Objective: To determine the efficacy of a dietary supplement ingredient containing proprietary extracts of Magnolia officinalis and Phellodendron amurense in helping overweight, otherwise healthy, premenopausal female adults, who typically eat more in stressful situations manage their body weight.
Design: Randomized, double-blind, placebo-controlled clinical study. Setting Miami Research Associates, a clinical research organization consisting of 32 board-certified physicians, Miami, Fla.
Subjects: Healthy, overweight (BMI 25 to 34.9), premenopausal female adults, between the ages of 20 and 50 years, who typically eat more in response to stressful situations and scored above the national mean for women on self-reported anxiety.
Interventions: Two-hundred-fifty-mg capsules or identical placebo capsules 3 times a day for 6 weeks.
Main outcome measures: Salivary cortisol levels, weight change, psychological measures of stress and anxiety.
Results: Twenty-eight subjects completed the study. Extracts of M officinalis and P amurense were well tolerated. There was a significant weight gain during the study for the placebo group (P < ,01), but no significant weight gain for the group receiving extracts of M officinalis and P amurense (P < .89). Paired t-tests comparing baseline to post-treatment weight showed an average gain of 1.5 kg in the placebo group and no change in the treatment group (P = .89). When groups were divided into gainers (ie, participants who gained at least 1 kg or more) and maintainers or losers, 75% of the control group were gainers versus 37% of the treatment group (P < .04). There was a nonsignificant trend for lowered average cortisol in the treatment group at the end of the study (group X time interaction, F = 1.1, P < .15). This difference was due to a treatment effect on evening cortisol. There was a marginally significant group X time interaction (P = .06), showing the treatment group tended to have lower levels of cortisol in the evening, whereas the control group tended to have higher levels of cortisol in the evening. Bedtime cortisol levels decreased in the treatment group and increased in the placebo group. Participants in both the treatment and placebo groups had improved scores on a number of psychological measures during the study. There was a correlation between perceived stress and weight change.
Conclusion: The results of this pilot clinical study indicate that obese subjects who eat in response to stress may benefit from taking a dietary supplement ingredient containing proprietary extracts of M officinalis and P amurense. The mechanism of action appears to be through reduction of cortisol levels and possibly perceived stress, thereby helping participants maintain body weight. The sample size was small, however, and there was higher attrition in the control group than in the treatment group.