Mary Harris

Antioxidant Properties of Bran Extracts from Trego Wheat Grown at Different Locations

The effects of growing conditions during the grain-filling period, including high temperature stress, total solar radiation, and average daily solar radiation, on the antioxidant properties of Trego wheat were evaluated. Bran extracts were prepared from Trego wheat, grown at four nonirrigated and one irrigated location in Colorado, and compared for their radical scavenging activities against ABTS*+ and DPPH*, Fe(2+) chelating capacities, and total phenolic contents. Significant differences in radical scavenging activities, chelating capacities, and total phenolic contents were detected among Trego bran samples grown at different locations, suggesting that growing conditions may influence the antioxidant properties of wheat. The bran sample obtained from Fort Collins had the strongest scavenging activity against either ABTS*+ or DPPH* radicals and the greatest chelating activity, whereas the highest total phenolic content was detected in bran samples from Walsh, indicating that each antioxidant activity may respond to the environmental changes differently. Positive correlations were detected between the DPPH* scavenging activity and either total solar radiation (r = 0.97, p = 0.03) or average daily solar radiation (r = 0.97, p = 0.03). In addition, HPLC analysis detected the presence of ferulic, syringic, vanillic, p-hydroxybenzoic, and coumaric acids in wheat bran. Additional research is needed to further investigate the effects of environmental conditions and the interactions between genotype and environmental factors on the antioxidant properties of wheat to promote the production of wheat with improved antioxidant properties by optimizing the growing conditions for a selected genotype.

Antioxidant properties of hard winter wheat extracts

Abstract Extracts from three winter wheat varieties (‘Trego’, ‘Akron’ and ‘Platte’) were evaluated and compared to α-tocopherol for their inhibitory effects on lipid peroxidation in fish oils by measuring the oil stability index (OSI). Free radical scavenging capacities and chelating potencies were also measured to better understand the potential mechanism(s) of their effects on lipid peroxidation. Trego extracts showed the greatest capacity to suppress lipid peroxidation in fish oils. The OSI time of the oil sample containing 600 ppm Trego extract was 2.85 h beyond the control sample containing no antioxidant, which is 3.1 times longer than the OSI time of oil containing 300 ppm tocopherol. Dose effects were observed for Trego extract, but not for Akron or Platte extracts. Furthermore, the higher level of Platte extract corresponded to a shorter OSI time. All three wheat extracts directly reacted with and quenched DPPH radicals and showed chelating activity. Akron extract had the greatest radical scavenging and chelating activities. Neither radical scavenging nor chelating activities of the wheat extracts can explain the relative activities of these extracts on lipid peroxidation in fish oils under the experimental conditions. The results of this study indicate possibility of to developing natural food antioxidants from selected wheat varieties, including Trego hard white winter wheat.

The Role of n-3 Fatty Acids in Gestation and Parturition

Preterm birth is the most common cause of low infant birth weight and infant morbidity and mortality. Evidence from human and animal studies indicates that essential fatty acids of both the n-3 and n-6 series, and their eicosanoid metabolites, play important and modifiable roles in gestational duration and parturition, and n-3 fatty acid intake during pregnancy may be inadequate. Prostaglandins (PG) of the 2-series are involved in parturition and connective tissue remodeling associated with cervical maturation and rupture of membranes. In the absence of infections, preterm birth is characterized by lower reproductive tissue PG production and decreased inducible cyclooxygenase expression. Women who deliver prematurely have increased pools of n-6 fatty acid and decreased n-3 fatty acids, despite the lower PG production. Several human pregnancy supplementation trials with n-3 fatty acids have shown a significant reduction in the incidence of premature deliver and increased birth weight associated with increased gestational duration. Supplementation with long chain n-3 fatty acids such as docosahexaenoic acid may be useful in prolonging the duration of gestation in some high-risk pregnancies. Evidence presented in this review is discussed in terms of the roles of dietary n-3 and n-6 fatty acids in gestation and parturition, mechanisms by which they may influence gestational duration and the human trials suggesting that increased dietary long-chain n-3 fatty acids decrease the incidence of premature delivery.

Postexercise energy expenditure and substrate oxidation in young women resulting from exercise bouts of different intensity.

OBJECTIVE The effects of low and high intensity exercise, of similar energy output, on exercise and post-exercise energy expenditure and substrate oxidation were studied in eight active, eumenorrheic females (aged 22 to 31). METHODS Continuous indirect calorimetry was performed during cycle ergometry exercise and for 3 hours following each of the following three protocols administered in random order: 1) low intensity exercise (LIE: 500 calories 50% VO2 max), 2) high intensity exercise (HIE: 500 calories 75% VO2 max), and 3) control condition (C) of quiet sitting for 1 hour, rather than exercise. Excess postexercise oxygen consumption (EPOC), energy expenditure and total fat and carbohydrate oxidation for the entire exercise/control plus 3-hour recovery period were determined by indirect calorimetry. RESULTS Mean EPOC for the 3-hour post-exercise period for HIE (9.0 +/- 1.7 L, 41 kcals) was significantly greater than EPOC for low intensity exercise (4.8 +/- 1.6 L, 22 kcals). Oxygen consumption (VO2) following HIE, but not LIE remained elevated at the end of the 3-hour post-exercise period. Total carbohydrate oxidation (exercise plus postexercise period) was significantly higher for HIE (116 +/- 8.6 g) compared to LIE (85.0 +/- 5.2 g). Total fat oxidation was lower for HIE (27.7 +/- 3.3 g) compared to LIE (36.9 +/- 3.0 g), but this difference did not reach statistical significance (p = 0.07). At the end of the 3-hour recovery period, the rate of fat oxidation was higher following HIE compared to LIE. CONCLUSION These data indicate that the recovery period should also be considered when determining the impact of different exercise intensities on total energy expenditure and fat and carbohydrate utilization in women.

The Omega-3 Story:: Nutritional Prevention of Preterm Birth and Other Adverse Pregnancy Outcomes

Healthy intrauterine growth and development, appropriately timed parturition, and safe birth continue to be critical determinants of each child’s chances of achieving their full biological potential. Essential fatty acids (EFAs) and their metabolites are involved in the synthesis of eicosanoids that play essential and multifaceted roles in human reproduction, especially during pregnancy, parturition, and lactation. Fatty acid-derived prostaglandins (PGs), hydroxyeicosatetraenoic molecules (HETE), leukotrienes (LTs), thromboxanes (TXs), and prostacyclins (PIs) play well-documented “final common pathway” molecular roles in both normal term labor as well as in preterm parturition (1). Abnormalities of thromboxane and prostacyclin physiology also occur with preeclampsia, eclampsia, and pregnancy-induced hypertension (PIH), which often require preterm delivery (2). Docosahexaenoic acid (22: 6v-3, DHA) and other EFA derivatives are important components of the rapidly growing brain and retinal tissues of the perinate (3). DHA, a long-chain omega-3 (v-3) fatty acid (LCPUFA) is expressed in breast milk, and breast-fed and DHA-nutritionally supplemented children demonstrate improved performance on various tests of brain and vision functioning (4). Ensuring maternal and perinatal nutritional sufficiency during pregnancy and lactation is investigated increasingly as an effective and inexpensive strategy for optimizing pregnancy and lactational outcome (5). Informed families and providers are invested both in preventing the occurrence and consequences of prematurity and inadequate uterine growth (6). Families and providers are similarly interested in optimizing healthy growth and development of the fetus’ developing organs, especially brain, retina, and the cardiovascular system (7). Preterm birth continues to cause neonatal morbidity and life time disabilities (8). Preterm birth is associated with potentially immense direct and indirect costs, as well as liabilities for care providers. Preterm birth is best understood as a syndrome caused by numerous diseases such as intrauterine infection and inflammation, uterine over-distention or intrauterine bleeding. Such causes of prematurity are best considered as “complex diseases.” Complex diseases involve interactions between multiple bodily systems or parameters including nutrition, immunity, coagulation, and the endocrine system. For example, the fetus depends on maternal nutrients, such as EFAs, for multiple bodily functions including eicosanoid metabolism as well as brain growth and retinal development. Thus, if the mother is deficient in certain fatty acids, this deficiency tends to be compounded in the fetus (9). Such complex disease processes are best dealt with using primary prevention techniques—such as ensuring nutritional sufficiency, particularlyv-3 LCPUFA sufficiency, during pregnancy and lactation.

Expanded Health Belief Model Predicts Diabetes Self-Management in College Students

An instrument was designed to determine relationships between constructs of the Expanded Health Belief Model and to identify characteristics of college students who successfully manage their diabetes. The Diabetes College Scale was developed to measure attitudes and behaviors pertinent to diabetes management and college life. It was tested for content validity, test-retest reliability, and internal consistency. Data were collected from college students using a cross-sectional design. Campus health care providers were invited via electronic mail to administer the survey to students with Type I diabetes. Ninety-eight questionnaires were mailed to interested providers, of which 86 (88%) were returned. Mean scores for attitude constructs, seven behaviors, and two outcomes were measured. Twenty-six experts established content validity. Instrument reliability was evaluated using paired t-tests, Cronbachs alpha, and correlation coefficients. Correlation coefficients and stepwise multiple regression analysis evaluated relationships among variables measured. Intention and emotional response were strong predictors of exercise, whereas health importance and intention were predictive of testing blood sugar. Situational factors and emotional response were substantial barriers to optimal diabetes self-care. College health care providers should address these areas in providing services to this population. Additional testing of the instrument is also recommended.

Cardiovascular Disease Risk Factors are Lower in African-American Vegans Compared to Lacto-Ovo-vegetarians

OBJECTIVE This study was undertaken to determine if African-American strict vegetarians (vegans) exhibit lower blood pressure (BP) and a more favorable serum lipid profile than their lacto-ovo vegetarian (LOV) counterparts, and if plasma ascorbic acid (AA) concentrations could explain any group differences in these cardiovascular disease (CVD) risk factors. METHODS Habitual dietary intake, anthropometric characteristics, blood pressure, and blood lipids and ascorbic acid concentrations were determined in African-American study participants (male vegans, n = 14, age = 45.6 years; male LOV, n = 49, age = 49.8; female vegans, n = 31, age = 51.1, female LOV, n = 94, age = 52.1) recruited from Seventh-Day Adventist Churches in several cities in the northeastern United States. RESULTS Body mass index (BMI) was significantly lower in the vegans (24.7 +/- 1.9 kg/m2) compared to LOV (26.4 +/- 0.45 kg/m2). There were no diet or gender differences in BP. Serum total cholesterol (3.75 +/- 0.12 vs. 4.51 +/- 0.10 mmol/L), LDL-cholesterol (2.06 +/- 0.13 vs. 2.65 +/- 0.09 mmol/l), and triglycerides (0.94 +/- 0.07 vs. 1.17 +/- 0.04 mmol/L) were significantly (p < 0.05) lower in vegans compared to LOV, but there were no dietary group differences in HDL-C. The ratio of total to HDL-cholesterol was significantly lower in vegans than in LOV (3.0 +/- 0.13 vs. 3.7 +/- 0.13). There were no dietary group differences in plasma AA concentrations. However, in the entire sample, plasma AA was inversely associated with BP (SBP: r = -0.46, p < 0.001, DBP: r = -0.32, p < 0.001), but unrelated to the serum lipid concentrations. CONCLUSION African-American vegans exhibit a more favorable serum lipid profile than lacto-ovo-vegatarians and plasma AA is inversely related to BP in African-American vegetarians but does not explain any of the differences in CVD risk factors between vegans and lacto-ovo vegetarians.

Risk Factors for Cardiovascular Disease and Diabetes in Two Groups of Hispanic Americans with Differing Dietary Habits

OBJECTIVE The purpose of this study was to determine if Hispanic Seventh-Day Adventists (SDAs), who typically eat a diet lower in fat, saturated fat and protein, and higher in complex carbohydrates and dietary fiber than the usual omnivorous diet, exhibit lower risk factors for cardiovascular disease (CVD) and Type 2 diabetes compared to Hispanic Catholic omnivores. METHODS Anthropometric characteristics, dietary intake, blood pressure, serum lipids, glucose and insulin, as well as plasma ascorbic acid and vitamin E concentrations, were measured in two groups of Hispanic study participants residing in Denver, Colorado: 74 SDA study participants (x age: 42+/-1.5 y) and 45 Catholic participants (x age: 44+/-2.2 y). RESULTS The SDAs reported lower dietary intakes of total fat, saturated fat and cholesterol and higher relative intakes of carbohydrate and dietary fiber compared to their Catholic counterparts. The SDAs exhibited significantly lower body mass index (BMI = 27.2+/-0.6) and waist-to-hip ratios (WHR = 0.84+/-0.01) compared to the Catholics (BMI = 31.4+/-1.1; WHR = 0.88+/-0.01). The SDAs, compared to the Catholics, had lower fasting insulin (11.4+/-0.6 vs. 18.9+/-3.1 microu/ml) and glucose concentrations (88.6+/-1.1 vs. 104.1+/-5.4 mg/dl). The SDA Hispanics, compared to the Catholic Hispanics, exhibited significantly lower values for systolic blood pressure (SBP = 1102 vs. 118+/-3 mm Hg), serum total cholesterol (STC = 198+/-5 vs. 214+/-6 mg/dl) and serum triglycerides (TG = 152+/-12 vs. 232+/-27) and higher serum concentrations of high-density lipoprotein cholesterol (HDL-C = 44.7+/-1.3 vs. 39.1+/-1.4 mg/dl) and ascorbic acid (1.14+/-0.08 vs. 0.87+/-0.07 mg/dl). Low-density lipoprotein cholesterol (LDL-C) and vitamin E concentrations were not significantly different between groups, but the SDAs exhibited lower ratios of STC/HDL-C and LDL-C/HDL-C. CONCLUSION Hispanic American SDAs, who eat a plant-based diet, exhibit a more favorable blood lipid profile, lower blood pressure and lower risk for Type 2 diabetes compared to Hispanic American Catholics, who do not eat a plant-based diet.

Omega-3 for baby and me: material development for a WIC intervention to increase DHA intake during pregnancy.

Objective: The purpose of this project was to develop educational materials for a Speical Supplemental Nutrition Program for Women, Infants, and Children (WIC) program intervention in Denver, Colorado. Despite accumulating evidence of the importance of docosahexaenoic acid (DHA) during pregnancy, there has been no attempt to develop a targeted nutrition intervention to improve birth outcomes among high-risk women. The goal of the Omega-3 for Baby and Me intervention, for which these materials were developed, is to increase the consumption of DHA-rich foods to decrease the risk for premature delivery and low-birth weight babies among this population. Method: Following collection of data from eight focus groups among the target audience, the principles of the Health Belief Model were used to develop materials to address the needs, barriers, and motivators of this audience. In addition, process evaluation pilot testing was used to evaluate recipes and logos during the material development. Results: Materials developed for this intervention include a logo, 9-month calendar, stickers, shopping lists, recipes, recipe holder, magnetic clip, nylon pouch, and recruitment materials. Conclusion: The use of focus groups and pilot testing increased the target audience acceptance of education materials that are being used for the Omega-3 for Baby and Me intervention. Successful outcomes from the Omega-3 for Baby and Me intervention, i.e., decreasing the incidence of preterm birth and low-birth weight, will have implications for supplemental food policies at state and national levels.

Prostaglandins in selected reproductive tissues in preterm and full term gestations

We investigated differences in maternal plasma and trophoblast prostaglandin metabolism associated with preterm births. Tissue prostaglandins (PGs) E2 and F2 alpha and the stable plasma PGF2 alpha metabolite, 13,14-dihydro-15-keto-PGF2 alpha, were measured in preterm (< 37 weeks) and term (< or = 37 weeks) births. Amnion PGE2 in preterm (106.1 +/- 15.7 ng/g wet weight tissue; x +/- SEM; n = 37) was lower than in term (176.6 +/- 22.7 ng/g wet weight; x +/- SEM; n = 34, P < 0.02). Placenta PGE2 was lower in preterm (34.7 +/- 19.7 ng/g wet weight; x +/- SEM) than in term (103.3 +/- 28.0 ng/g wet weight; x +/- SEM, P < 0.04). Preterm PGF2 alpha was consistently lower in the amnion (106.8 +/- 17.5 ng/g wet weight) and placenta (102.5 +/- 8.7 ng/g wet weight) than in term amnion (188.2 +/- 24.8 ng/g wet weight; P < 0.01) and placenta (128.9 +/- 7.8 ng/g wet weight; P < 0.03). Chorionic PGE2 and plasma PGF2 alpha metabolite followed this trend but did not reach significance. These findings suggest qualitative and quantitative differences in maternal and trophoblast eicosanoid metabolism between term and preterm parturition.