A Preliminary Analysis of the Influence of Elderberry Juice Consumption on Thyroid Metabolism in Mice and Humans Fed High-Fat Diets.

BACKGROUND/OBJECTIVES: Elderberry juice (EBJ) consumption prevents weight gain in mice fed a high-fat diet and increases fat oxidation in response to a meal challenge in overweight humans. Thyroid hormones influence metabolism and substrate oxidation, and the impact of EBJ consumption on thyroid homeostasis remains unexplored. Thus, the primary objective of this analysis was to investigate whether elderberry consumption in mice and humans affects serum thyroid biomarkers. METHODS: Serum samples from a previous trial incorporating an EBJ intervention were analyzed for thyroxine (T4), thyroid stimulating hormone (TSH), and thyroglobulin (Tg). The samples are from a meal-tolerance test in 18 humans who followed a 7-day diet-controlled crossover design. Samples from 33 male mice were collected after 13 weeks following a high-fat diet with or without EBJ powder, and with or without free wheel running. RESULTS: Short-term EBJ consumption in humans resulted in significant increases in T4 (PL: 42.3 ± 3.2 vs. EBJ: 49.3 ± 4.1 ng/mL, p < 0.05), and TSH (PL: 0.094 ± 0.012 vs. EBJ: 0.104 ± 0.011 ng/mL, p < 0.05), with no change in Tg (p > 0.05). Whereas supplementation with EBJ powder in rodents resulted in a non-significant reduction in T4 (p = 0.07). CONCLUSIONS: These findings suggest that elderberry juice consumption may influence thyroid metabolism, contributing to the observed metabolic benefits, such as improved fat oxidation, body composition, and protection against high-fat diet-induced weight gain. The increased T4 and TSH in humans align with enhanced metabolic rate, while the reduction in T4 in rodents indicates potential long-term adaptations requiring further exploration.