Effectiveness of Nutrition Education and Fruit and Vegetable Consumption on Changes in Biomarkers of Inflammation and Oxidative Stress among Overweight and Obese Adults M. G. Wagner1, K. Hert1, L. Myers1, J. Levine2, T. Heck1, Y. Rhee1 1Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, Fargo, ND, 2Family Nutrition Sciences, Concordia College, Moorhead, MN
Abstract • Introduction: The growing prevalence of overweight and obesity among adults is concerning because of the numerous health conditions associated with excess weight. Underlying mechanisms believed to contribute to these detrimental health outcomes are oxidative stress and inflammation. Fortunately, regulation of oxidative stress and inflammation is possible via antioxidants consumed through a diet adequate in fruits and vegetables. However, adults’ consumption of fruits and vegetables is below recommended amounts, which places them at increased risk for chronic diseases. • Purpose: This study was designed to determine the effectiveness of a community-based fruit and vegetable education program and provision of fruits and vegetables on consumption of fruits, vegetables, antioxidants, and changes in biomarkers of inflammation and oxidative stress among overweight and obese adults. • Methods: Forty-seven adults (16 men/31 women; 45.9 ± 11.8 y; body mass index 32.7 ± 7.3 kg/m2) were randomly assigned to one of three intervention groups. The control group received no intervention; the education group attended weekly nutrition education sessions; and the fruit and vegetable group attended weekly nutrition education sessions and received one serving of fruits and two servings of vegetables per day for 10 weeks. Consumption of fruits, vegetables, and antioxidants were assessed using three-day food records. • Results: Changes in consumption of fruits, vegetables, and antioxidants among participants were associated with improvements in biomarkers of inflammation and oxidative stress in those receiving education but not among control group participants. • Discussion: Adequate and varied consumption of fruits and vegetables is recommended to aid in the prevention and regulation of inflammation.
Introduction Rates of overweight and obesity have reached epidemic proportions in the U.S. contributing to increased risk of chronic disease1 An underlying mechanism believed to contribute to these detrimental health outcomes is the inflammatory process2
Introduction • Antioxidant systems in the body are responsible for regulating oxidative stress and subsequent inflammation3 • Because of their high antioxidant content, consumption of fruits and vegetables (FV) is widely encouraged4 • Americans, including overweight and obese adults, consume the recommended FV servings5
Purpose To determine the effectiveness of a community-based fruit and vegetable education program and provision of FV on consumption of fruits, vegetables, antioxidants, and changes in biomarkers of inflammation and oxidative stress among overweight and obese adults
Study protocol approved by the North Dakota State University Institutional Review Board Participants 47 adults Inclusion Age over 18 years BMI > 25 kg/m2 Methods • Exclusion • History of bariatric surgery • Current smoker • Pregnant
Methods • Data Collection • Demographics • Dietary Intake • 3-day Food Record • Laboratory Assessments • Fasting Blood Draw • Thiobarbituric acid reactive substances • Tumor necrosis factor-alpha • C-reactive protein • Study Duration • Pre-testing • 2 weeks • Intervention • 10 weeks • Post-testing • 2 weeks
Methods Statistical Analysis PASW version 18.0 (SPSS Inc., Chicago, IL) Alpha level < .05 Descriptive statistics T tests Pearson correlation Analysis of variance
Demographics Control Education FV Gender Female 5 6 5 Male 3 9 19 Age (y) 42.1 ± 14.2 47.7 ± 10.7 46.0 ± 11.9 BMI (kg/m2) 33.0 ± 11.1 32.5 ± 6.0 32.7 ± 7.1
FruitConsumption * * *Significant difference in mean servings consumed per day from pre-test to post-test
Beta Carotene Consumption ^ ^Trend toward a significant difference in consumption from pre-test to post-test
Thiobarbituric Acid Reactive Substances ^ ^Trend toward a significant difference in consumption from pre-test to post-test
C-Reactive Protein ^ ^Trend toward a significant difference in consumption from pre-test to post-test
Discussion Supplementation was effective at increasing FV consumption. This is the first study to examine effects of FV supplementation on consumption patterns of overweight and obese adults. Decreases in oxidative stress and inflammatory biomarkers were greatest among participants in the FV group, which suggests a possible benefit of FV supplementation on decreased inflammation.3
Conclusions A limitation was that a convenience sample was used, thereby limiting the generalizability of the results. Efforts to increase consumption should focus on encouraging intake of a variety of FV, particularly those with the highest antioxidant content. It is also necessary to emphasize management of overall energy intake, including decreased consumption of high-energy, nutrient poor foods.
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