Eunyoung Park

Protective activity of processed tomato products on postprandial oxidation and inflammation: A clinical trial in healthy weight men and women

SCOPE This study was designed to evaluate the ability of tomato rich in lycopene to modify postprandial oxidative stress, inflammation, and endothelial function in healthy weight individuals. METHODS AND RESULTS Twelve women and 13 men (mean age = 27 ± 8 years; mean body mass index= 22 ± 2) consumed high-fat meals known to induce postprandial oxidative stress on two separate occasions containing either processed tomato product or non-tomato alternative. Blood samples were collected at 0, 30, 60, 90, 120 min, then hourly until 360 min. Flow-mediated dilation (FMD) was performed at 0 and 210 min. Endpoints included changes in glucose, insulin, lipids, oxidized low-density lipoprotein (OxLDL), inflammatory cytokines, and FMD. Both meals induced increases in plasma glucose, insulin, and lipid concentrations (p < 0.05). A trend for higher triglycerides at >240 min was observed after the tomato meal (p = 0.006). Tomato significantly attenuated high-fat meal-induced LDL oxidation (p < 0.05) and rise in interleukin-6 (p < 0.0001), a proinflammatory cytokine and inflammation marker. CONCLUSION The data indicate that consuming tomato products with a meal attenuates postprandial lipemia-induced oxidative stress and associated inflammatory response. The relevance of OxLDL and inflammation to vascular injury suggests a potentially important protective role of tomato in reducing cardiovascular disease risk. ClinicalTrials.gov Registration number - NCT00966550.

A pilot study to investigate bioavailability of strawberry anthocyanins and characterize postprandial plasma polyphenols absorption patterns by Q-TOF LC/MS in humans

BACKGROUND: Information on absorption and metabolism of strawberry polyphenols is limited. OBJECTIVE: The aim of this study was to characterize and quantify plasma polyphenols/anthocyanins across 4 doses of strawberry using Q-TOF LC/MS and LC-MS/MS analysis. METHOD: Plasma was collected from 5 subjects (n = 5) every 30–60 min for 6 h after consuming beverages containing 0, 10, 20 or 40 g freeze-dried strawberry powder with a meal. RESULTS: Q-TOF LC/MS and LC-MS/MS analysis of plasma revealed 33 compounds; 7 not reported previously. Pelargonidin-O-glucuronide (PG) was the most abundant metabolite. Maximum concentrations (Cmax) of PG were achieved at 148 ± 31 min and were significantly different among beverages containing 0, 10, 20, 40 g strawberry powder: 0, 93.4 ± 21.9, 166.5 ± 16.2 and 226.7 ± 36.7 nmol/L, respectively (P < 0.05). Area under the concentration curve (AUC) also increased with dose (P < 0.05); however, Cmax and AUC of PG was reduced as a percent of pelargonidin-3-O-glucoside (P3G) delivered in the strawberry beverages (P < 0.05). CONCLUSION: Use of both Q-TOF LC/MS and LC-MS/MS allowed for detection of compounds in plasma not previously reported, which may be a useful approach for characterizing postprandial plasma metabolites of lesser known plant foods. Additionally, higher concentrations of key strawberry compounds/metabolites are achieved with eating more strawberry; however, saturation of absorptive capacity of pelargonidin-based anthocyanins was suggested.

Pharmacokinetic Characterization and Bioavailability of Strawberry Anthocyanins Relative to Meal Intake

Plasma strawberry anthocyanins were characterized in overweight (BMI: 26 ± 2 kg/m(2)) adults (n = 14) on the basis of meal timing. At each visit, subjects ingested three study drinks: two control and one strawberry drink. A strawberry drink was given at either 2 h before the breakfast meal (BM), with the meal (WM), or 2 h after the meal (AM), and control drinks were given at the alternative time points. Plasma anthocyanins and their metabolic conjugates were assessed hourly for 10 h using a triple-quadrupole liquid chromatography mass spectrometer. Maximum concentrations (Cmax), area under the curve (AUC), and bioavailability of pelargonidin-based anthocyanins determined from the main conjugated metabolite (pelargonidin glucuronide) were greater when a strawberry drink was consumed 2 h before the meal (BM) compared to consumption WM or AM (p < 0.05). Our results indicate that the timing of strawberry consumption relative to a meal impacts anthocyanin pharmacokinetic variables.

Effects of grape seed extract beverage on blood pressure and metabolic indices in individuals with pre-hypertension: a randomised, double-blinded, two-arm, parallel, placebo-controlled trial

The aim of the present study was to test grape seed extract (GSE) as a functional ingredient to lower blood pressure (BP) in individuals with pre-hypertension. A single-centre, randomised, two-arm, double-blinded, placebo-controlled, 12-week, parallel study was conducted in middle-aged adults with pre-hypertension. A total of thirty-six subjects were randomised (1:1) to Placebo (n 18) or GSE (n 18) groups; twenty-nine of them completed all the protocol-specified procedures (Placebo, n 17; GSE, n 12). Subjects consumed a juice (167 kJ (40 kcal)) containing 0 mg (Placebo) or 300 mg/d GSE (150 mg) twice daily for 6 weeks preceded by a 2-week Placebo run-in and followed by 4-week no-beverage follow-up. Compliance was monitored. BP was measured at screening, 0, 6 and 10 weeks of intervention and blood samples were collected at 0, 3, 6 and 10 weeks of intervention. GSE significantly reduced systolic BP (SBP) by 5·6 % (P=0·012) and diastolic BP (DBP) by 4·7 % (P=0·049) after 6 weeks of intervention period, which was significantly different (SBP; P=0·03) or tended to be different (DBP; P=0·08) from Placebo. BP returned to baseline after the 4-week discontinuation period of GSE beverage. Subjects with higher initial BP experienced greater BP reduction; nearly double the effect size. Fasting insulin and insulin sensitivity tended to improve after 6 weeks of GSE beverage supplementation (P=0·09 and 0·07, respectively); no significant changes were observed with fasting plasma lipids, glucose, oxidised LDL, flow-mediated dilation or vascular adhesion molecules. Total plasma phenolic acid concentrations were 1·6 times higher after 6 weeks of GSE v. Placebo. GSE was found to be safe and to improve BP in people with pre-hypertension, supporting the use of GSE as a functional ingredient in a low-energy beverage for BP control.

Diet adherence dynamics and physiological responses to a tomato product whole-food intervention in African-American men.

Tomatoes may have beneficial effects on prostate health. Efficacy trials would require long-term adherence to high levels of tomato product (TP) consumption. Therefore, factors that affect adherence in men most at risk and whether increased consumption of TP negatively affects diet and health are important concerns. Cancer-free African–American (AA) men (n 36) with mean serum prostate-specific antigen of 7.4 SD 5.6) ng/ml were randomised to consume one serving of TP/d or a control diet for 3 months. Mean intervention group lycopene intake rose to 464%, with negligible control group increase. Plasma lycopene levels rose by 53 and 40% in the intervention group in months 1 and 3, respectively (P < 0.0001), with no control group change. The intervention group’s barriers to adherence score was inversely associated with both dietary (r -0.49, P = 0.02) and plasma lycopene concentration (r -0.37, P = 0.02). Their TP disadvantage score negatively correlated with the 3-month plasma lycopene concentrations (r -0.37, P = 0.008) and their weekly incentives and impediments were remarkably stable, ‘concern for prostate health’ being the most consistent over time. ‘Liking tomatoes’ and ‘study participation’ decreased in citation frequency at weeks 6 and 9, respectively. No major shifts occurred in dietary cholesterol or saturated fat, with no adverse effects on gastrointestinal complaints, serum total cholesterol, body weight or blood pressure. Lower socio-economic status AA men at higher prostate cancer risk can successfully achieve a whole food intervention goal with a corresponding rise in plasma lycopene concentrations, with no adverse effects on self-selected diet quality or health parameters.

Short-term effects of chewing gum on satiety and afternoon snack intake in healthy weight and obese women.

Afternoon snacking contributes significantly to total energy intake. Strategies to enhance the satiety value of lunch and reduce afternoon snacking are of interest for body weight management. To assess whether between-meal gum chewing would enhance the satiety response to a fixed lunch meal; and assess the role of cholecystokinin (CCK) as a potential mediator of the response in non-obese healthy weight and obese women. Fifty unrestrained obese (n=25) and non-obese healthy weight (n=25) women participated in a two-arm cross-over study assessing multiple (15min per hour×3h) gum chewing (GUM) occurrences or no gum (Control) on subjective ratings of satiety, subsequent sweet and salty snack intake, CCK and general metabolic responses. GUM compared to Control resulted in significant suppression of hunger, desire to eat and prospective consumption (p<0.05). Total snack energy intake was reduced ~9.3% by GUM, but not significantly different from Control (p=0.08). However, overall carbohydrate intake was reduced by GUM (p=0.03). This was consistent with a reduction in snacks characterized as high carbohydrate, low fat (p=0.02). BMI specific effects indicated GUM reduced pretzel intake in obese women (p=0.05) and Oreo cookie intake in healthy weight women (p=0.03) 3h after lunch. Metabolic responses and CCK did not differ between experimental conditions. Chewing gum intermittently post-lunch enhances perceptions of satiety and may have important implications in reducing afternoon high carbohydrate-snack intake.