Dr. Jahns joined the Grand Forks Human Nutrition Research Center in January, 2009. She came to Grand Forks from Knoxville, TN, where she was an Assistant Professor of Public Health Nutrition in the Department of Nutrition at The University Of Tennessee. Dr. Jahns completed a bachelors degree in Dietetics at Texas Christian University, Ft. Worth, TX, in 1998 and a Ph.D. in Nutritional Epidemiology at The University of North Carolina, Chapel Hill, NC, in 2004. She is a Registered Dietitian.
Dr. Jahns combines nutritional epidemiologic methods with laboratory-based studies and randomized controlled community feeding trials to answer questions about compliance with the Dietary Guidelines for Americans (DGA), with a particular emphasis on vegetable intake. She also studies the use of skin carotenoid status to measure changes in vegetable and fruit intake. Current projects include a randomized controlled trial seeking to increase the reinforcing value of vegetables in the diet.
Validated the use of skin carotenoid status as a biomarker of change in vegetable and fruit intake. Dr. Jahns was the first to demonstrate in a clinical feeding trial that skin carotenoid status as measured by resonance Raman spectroscopy closely follows blood carotenoid concentration during depletion and repletion of consumption of carotenoid-rich vegetables and fruits. This groundbreaking research demonstrated the validity of skin carotenoid assessment, making it the first non-invasive method for assessing carotenoid status with direct application to studies of DGA, e.g., the impact of federal food assistance programs and other efforts to increase vegetable and fruit intakes of Americans. http://www.ncbi.nlm.nih.gov/pubmed/25008856.
Described the quality of the mix of foods advertised in grocery store sales circulars. Dr. Jahns was the first to document the contents of a full year of grocery store Sunday sales circulars to investigate seasonal differences in types of DGA food group recommendations (MyPlate) and HEI-2010 diet quality scores. Very few seasonal differences were found in food groups or diet quality scores. The overall diet quality score of the circulars was lower than that of the dietary intake of the US population. Opportunities exist to increase the advertising of locally-grown, seasonal whole vegetables and fruits in addition to canned and frozen varieties. http://www.ncbi.nlm.nih.gov/pubmed/25249348 and http://www.ncbi.nlm.nih.gov/pubmed/26508588.
Served as site director for the multi-site USDA-ARS Healthy Eating and Lifestyle for Total Health (HEALTH) study. Dr. Jahns was the Northern Plains site director and conducted Nominal Group Technique sessions to investigate barriers and facilitators to following the DGA in 5th grade children and unrelated caregivers. The information was used to create a survey that was then pilot-tested in 800 child and parent dyads. The results will be used to directly inform the development of new DGAs. http://www.ncbi.nlm.nih.gov/pubmed/27194306 and http://www.ncbi.nlm.nih.gov/pubmed/23871110.
Described barriers and facilitators to following the DGA on a rural, Northern Plains American Indian reservation. Dr. Jahns was the first to investigate dietary guideline adherence in a tribal community and found that while many barriers were personal, such as lack of time or not liking a food (e.g. vegetables), there were many environmental barriers such as cost and lack of access on the reservation. Barriers to being physically active included extreme weather conditions and threat from stray dogs. http://www.ncbi.nlm.nih.gov/pubmed/24679830 and http://www.ncbi.nlm.nih.gov/pubmed/25421064.