impact of raisin supplementation in serum resistance to oxidation of healthy subjects, to quantify the bioavailable phenolic compounds and oleanolic acid. The content of phytochemicals in raisins was determined by GC-MS. Fifteen healthy volunteers who consumed 144 g of raisins were subjected to blood collection at time 0 and 1, 2, 3 and 4 h after consumption. Blood samples were used for the quantification of (a) serum oxidizability (b) plasma total polyphenol content and (c) phenolic compounds and oleanolic acid by applying GC-MS analysis. A total of 25 phytochemicals were identified and quantified in raisins, while the triterpenoid oleanolic acid was present at the highest concentration. The peak of plasma total phenolics and serum oxidation resistance appeared 1 h after raisin supplementation (p < 0.05) and correlated strongly with each other. Seventeen phytochemicals (16 phenolics and oleanolic acid) were clearly identified and quantified in volunteers' plasma. Each compound followed different kinetics, however 13 out of 17 peaked in plasma also 1 h after supplementation. The results indicate that raisins influence antioxidant potential in vivo, while the contained phytochemicals are bioavailable.

Bioavailability of the phenolic compounds of the fruits (drupes) of Olea europaea (olives): impact on plasma antioxidant status in humans.

To examine the bioavailability of olive polyphenols and to correlate it with their antioxidant efficacy, plasma and urine from healthy volunteers who had consumed 20 olives were subjected to (a) GC-MS analysis for individual phenolics, (b) estimation of plasma total polyphenol content and (c) estimation of plasma total antioxidant potential. Olive polyphenols were absorbed and metabolized within the body, occurring in plasma mainly in the conjugated form with glucuronic acid and reaching C(max) in 1-2h. Excretion rates were maximum at 0-4h. Tyrosol and hydroxytyrosol increased in plasma after intervention. Total antioxidant potential increased (p<0.05). The results indicate that olive polyphenols possess good bioavailability, which is in accordance with their antioxidant efficacy.

Dietary antioxidants in preventing atherogenesis.

Several naturally occurring constituents have received considerable attention because of their potential antioxidant activity. Consuming a diet rich in natural antioxidants has been associated with prevention from and/or treatment of atherosclerosis. Bioactive components of food, which are of special interest, include the Vitamins E and C, polyphenols, carotenoids-mainly lycopene and beta-carotene, and coenzyme Q10, featured by antioxidant properties. Antioxidant therapy is supposed to be effective in the early stages of atherosclerosis by preventing LDL oxidation and the oxidative lesion of endothelium. This review focuses on the effect of dietary antioxidants pertained to LDL oxidation and to the vascular endothelial dysfunction. Now that the human genome has been completely sequenced, genetic factors involved in oxidation may open new horizons to identify persons at risk for cardiovascular disease, allowing effective dietary intervention strategies to recover normal homeostasis and to prevent diet-related implications. On this basis, current studies on the action of selected antioxidant nutraceuticals on the activity of transcription factors, such as final targets in the signal transduction cascade and gene regulation, may emerge into new treatment concepts.

Dietary intake and biochemical risk factors for cardiovascular disease in two rural regions of Crete.

The aim of the present study was to identify any possible protective effects of wild greens on certain biochemical cardiovascular disease (CVD) risk factors in elderly women leaving in rural Crete. For the needs of the study a region with high consumption of wild greens (Avdou) and a region with low consumption (Anogia) were identified and a representative population from each area was recruited (n= 37 and n=35 respectively). Serum lipids and fibrinogen levels, total antioxidant capacity (TAC), soluble intercellular adhesion molucule-1 (sVCAM-1), soluble vascular adhesion molucule-1 (s-ICAM-1) and haematological factors were measured in both regions during winter and summer time when wild-green plants consumption is high and low, respectively. Regarding classic lipid risk factors for arteriosclerosis no significant different between the two regions were detected. TAC was found higher in Avdou compared to Anogia during winter screening, but null in both regions during summer. Fibrinogen was found higher in Avdou compared to Anogia while no differences between the two regions were detected for sVCAM-1 and s-ICAM-1 in both screenings. The significantly higher TAC and fibrinogen values detected in Avdou could be attributed to the higher wild green consumption in that region since recent data indicated that their content in vitamin C and E as well as flavonoids is particularly high.