Wagner, Meredith; Ph.D.
Program of Human Development, Wellness
College of Human Development and Education; North Dakota State University
Effects of Nutrition Education and Fruit and Vegetable Consumption on Knowledge of Antioxidants and Biomarkers of Inflammation and Chronic Disease
Major Professor: Dr. Yeong Rhee
Obesity rates have reached epidemic proportions contributing to the majority of Americans experiencing a state of chronic inflammation. Associations between inflammation, oxidative stress, and increased disease risk contribute to detrimental consequences of obesity. Regulation of inflammation and oxidative stress is possible via antioxidants consumed through a diet adequate in fruits and vegetables but consumption among adults is poor. Previous studies have assessed the impact of fruit, vegetable, and antioxidant consumption on oxidative stress and inflammation among healthy individuals. However, no studies have examined effects of education and fruit and vegetable consumption on markers of oxidative stress, inflammation, and other chronic disease biomarkers in a single study of overweight and obese adults. The purposes of this study were to examine effects of nutrition education and fruit and vegetable consumption on: interest and knowledge related to antioxidants; consumption patterns; weight, body mass index (BMI), body composition, blood lipids, and blood glucose; and biomarkers of oxidative stress and inflammation. Fifty-four adults (19 men/35 women; age 44.7±12.1 y; BMI 33.2±7.7 kg/m2) were randomly assigned to one of three intervention groups. The control group received no intervention, the education group attended weekly nutrition lessons, and the fruit and vegetable group attended weekly nutrition lessons and received one serving of fruits and two servings of vegetables per day for 10 weeks. Fruit and vegetable-related knowledge, attitudes, and behaviors were assessed using questionnaires. Fruit, vegetable, and antioxidant consumption was assessed using semi-quantitative food frequency questionnaires and three-day food records and anthropometric measurements and fasting blood draws were conducted. Results indicated improvements in fruit and vegetable-related knowledge, attitudes, and behaviors and increased consumption of antioxidant-rich fruits and vegetables following nutrition education. Associations existed between increased fruit and vegetable consumption and improvements in LDL cholesterol. However, minimal associations between changes in consumption of fruits, vegetables, and antioxidants and biomarkers of inflammation and oxidative stress were indicated. In order to be effective, nutrition intervention programs need to thoroughly address participants’ fruit and vegetable-related knowledge and attitudes, provide exposure to fruits and vegetables, and promote adequate consumption of antioxidant-rich fruits and vegetables while concurrently emphasizing management of overall energy intake.