Date Available


Year of Publication


Degree Name

Master of Science in Nutrition and Food Systems (MSNFS)

Document Type

Master's Thesis


Agriculture, Food and Environment


Dietetics and Human Nutrition

First Advisor

Dr. Kyle Flack


Background: Traditional obesity treatment is ineffective as rates are still on the rise, thus necessitating novel treatments. Plasma bilirubin, once thought as only a clinical marker of liver disease, is now considered an important hormone, correlated with better outcomes within certain metabolic disease states such as cardiovascular disease and diabetes. This is largely due to bilirubin’s role in promoting fatty acid oxidation via its interaction with PPARα and its antioxidant capacities to reduce lipid peroxidation. Possible methods of mildly increasing plasma bilirubin may provide a novel obesity treatment. Objective: To evaluate if Silmarin supplementation via milk thistle, exercise, or a combination of the two can increase plasma bilirubin. This study also tested the hypothesis that increases in plasma bilirubin are correlated with decreases in body fat mass. Methods: Male and female adults with obesity (BMI > 30.0, N=19) were split into 4 groups and participated in a 12-week intervention. Participants were assigned either Milk Thistle or a Placebo supplement condition, and either an exercise (participate in a 12-week aerobic exercise program) or sedentary control (engage in no structured exercise) condition. Fasting blood samples were collected and body composition assessments (BodPod) were performed pre and post intervention. Results: Trends were observed for the Silmarin supplementation + Exercise group for increasing plasma bilirubin and decreasing fat mass. Increased levels of bilirubin were moderately correlated with decreasing fat mass. Conclusions: In this small sample size, there are trends demonstrating ways to increase bilirubin through supplementation and that increasing bilirubin promotes decreases in body fat mass.

Digital Object Identifier (DOI)