Introduction
Obesity in the United States continues to worsen, with the number of states with adult obesity rates at or above 35% doubling since 2018. The annual medical costs of obesity in the United States in 2019 were estimated at USD 173 billion. The study aimed to determine the effect of 100% elderberry juice on measures of indirect calorimetry (IC) and insulin sensitivity/glucose tolerance in a placebo-controlled, randomized, crossover pilot study.
Methods
Overweight and obese adults were randomized to a 5-week study which included 2 1-week periods of twice-daily elderberry juice (EBJ) or sugar-matched placebo consumption separated by a 3-week washout period. Following each 1-week test period, IC and insulin sensitivity/glucose tolerance was measured with a 3 h meal tolerance test (MTT).
Results
EBJ was well tolerated and compliance was 99.6%. Average carbohydrate oxidation was significantly higher during the MTT after 1-week EBJ consumption (3.38 vs. 2.88 g per interval, EBJ vs. placebo, p = 0.0113). Conversely, average fat oxidation was significantly higher during the MTT after 1-week placebo consumption (1.17 vs. 1.47 g per interval, EBJ vs. placebo, p = 0.0189). There was no difference in serum glucose or insulin response between treatments.
Discussion
The study suggests that 7-day feeding of 100% elderberry juice increases postprandial carbohydrate oxidation following a high-sugar MTT but does not affect serum glucose or insulin in a small sample of overweight or obese free-living participants. Elderberry juice is well tolerated, and follow-up work with more robust designs, controlling background diet with adequate statistical power, and testing similar glucoregulatory and calorimetry measures are warranted to confirm these potentially beneficial outcomes.
