Timely Topics

1. TOTAL ANTIOXIDANT CONTENT OF ALTERNATIVES TO REFINED SUGAR

Katherine M. Phillips, Monica H. Carlsen, Rune Blomhoff

Background: Oxidative damage is implicated in the etiology of cancer, cardiovascular disease, and other degenerative disorders. Recent nutritional research has focused on the antioxidant potential of foods, while current dietary recommendations are to increase the intake of antioxidant-rich foods rather than supplement specific nutrients. Many alternatives to refined sugar are available, including raw cane sugar, plant saps/syrups (eg, maple syrup, agave nectar), molasses, honey, and fruit sugars (eg, date sugar). Unrefined sweeteners were hypothesized to contain higher levels of antioxidants, similar to the contrast between whole and refined grain products.

Objective: To compare the total antioxidant content of natural sweeteners as alternatives to refined sugar.

Design: The ferric-reducing ability of plasma (FRAP) assay was used to estimate total antioxidant capacity. Major brands of 12 types of sweeteners as well as refined white sugar and corn syrup were sampled from retail outlets in the United States.

Results: Substantial differences in total antioxidant content of different sweeteners were found. Refined sugar, corn syrup, and agave nectar contained minimal antioxidant activity (<0.01 mmol FRAP/100 g); raw cane sugar had a higher FRAP (0.1 mmol/100 g). Dark and blackstrap molasses had the highest FRAP (4.6 to 4.9 mmol/100 g), while maple syrup, brown sugar, and honey showed intermediate antioxidant capacity (0.2 to 0.7 mmol FRAP/100 g). Based on an average intake of 130 g/day refined sugars and the antioxidant activity measured in typical diets, substituting alternative sweeteners could increase antioxidant intake an average of 2.6 mmol/day, similar to the amount found in a serving of berries or nuts.

Conclusions: Many readily available alternatives to refined sugar offer the potential benefit of antioxidant activity.

Source: Journal of the American Dietetic Association, Vol. 109, N0. 1, 64-71, January 2009.

2. BREASTFEEDING REDUCES POSTPARTUM WEIGHT RETENTION

Jennifer L Baker, Michael Gamborg, Berit L Heitmann, Lauren Lissner, Thorkild IA Sørensen and Kathleen M Rasmussen

¹From the Centre for Health and Society (JLB, MG, BLH, and TIAS) and the Research Unit for Dietary Studies (BLH), Institute of Preventive Medicine, Copenhagen, Denmark; the Sahlgrenska Academy at Göteborg University, Göteborg, Sweden (LL); and the Division of Nutritional Sciences, Cornell University, Ithaca, New York (KMR)

Background: Weight gained during pregnancy and not lost postpartum may contribute to obesity in women of childbearing age.

Objective: We aimed to determine whether breastfeeding reduces postpartum weight retention (PPWR) in a population among which full breastfeeding is common and breastfeeding duration is long.

Design: We selected women from the Danish National Birth Cohort who ever breastfed (>98%), and we conducted the interviews at 6 (n = 36 030) and 18 (n = 26 846) mo postpartum. We used regression analyses to investigate whether breastfeeding (scored to account for duration and intensity) reduced PPWR at 6 and 18 mo after adjustment for maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG).

Results: GWG was positively (P < 0.0001) associated with PPWR at both 6 and 18 mo postpartum. Breastfeeding was negatively associated with PPWR in all women but those in the heaviest category of prepregnancy BMI at 6 (P < 0.0001) and 18 (P < 0.05) mo postpartum. When modeled together with adjustment for possible confounding, these associations were marginally attenuated. We calculated that, if women exclusively breastfed for 6 mo as recommended, PPWR could be eliminated by that time in women with GWG values of ≈12 kg, and that the possibility of major weight gain (≥5 kg) could be reduced in all but the heaviest women.

Conclusion: Breastfeeding was associated with lower PPWR in all categories of prepregnancy BMI. These results suggest that, when combined with GWG values of ≈12 kg, breastfeeding as recommended could eliminate weight retention by 6 mo postpartum in many women.

3. ACUTE STRESS-RELATED CHANGES IN EATING IN THE ABSENCE OF HUNGER

Femke Rutters, Arie G. Nieuwenhuizen, Sofie G.T. Lemmens, Jurriaan M. Born, Margriet S. Westerterp-Plantenga

¹ Department of Human Biology, Maastricht University, Maastricht, The Netherlands

Background: Obesity results from chronic deregulation of energy balance, which may in part be caused by stress.

Objective: Our objective was to investigate the effect of acute and psychological stress on food intake, using the eating in the absence of hunger paradigm, in normal and overweight men and women (while taking dietary restraint and disinhibition into account).

Design: In 129 subjects (BMI = 24.5±3.4 kg/m2 and age = 27.6±8.8 years), scores were determined on the Three Factor Eating Questionnaire (dietary restraint = 7.2±4.4; disinhibition = 4.5±2.6; feeling of hunger = 3.9 ±2.6) and State-Trait Anxiety Inventory (trait score = 31.7±24.2).

Results: In a randomized crossover design, the "eating in absence of hunger" protocol was measured as a function of acute stress vs. a control task and of state anxiety scores. Energy intake from sweet foods (708.1 kJ vs. 599.4 kJ, P < 0.03) and total energy intake (965.2 kJ vs. 793.8 kJ, P < 0.01) were significantly higher in the stress condition compared to the control condition. Differences in energy intake between the stress and control condition were a function of increase in state anxiety scores during the stress task ( state anxiety scores) (R² = 0.05, P < 0.01). This positive relationship was stronger in subjects with high disinhibition scores (R² = 0.12, P < 0.05). Differences in state anxiety scores were a function of trait anxiety scores (R² = 0.07, P < 0.05).

Conclusion: We conclude that acute psychological stress is associated with eating in the absence of hunger, especially in vulnerable individuals characterized by disinhibited eating behavior and sensitivity to chronic stress.

4) AGE AT ARRIVAL AND RISK OF OBESITY AMONG US IMMIGRANTS

Reshma Roshania, K.M. Venkat Narayan, Reena Oza-Frank

¹Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
¹Graduate Division of Biomedical and Biological Sciences, Nutrition and Health Sciences Program, Emory University, Atlanta, Georgia, USA

Background: Although immigrants are a rapidly growing subgroup, little is known about overweight/obesity among the foreign-born in the United States, especially regarding the effect of age at arrival.

Objective: This study determined whether overweight/obesity prevalence is associated with age at arrival of immigrants to the United States.

Design: We analyzed data on 6,421 adult immigrants from the New Immigrant Survey (NIS), a study that is nationally representative of adult immigrants with newly acquired legal permanent residence (LPR). Multiple regression analyses tested the effects of duration of residence and age at arrival on overweight/obesity, defined by BMI of ≥25 kg/m2, and self-reported dietary change score. We found the relationship between duration of residence and overweight/obesity prevalence varied by age at arrival (P < 0.001).

Results: Immigrants ≤20-years old at arrival who had resided in the United States ≥15 years were 11 times (95% confidence interval: 5.33, 22.56) more likely to be overweight/obese than immigrants <20-years old at arrival who had resided in the United States ≤1 year. By comparison, there was no difference in overweight/obesity prevalence by duration among immigrants who arrived at >50 years of age. Higher self-reported dietary change is also associated with overweight/obesity.

Conclusion: In conclusion, immigrants younger than 20 at arrival in the United States may be at higher risk of overweight/obesity with increasing duration of residence than those who arrive at later ages. Obesity prevention among young US immigrants should be a priority.

Source: Obesity, Vol. 16, No.12, 2669–2675, December 2008

5. PHYSICAL ACTIVITY MAY FACILITATE DIABETES PREVENTION IN ADOLESCENTS

Amy S. Thomas, Lori F. Greene, Jamy D. Ard, Robert A. Oster, Betty E. Darnell, Barbara A. Gower

¹Department of Nutrition Science, University of Alabama at Birmingham, Birmingham, Alabama
²Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
³General Clinical Research Center, University of Alabama at Birmingham, Birmingham, Alabama

Objective: The aim of this study was to examine the association of physical activity with glucose tolerance and resting energy expenditure (REE) among adolescents.

Design: Subjects were 32 male and female adolescents aged 12–18 years. Intravenous glucose tolerance (K_g) and REE were assessed under inpatient conditions after an overnight fast. Kg was determined as the inverse slope of time versus (ln) glucose over minutes 8–19 of an intravenous glucose tolerance test. Physical activity was assessed over 8 days using accelerometry (counts per minute).

Results: In multiple linear regression analysis, K_g was positively associated with total physical activity (TPA), moderate physical activity (MPA), and 5-min bouts of MPA. Similarly, REE was positively associated with TPA, MPA, and 5-min bouts of MPA.

Conclusions: In this population, physical activity was positively related to both glucose tolerance and REE. These results suggest that moderate activity may be beneficial in the prevention of diabetes in adolescent populations both through promoting efficient glucose disposal and through increasing energy expenditure.

David J. A. Jenkins, Cyril W. C. Kendall, Gail McKeown-Eyssen, Robert G. Josse, Jay Silverberg, Gillian L. Booth, Edward Vidgen, Andrea R. Josse, Tri H. Nguyen, Sorcha Corrigan, Monica S. Banach, Sophie Ares, Sandy Mitchell, Azadeh Emam, Livia S. A. Augustin, Tina L. Parker, Lawrence A. Leiter

Background: Clinical trials using antihyperglycemic medications to improve glycemic control have not demonstrated the anticipated cardiovascular benefits. Low–glycemic index diets may improve both glycemic control and cardiovascular risk factors for patients with type 2 diabetes but debate over their effectiveness continues due to trial limitations.

Objective: To test the effects of low–glycemic index diets on glycemic control and cardiovascular risk factors in patients with type 2 diabetes.

Design: A randomized, parallel study design at a Canadian university hospital research center of 210 participants with type 2 diabetes treated with antihyperglycemic medications who were recruited by newspaper advertisement and randomly assigned to receive 1 of 2 diet treatments each for 6 months between September 16, 2004, and May 22, 2007.

Results: In the intention-to-treat analysis, HbA_1c decreased by –0.18% absolute HbA_1c units (95% confidence interval [CI], –0.29% to –0.07%) in the high–cereal fiber diet compared with –0.50% absolute HbA1c units (95% CI, –0.61% to –0.39%) in the low–glycemic index diet (P < .001). There was also an increase of high-density lipoprotein cholesterol in the low–glycemic index diet by 1.7 mg/dL (95% CI, 0.8-2.6 mg/dL) compared with a decrease of high-density lipoprotein cholesterol by –0.2 mg/dL (95% CI, –0.9 to 0.5 mg/dL) in the high–cereal fiber diet (P = .005). The reduction in dietary glycemic index related positively to the reduction in HbA_1c concentration (r = 0.35, P < .001) and negatively to the increase in high-density lipoprotein cholesterol (r = –0.19, P = .009).

Conclusions: In patients with type 2 diabetes, 6-month treatment with a low–glycemic index diet resulted in moderately lower HbA1c levels compared with a high–cereal fiber diet.
Source: JAMA, Vol. 300, No. 23,2742-2753, December 2008