Background: Lycium barbarum (L. barbarum), a traditional Asian medicinal therapy for diabetes and other conditions, has been shown to increase metabolic rate and to reduce body-weight gains in rodent models, as well as to produce clinical improvements in general feelings of well-being including energy level.
Objective: To investigate the impact of L. barbarum consumption on (1) caloric expenditure and (2) changes in morphometric parameters (waist circumference) in healthy human adults.
Method: Two separate randomized, double-blind, placebo-controlled, small clinical studies were conducted using a standardized L. barbarum fruit juice, GoChi, and assessing its effects on (1) resting metabolic rate (RMR) and postprandial energy expenditure (PPEE) as measured by indirect calorimetry after single-bolus intake of 3 doses of L. barbarum (30, 60, and 120 ml) and placebo; and (2) waist circumference and other morphometric changes in a 14-day intervention trial (120-ml daily intake) in the subjects (age = 34 years, body mass index = 29 kg/m(2)).
Results: (1) A single bolus of L. barbarum intake increased PPEE 1 through 4 hours postintake over the baseline level in a dose-dependent manner and was significantly higher than the placebo group by 10% at 1 hour postintake of 120 ml (p < 0.05). (2) In a 14-day intervention trial, L. barbarum was found to significantly decrease waist circumference by 5.5 ± 0.8 cm (n = 15) compared with the preintervention measurements and placebo group at postintervention day 15 (p < 0.01). By contrast, the changes in the placebo group (n = 14) from preinterventions was 0.9 ± 0.8 cm, which was not statistically significant.
Conclusions: These results show that L. barbarum consumption increases metabolic rate and reduces the waist circumference, relative to placebo treated control subjects.