Lipophilic Oxygen Radical Absorbance Capacity Research Articles

Dietary total antioxidant capacity and the risk of developing asthenozoospermia: a hospital-based case-control study in China.

Is dietary total antioxidant capacity (DTAC) associated with the odds of developing asthenozoospermia in Chinese men? There is no statistically significant association between DTAC indices and the odds of developing asthenozoospermia. Both diet and oxidative stress may be related to sperm quality; however, few studies have investigated the association between DTAC and sperm quality. This case-control study was conducted from June 2020 to December 2020. Those diagnosed with asthenozoospermia were assigned to the case group, whereas those with normal sperm parameters were assigned to the control group. Data from a total of 553 cases and 586 controls were included in the final analysis. Men who had been referred to the infertility clinic of Shengjing Hospital of China Medical University were enrolled. Dietary intake was assessed using a validated food frequency questionnaire. DTAC was based on ferric-reducing ability of plasma (FRAP), total oxygen radical absorbance capacity (T-ORAC), hydrophilic oxygen radical absorbance capacity (H-ORAC), lipophilic oxygen radical absorbance capacity (L-ORAC), total phenolics (TP), total radical-trapping antioxidant parameter (TRAP), and Trolox equivalent antioxidant capacity (TEAC). Asthenozoospermia was defined according to the criteria published in the fifth edition of the World Health Organization laboratory manual for the examination and processing of human semen. No significant association was observed between the DTAC indices and the odds of asthenozoospermia after multivariable adjustment (T3 vs T1, odds ratio (OR) = 0.99, 95% CI: 0.73-1.33 for FRAP; OR = 1.05, 95% CI: 0.77-1.42 for T-ORAC; OR = 0.88, 95% CI: 0.65-1.18 for H-ORAC; OR = 0.98, 95% CI: 0.71-1.34 for L-ORAC; OR = 1.03, 95% CI: 0.76-1.39 for TP; OR = 1.18, 95% CI: 0.87-1.59 for TRAP; and OR = 1.15, 95% CI: 0.85-1.55 for TEAC). Both additive and multiplicative interaction analyses suggested that smoking might modify the association of T-ORAC with the odds of developing asthenozoospermia (relative excess risk due to interaction = 0.45, 95% CI: 0.07-0.83, attributable proportion due to interaction = 0.46, 95% CI: 0.07-0.84 for additive interaction; P = 0.033 for multiplicative interaction). Recall bias and protopathic bias were inevitable in this retrospective case-control study. The estimation accuracy of the DTAC indices may have also affected the findings. To the best of our knowledge, this is the first study to specifically investigate whether an association exists between DTAC and the odds of developing asthenozoospermia. Although no significant association was found, this study provides novel information pertaining to the fields of nutrition and human reproduction. This work was supported by the JieBangGuaShuai Project of Liaoning Province (2021JH1/10400050), the Shengjing Hospital Clinical Research Project (M0071), and the Outstanding Scientific Fund of Shengjing Hospital (M1150). All authors have no competing interests to disclose. N/A.

Antioxidant-Rich Diet, GSTP1 rs1871042 Polymorphism, and Gastric Cancer Risk in a Hospital-Based Case-Control Study.

BackgroundChronic gastritis along with Helicobacter pylori (H. pylori) infection has been implicated in inflammatory response-related genes linked to the causation of gastric cancer. Glutathione S-transferase Pi (GSTP1) plays a role in regulating oxidative stress and detoxification against carcinogenesis. In this study, we aimed to determine whether an antioxidant-rich diet is associated with gastric cancer risk and identify how this association could be altered by GSTP1 genetic variants.MethodsThis study included 1,245 participants (415 cases and 830 controls) matched for age and sex. The dietary antioxidant capacity was estimated based on the oxygen radical absorbance capacity (ORAC) incorporated with a semiquantitative food frequency questionnaire. Five single nucleotide polymorphisms (SNPs) of GSTP1 (rs1695, rs749174, rs1871042, rs4891, and rs947895) were selected among the exome array genotype data.ResultsHigh dietary ORAC was inversely associated with gastric cancer (hydrophilic ORAC OR T3 vs . T1, 95% CI = 0.57, 0.39–0.82, P = 0.004; lipophilic ORAC = 0.66, 0.45–0.95, P = 0.021; total phenolics = 0.57, 0.39–0.83, P = 0.005). The polymorphism rs1871042 increased the risk of gastric cancer (OR, 95% CI = 1.55, 1.10–2.16, P = 0.01, CT+TT vs. CC). A remarkably reduced risk of gastric cancer was observed among those who had a high dietary ORAC according to rs1871042 polymorphism (hydrophilic ORAC OR T3 vs . T1, 95% CI = 0.36, 0.17–0.78, P for trend = 0.013; lipophilic ORAC = 0.58, 0.37–0.93, P for trend = 0.021; total phenolics = 0.38, 0.17–0.83, P for trend = 0.019).ConclusionsOur findings indicate that dietary ORAC intake may be inversely associated with the risk of gastric cancer altered by genetic variants of GSTP1, providing new intervention strategies for gastric cancer patients.

Antioxidant Capacities of Plant-Derived Foods Commonly Consumed in Japan.

To provide reliable data for high quality epidemiological studies examining the relationship between health and antioxidant intake from daily foods, 107 plant-derived food items (12 rice, bread and noodles, 5 potatoes and starches, 9 pulses, 6 nuts/seeds, 29 vegetables, 22 fruits, 5 mushrooms, 7 algae, and 12 beverages) were selected as commonly consumed foods in Japan based on dietary records, and their antioxidant capacities were evaluated by validated hydrophilic- and lipophilic-oxygen radical absorbance capacity (H-ORAC and L-ORAC) methods. The food items covered more than 60% of total food intake for each category on a weight basis. The H-ORAC and L-ORAC values were widely distributed at 0-210 and 0-30 μmol-Trolox equivalent/g, respectively. The foods possessing potent antioxidant capacities were found in vegetables and fruits as well as other plant-derived foods. In most foods measured, the H-ORAC values were much larger than the L-ORAC values, except for certain kinds of pulses, nuts/seeds, mushrooms, and algae. The ORAC data shown here is sufficient to accurately estimate the antioxidant intake from plant-derived foods in Japan, and should be useful in future epidemiological studies aiming to clarify the biological significance of ORAC values.

The Nutritional and Phytochemical Composition of the Indigenous Australian Pindan Walnut (Terminalia cunninghamii) Kernels.

Nutritional composition of the kernels of two types of Pindan walnut (Terminalia cunninghamii), a native nut consumed traditionally by Australian Indigenous peoples, is reported for the first time. Results showed that Pindan walnut kernels contained high levels of fat, protein and ash, approximately 50, 30 and 5% fresh basis, respectively. The levels of minerals in the kernels were much higher than common walnuts and macadamia nuts, especially those of phosphorus, magnesium and zinc. The high amounts of polyphenols in the kernels provided strong hydrophilic antioxidant capacities, of up to 2004mg Trolox equivalents/100g fresh basis using the hydrophilic oxygen radical absorbance capacity assay. Both free polyphenol content and hydrophilic antioxidant capacities of the kernels were higher than those of macadamia nuts, although the lipophilic oxygen radical absorbance capacity was lower. These preliminary studies indicate high potential for wider use of the Pindan walnut as a novel, nutritious and health-promoting food.

Improvement and Interlaboratory Validation of the Lipophilic Oxygen Radical Absorbance Capacity: Determination of Antioxidant Capacities of Lipophilic Antioxidant Solutions and Food Extracts.

A lipophilic oxygen radical absorbance capacity (L-ORAC) assay is an evaluation of the antioxidant capacity of solutions of lipophilic compounds. The concentrations of fluorescein, radical generator, and Trolox standard solutions were optimized to improve the precision of the assay. An interlaboratory study using two antioxidant solutions and three food extracts as test samples conducted in accordance with harmonized protocol demonstrated satisfactory L-ORAC measurements; the intermediate precision relative standard deviations (RSD(int)) ranged from 7.0 to 16.7%, the reproducibility relative standard deviations (RSD(R)) ranged from 14.8 to 19.4%, and the HorRat values ranged from 1.35 to 1.78.

The Antioxidant and Starch Hydrolase Inhibitory Activity of Ten Spices in an In Vitro Model of Digestion: Bioaccessibility of Anthocyanins and Carotenoids.

The antioxidant and starch hydrolase inhibitory activities of cardamom, cloves, coriander, cumin seeds, curry leaves, fenugreek, mustard seeds, nutmeg, sweet cumin, and star anise extracts were investigated in an in vitro model of digestion mimicking the gastric and duodenal conditions. The total phenolic contents in all spice extracts had statistically significantly (P < 0.05) increased following both gastric and duodenal digestion. This was also in correlation with the antioxidant assays quantifying the water-soluble antioxidant capacity of the extracts. The lipophilic Oxygen Radical Absorbance Capacity assay did not indicate a statistically significant change in the values during any of the digestion phases. Statistically significant (P < 0.05) reductions in the anthocyanin contents were observed during the digestion phases in contrast to the carotenoid contents. With the exception of the cumin seed extract, none of the spice extracts showed statistically significant changes in the initial starch hydrolase enzyme inhibitory values prior to gastric and duodenal digestion. In conclusion, this study was able to prove that the 10 spices were a significant source of total phenolics, antioxidant, and starch hydrolase inhibitory activities.

Spices and Herbs May Improve Cardiovascular Risk Factors

Traditional risk factors for cardiovascular disease (CVD) include high blood low-density lipoprotein (LDL) cholesterol, low high-density lipoprotein (HDL) cholesterol, high blood pressure, smoking, and diabetes. Family history and inflammatory factors also affect CVD risk. Diet therapy for treating and managing patients with CVD and for reducing risk among healthy individuals focuses on consuming a diet containing vegetables and fruits; eating whole-grain breads and cereals; choosing poultry, fish, nuts, legumes, and low-fat dairy foods; and limiting the intake of saturated fat, trans-fat, sweets, sugar-sweetened beverages, and red meats. 1 Because spices and herbs are rich in potentially bioactive compounds, clinical studies have examined their effects on blood insulin, blood lipids, and inflammation. EFFECTS OF A SPICE BLEND ON POSTPRANDIAL INSULIN, TRIGLYCERIDES, AND ANTIOXIDANT CAPACITY We designed a pilot study to determine whether a single, large dose (14 g) of a high-antioxidant spice blend incorporated into a test meal caused postprandial blood changes. 2 Six overweight men aged 30 to 65 years were recruited, baseline blood samples were taken, and the men were randomized to 2 test conditions: a control meal consisting of a dessert biscuit, coconut chicken, and cheese bread, or the same control meal with an added spice blend that included black pepper, cinnamon, cloves, garlic powder, ginger, oregano (Mediterranean), paprika, rosemary, and turmeric. Participants could not be blinded to the test condition because of the relatively large amount of spice blend used. Postprandial blood samples were taken immediately after the meal and every 30 minutes thereafter until 8 samples were collected. Blood lipids, glucose, and insulin were measured. The plasma was analyzed for hydrophilic, lipophilic, and total oxygen radical absorbance capacity (ORAC) to provide information about its antioxidant potential. A higher total antioxidant capacity may reflect reduced oxidative stress, which is an underlying cause of many chronic diseases. 3 Addition of spices and herbs to the test meal significantly decreased postprandial insulin area under the curve by 21% (P = .004) and triglycerides area under the curve by 31% (P = .048), as shown in the Figure. Hydrophilic ORAC levels were 13% higher (P = .02) following the spice test meal than following the control meal, whereas lipophilic and total ORAC levels did not differ between the meals. Total blood cholesterol, HDL cholesterol, and glucose levels were not affected by meal condition. These findings suggest that a blend of spices and herbs may help improve levels of postprandial insulin and triglyceride concentrations after a high-fat meal while alsoenhancingthe antioxidative capacity of blood.

Extraction efficiency of hydrophilic and lipophilic antioxidants from lyophilized foods using pressurized liquid extraction and manual extraction.

The efficient extraction of antioxidants from food samples is necessary in order to accurately measure their antioxidant capacities. α-Tocopherol and gallic acid were spiked into samples of 5 lyophilized and pulverized vegetables and fruits (onion, cabbage, Satsuma mandarin orange, pumpkin, and spinach). The lipophilic and hydrophilic antioxidants in the samples were sequentially extracted with a mixed solvent of n-hexane and dichloromethane, and then with acetic acid-acidified aqueous methanol. Duplicate samples were extracted: one set was extracted using an automated pressurized liquid extraction apparatus, and the other set was extracted manually. Spiked α-tocopherol and gallic acid were recovered almost quantitatively in the extracted lipophilic and hydrophilic fractions, respectively, especially when pressurized liquid extraction was used. The expected increase in lipophilic oxygen radical absorbance capacity (L-ORAC) due to spiking with α-tocopherol, and the expected increase in 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and total polyphenol content due to spiking with gallic acid, were all recovered in high yield. Relatively low recoveries, as reflected in the hydrophilic ORAC (H-ORAC) value, were obtained following spiking with gallic acid, suggesting an interaction between gallic acid and endogenous antioxidants. The H-ORAC values of gallic acid-spiked samples were almost the same as those of postadded (spiked) samples. These results clearly indicate that lipophilic and hydrophilic antioxidants are effectively extracted from lyophilized food, especially when pressurized liquid extraction is used.

Effect of a walnut meal on postprandial oxidative stress and antioxidants in healthy individuals

BackgroundIn vitro studies rank walnuts (Juglans regia) among the plant foods high in antioxidant capacity, but whether the active constituents of walnuts are bioavailable to humans remains to be determined. The intention of this study was to examine the acute effects of consuming walnuts compared to refined fat on meal induced oxidative stress. At issue is whether the ellagitannins and tocopherols in walnuts are bioavailable and provide postprandial antioxidant protection.MethodsA randomized, crossover, and controlled-feeding study was conducted to evaluate a walnut test meal compared to one composed of refined ingredients on postprandial serum antioxidants and biomarkers of oxidative status in healthy adults (n = 16) with at least 1 week between testing sessions. Following consumption of a low phenolic diet for one day and an overnight fast, blood was sampled prior to the test meals and at intervals up to 24 hours post ingestion and analyzed for total phenols, malondiadehyde (MDA), oxidized LDL, ferric reducing antioxidant power (FRAP), hydrophilic and lipophilic oxygen radical absorbance capacity (ORAC), uric acid, catechins and urinary excretion of phenylacetate metabolites and of urolithin A.ResultsMixed linear models demonstrated a diet effect (P < 0.001) for plasma γ-tocopherol but not for α-tocopherol with the walnut meal. Following the walnut test meal, the incremental 5 hour area under the curve (AUC0-5h) was reduced 7.4% for MDA, increased 7.5% for hydrophilic and 8.5% for lipophilic ORAC and comparable for total phenols, FRAP and uric acid. Oxidized LDL was reduced at 2 hours after the walnut meal. Plasma concentrations of gallocatechin gallate (GCG), epicatechin gallate (ECG) and epicallocatechin gallate (EGCG) increased significantly at 1 hour after the walnut test meal. Quantities of urolithin-A excreted in the urine were significantly higher following the walnut meal.ConclusionsCompared to the refined control meal, the walnut meal acutely increased postprandial γ-tocopherol and catechins and attenuated some measures of oxidative stress.

Determination of Total Antioxidant Capacity by Oxygen Radical Absorbance Capacity (ORAC) Using Fluorescein as the Fluorescence Probe: First Action 2012.23

An improved method for the measurement of oxygen radical absorbance capacity (ORAC) was developed and validated using fluorescein (3',6'-dihydroxyspiro[isobenzofuran-1[3H], 9'[9H]-xanthen]-3-one) as a new fluorescence probe (ORAC(FL)). Randomly methylated beta-cyclodextrin (RMCD) was introduced as the water-solubility enhancer for lipophilic antioxidants. 7% RMCD (w/v) in 50% acetone-H2O mixture sufficiently solubilized vitamin E compounds and other lipophilic phenolic antioxidants in 75 mM phosphate buffer (pH 7.4). Results indicated that fluorescein shows excellent photostability under the plate reader conditions. This ORAC(FL) was validated through linearity, precision, accuracy, and ruggedness. The validation results demonstrated that the ORACFL assay is reliable and robust. The mean of intraday and interday CVs were <15%; for hydrophilic ORAC, LOD and LOQ are 5 and 6.25 microM, respectively; for lipophilic ORAC, LOD and LOQ are 6.25 and 12.5 microM, respectively. It is concluded that unlike other popular methods, the ORAC(FL) assay provides a direct measure of total antioxidant capacity against the peroxyl radicals.

Improvement of the Lipophilic-Oxygen Radical Absorbance Capacity (L-ORAC) Method and Single-Laboratory Validation

We improved the procedure for lipophilic-oxygen radical absorbance capacity (L-ORAC) measurement for better repeatability and intermediate precision. A sealing film was placed on the assay plate, and glass vials and microdispensers equipped with glass capillaries were used. The antioxidant capacities of food extracts can be evaluated by this method with nearly the same precision as antioxidant solutions.

Antioxidant Capacity and Polyphenol Content of Extracts from Crops Cultivated in Japan, and the Effect of Cultivation Environment

Oxygen radical absorbance capacity (ORAC) value and polyphenol contents of extracts from 71 crops cultivated in Japan were determined. Hydrophilic ORAC values (H-ORAC) ranged from 194 − 29,830 μmol TE/100 g fresh weight (FW), whereas lipophilic ORAC values (L-ORAC) ranged from 6 − 2,076 μmol TE/100 g FW. High total ORAC value was indicated in the following vegetables and fruits: mulukhiya (Corchorus olitorius), perilla (Perilla frutescens), water spinach (Ipomoea aquatica), edible burdock (Arctium lappa), blueberries (Vaccinium corymbosum) and hardy kiwifruit (Actinidia arguta) (6,562 − 31,802 μmol TE/100 g FW). These extracts showed a strong positive correlation between ORAC value and polyphenol content (r = 0.98). In addition, to gain a better understanding of ORAC variability in Japanese crops, we also discussed the influence of environmental factors on the ORAC value of stem mustard (Brassica juncea) “Umino” grown in three different regions. Regional variations of ORAC in stem mustard likely result from different levels of ultraviolet radiation and fertilizer application regimens specific to those regions.

Oxidative stability of O/W and W/O/W emulsions: Effect of lipid composition and antioxidant polarity

The effect of storage temperature (65°C, 48h) on the oxidative stability of a food-grade water-in-oil-in-water (W/O/W) emulsion was studied by comparison with an oil-in-water (O/W) emulsion. The emulsions were prepared with linseed oil or olive oil, and in each case, two antioxidants were evaluated, an aqueous Melissa lyophilized extract and BHA. Emulsions were characterized using bright field light microscopy and the oxidation was monitored by measuring the lipid hydroperoxides, thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and trienes (CT), alpha-tocopherol and Lipophilic Oxygen Radical Absorbance Capacity (L-ORACFL) Assay.A great stability of olive oil emulsions was observed, without noticing differences between antioxidants or type of emulsion. This behavior was not observed in linseed oil emulsions. In this case the lipophilic antioxidant (BHA) seemed to be more efficient delaying the lipid oxidation in W/O/W emulsions than the water Melissa extract while the opposite occurs in the O/W emulsion. The type of antioxidant is a key factor in controlling oxidation in W/O/W and O/W emulsions which are prepared with highly polyunsaturated oils, but not in the case of highly monounsaturated ones.

A Comparison of Antioxidant Properties in Organic and Conventional Blueberries

&lt;em&gt;Vacciniumcyanococcus&lt;/em&gt;, most commonly known as blueberry, is a fruit native to North America that is known for its unique taste and high antioxidant content. The skin, seed and juice of both organically and conventionally grown blueberry extract were analyzed for antioxidant content using both the Hydrophilic and Lipophilic Oxygen Radical Absorbance Capacity (ORAC) assays. Results from the Hydrophilic ORAC test showed that conventionally grown blueberries had a higher antioxidant capacity across all samples, while the Lipophilic ORAC assay showed that the antioxidant concentration of organically cultivated blueberry juice was highest, but conventionally grown blueberry seed and skin extract showed higher antioxidant content. The vitamin C content of both conventional and organic blueberries was analyzed using High Performance Liquid Chromatography (HPLC), where the organic blueberries showed a higher vitamin C concentration. In general, both organic and conventional blueberries are rich in antioxidants, and therefore, possess potential health benefits that require further study.

Abstract 5437: Blueberries: Conventional cancer prevention

Abstract Coronary heart disease and cancer, besides remaining the two leading causes of death in the United States, share another common trait: they can both be attributed to lifestyle choices that increase their risk. Epidemiological studies suggest that the consumption of both an antioxidant and phytochemical-rich diet contribute towards the reduction of heart disease and several cancer types. There has been a substantial amount of interest in Vaccinium corymbosum, also known as blueberries, due to their high antioxidant levels which have been show to help prevent cancer of the colon, breast, and prostate. Blueberries exhibit a high content of both phytochemicals such as flavonoids and tannins; and antioxidants such as phenolic acid and resveratrol. Antioxidants provide protection against oxidative stress, a condition that has been suggested to contribute to a variety of diseases, including atherosclerosis, Parkinson's disease, and cancer. The purpose of this study was to explore the health benefits of organic vs. conventional blueberry consumption by comparing the antioxidant content of their individual components, including pulp, skin, seed, and juice using both the Hydrophilic Oxygen Radical Absorbance Capacity (H-ORAC) and the Lipophilic Oxygen Radical Absorbance Capacity (L-ORAC) assay. High-Performance Liquid Chromatography (HPLC) was also used to identify and quantify the amount of Vitamin C in both the organic and conventional blueberries. Blueberry samples were obtained from local distributors and the assays were replicated with five different lots of blueberries. Results indicated that conventional blueberries (33,388 TE/100g pulp, seed, skin and 607,700 TE/L juice) have higher antioxidant levels than organic blueberries (25,800 TE/100g pulp, seed, skin and 415,608 TE/L juice) across all samples. Conversely, HPLC determined a slightly higher Vitamin C content in the organically grown blueberries (592.879 μg/g) compared to conventional blueberries (386.947 μg/g). These results suggest that conventional blueberries may have a higher health benefit potential in preventing cancer and many other degenerative diseases that plague the world. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5437. doi:1538-7445.AM2012-5437

Food‐frequency questionnaire‐based estimates of total antioxidant capacity and risk of non‐Hodgkin lymphoma

Antioxidants, primarily from fruits and vegetables, have been hypothesized to protect against non-Hodgkin lymphoma (NHL). The oxygen radical absorbance capacity (ORAC) assay, which measures total antioxidant capacity of individual foods and accounts for synergism, can be estimated using a food-frequency questionnaire (FFQ). We tested the hypothesis that higher intake of antioxidant nutrients from foods, supplements and FFQ-based ORAC values are associated with a lower risk of NHL in a clinic-based study of 603 incident cases and 1,007 frequency-matched controls. Diet was assessed with a 128-item FFQ. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals adjusted for age, sex, residence and total energy. Dietary intake of α-tocopherol (OR=0.50; p-trend=0.0002), β-carotene (OR=0.58; p-trend=0.0005), lutein/zeaxanthin (OR=0.62; p-trend=0.005), zinc (OR=0.54; p-trend=0.003) and chromium (OR=0.68; p-trend=0.032) was inversely associated with NHL risk. Inclusion of supplement use had little impact on these associations. Total vegetables (OR=0.52; p-trend<0.0001), particularly green leafy (OR=0.52; p-trend<0.0001) and cruciferous (OR=0.68; p-trend=0.045) vegetables, were inversely associated with NHL risk. NHL risk was inversely associated with both hydrophilic ORAC (OR=0.61, p-trend=0.003) and lipophilic ORAC (OR=0.48, p-trend=0.0002), although after simultaneous adjustment for other antioxidants or total vegetables, only the association for lipophilic ORAC remained significant. There was no striking heterogeneity in results across the common NHL subtypes. Higher antioxidant intake as estimated by the FFQ-ORAC, particularly the lipophilic component, was associated with a lower NHL risk after accounting for other antioxidant nutrients and vegetable intake, supporting this as potentially useful summary measure of total antioxidant intake.

A High Antioxidant Spice Blend Attenuates Postprandial Insulin and Triglyceride Responses and Increases Some Plasma Measures of Antioxidant Activity in Healthy, Overweight Men

There is much interest in the potential of dietary antioxidants to attenuate in vivo oxidative stress, but little characterization of the time course of plasma effects exists. Culinary spices have demonstrated potent in vitro antioxidant properties. The objective of this study was to examine whether adding 14 g of a high antioxidant spice blend to a 5060-kJ (1200 kcal) meal exerted significant postprandial effects on markers of plasma antioxidant status and metabolism. Healthy overweight men (n= 6) consumed a control and spiced meal in a randomized crossover design with 1 wk between testing sessions. Blood was sampled prior to the meal and at 30-min intervals for 3.5 h (total of 8 samples). Mixed linear models demonstrated a treatment × time interaction (P< 0.05) for insulin and TG, corresponding with 21 and 31% reductions in postprandial levels with the spiced meal, respectively. Adding spices to the meal significantly increased the ferric reducing antioxidant power, such that postprandial increases following the spiced meal were 2-fold greater than after the control meal (P= 0.009). The hydrophilic oxygen radical absorbance capacity (ORAC) of plasma also was increased by spices (P= 0.02). There were no treatment differences in glucose, total thiols, lipophilic ORAC, or total ORAC. The incorporation of spices into the diet may help normalize postprandial insulin and TG and enhance antioxidant defenses.

Serum antioxidant capacity in head and neck cancer patients receiving chemoradiation therapy.

Measurements of in vivo antioxidant capacity might help to resolve a controversy about the safety of antioxidant supplements during concurrent chemoradiation therapy for cancers of the head and neck. Some data suggest that antioxidant supplements chemoradiation therapy may reduce treatment toxicities; other evidence indicates they may protect tumor cells from oxidative damage. The study defined serum antioxidant capacity before, during and after outpatient therapy. Total, hydrophilic and lipophilic oxygen radical absorbance capacity was measured in serum using the ORACFL microplate method. The procedure is based on the inhibition of peroxyl radical‐ induced oxidation initiated by thermal decomposition of azo‐compounds using fluorescein as the fluorescent probe. The median age of the subjects (n=27) was 58. Forty four percent took supplements. Most were smokers and reported smoking during therapy. Quantifying antioxidant intakes was complicated by treatment toxicities. Total (P=0.0081) and hydrophilic (P=0.0222) antioxidant capacity declined significantly between the pretreatment and end of radiation visits; no changes were detected in the lipophilic fraction. There was, however, marked interindividual variability in the temporal patterns of the lipophilic fraction. To our knowledge, this is the first report of antioxidant capacity in cancer patients receiving similar treatments.

Effect of a pecan meal on postprandial plasma concentrations of hydro‐ and lipophilic oxygen radical absorbance capacity (ORAC) in human volunteers

ObjectivePecans (Carya illinoinensis) are rich in phenolic substances which may contribute to the body's antioxidant defenses. The objective of this study was to determine the effect of pecans on postprandial antioxidant responses.MethodsTest meals containing 100g whole pecans, 100g ground pecans, or an energy‐equivalent amount of refined olive oil as control were administered in a randomized crossover design to 16 healthy volunteers with a 1‐week washout. Plasma was sampled at baseline and at intervals up to 24 hours after consumption of the test meal. Oxygen radical absorbance capacity (ORAC) assays were carried out using the procedure described by Prior et al. (2003). Mixed model analyses of data were performed using SAS version 9.2.ResultsLeast square means±SE for the 5‐hour area under the curve (AUC) after the whole pecan, ground pecan and control meals were 80.0±3, 77.2±3.0, 72.8±8 mmol·h/L trolox equivalents for hydrophilic; and 415±16, 412±16, 374±16 mmol·h/L trolox equivalents for lipophilic components, respectively. Both hydrophilic and lipophilic ORAC values increased about 10% (p&lt;0.001) following the whole pecan test meals.ConclusionAlthough modest, the increases in plasma antioxidant capacity following pecan consumption may be physiologically important and further study is needed.Funding: National Pecan Shellers Association

The validity and reproducibility of food-frequency questionnaire–based total antioxidant capacity estimates in Swedish women

BackgroundTotal antioxidant capacity (TAC) provides an assessment of antioxidant activity and synergistic interactions of redox molecules in foods and plasma. ObjectiveWe investigated the validity and reproducibility of food-frequency questionnaire (FFQ)–based TAC estimates assessed by oxygen radical absorbance capacity (ORAC), total radical-trapping antioxidant parameters (TRAP), and ferric-reducing antioxidant power (FRAP) food values. DesignValidity and reproducibility were evaluated in 2 random samples from the Swedish Mammography Cohort. Validity was studied by comparing FFQ-based TAC estimates with one measurement of plasma TAC in 108 women (54–73-y-old dietary supplement nonusers). Reproducibility was studied in 300 women (56–75 y old, 50.7% dietary supplement nonusers) who completed 2 FFQs 1 y apart. ResultsFruit and vegetables (mainly apples, pears, oranges, and berries) were the major contributors to FFQ-based ORAC (56.5%), TRAP (41.7%), and FRAP (38.0%) estimates. In the validity study, whole plasma ORAC was correlated (Pearson) with FFQ-based ORAC (r = 0.35), TRAP (r = 0.31), and FRAP (r = 0.28) estimates from fruit and vegetables. Correlations between lipophilic plasma ORAC and FFQ-based ORAC, TRAP, and FRAP estimates from fruit and vegetables were 0.41, 0.31, and 0.28, and correlations with plasma TRAP estimates were 0.31, 0.30, and 0.28, respectively. Hydrophilic plasma ORAC and plasma FRAP values did not correlate with FFQ-based TAC estimates. Reproducibility, assessed by intraclass correlations, was 0.60, 0.61, and 0.61 for FFQ-based ORAC, TRAP, and FRAP estimates, respectively, from fruit and vegetables. ConclusionsFFQ-based TAC values represent valid and reproducible estimates that may be used in nutritional epidemiology to assess antioxidant intake from foods. Further studies in other populations to confirm these results are needed.