1. Introduction
Obesity, obesity, obese, Overweight, overweight
OBESITY, OBESITY, OBESE, RECRUITMENT, DISEASE, INSULIN SENSITIVITY, COMPLICATIONS
Obesity in the United States continues to worsen. Anthocyanin-rich fruits and vegetables provide a pragmatic dietary approach to slow its metabolic complications. Given American diet patterns, foods with high anthocyanin content could address dose-response challenges. The study objective was 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. 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). Treatment differences were tested with linear mixed modeling. A total of 22 prospective study volunteers (18 F/4 M) attended recruitment meetings, and 9 were analyzed for treatment differences. EBJ was well tolerated and compliance was 99.6%. A total of 6 IC measures (intervals) were created, which coincided with 10–20 min gaseous samplings in-between MTT blood samplings. Average CHO oxidation was significantly higher during the MTT after 1-week EBJ consumption (3.38 vs. 2.88 g per interval, EBJ vs. placebo, The 2022 estimates from the Centers for Disease Control and Prevention show that the number of states with adult obesity rates at or above 35% has doubled since 2018 [Commonly consumed berries are rich in polyphenols, notably flavonoids and anthocyanins [Despite less commercial attention compared to other conventional berry varieties, clinical research with elderberry interventions is warranted due to their high concentration of anthocyanins; because of the 5-fold higher density, EBJ provides 360 mg of anthocyanins with a 177 mL (6-ounce) serving [The objective of this pilot study was to test EBJ consumption for effects on substrate oxidation and insulin sensitivity in overweight or obese adults, who are otherwise healthy, utilizing an investigator-initiated, randomized, placebo-controlled, crossover design. The selected testing protocols were utilized in earlier reports that showed significant changes caused by berry interventions within short-term feeding designs. This pilot trial risks insufficient power to detect treatment differences due to a limited sample size, but the utility offered is the determination of potential directionality of treatment differences as a basis for power calculations for follow-up research. Despite this study’s limited power, we report significant effects of elderberry consumption on substrate oxidation. Moreover, as EBJ is an uncommon yet dense source of anthocyanins, an added utility of this pilot study is to determine its consumer acceptability.