A dual investigation of the effect of dietary supplementation with licorice flavonoid oil on anthropometric and biochemical markers of health and adiposity

Abstract

BackgroundLicorice flavonoid oil (LFO) has been reported to minimize visceral adipose tissue gain in obese mice and to result in a decrease in body weight and body fat in humans; the effects of which may be more pronounced when administered in an overfed state.MethodsWe investigated the effects of LFO in two separate studies. Study 1 included a sample of overweight or grade I-II obese men and women (N = 22) who followed their usual dietary and physical activity programs. Study 2 included a sample of athletic men who followed their usual dietary and physical activity programs but consumed a daily supplemental meal (25% above daily energy requirements) in an attempt to induce a state of overfeeding. In both studies, subjects were randomly assigned (double-blind) to either LFO or a placebo for eight weeks, and anthropometric and multiple biochemical outcomes (e.g., markers of oxidative stress, markers of insulin sensitivity, blood lipids, etc.) were obtained before and following the intervention.ResultsNo differences of statistical significance were noted between LFO and placebo for any measured variable in Study 1 or Study 2. When investigating the percent change from baseline for data in Study 2, although not of statistical significance, subjects in the LFO condition experienced less overall fat gain, as well as attenuation in the elevation in selected blood lipids (e.g., cholesterol, LDL-C, and triglycerides).ConclusionThese combined data indicate little effect of LFO supplementation within a sample of overweight/obese men and women or athletic men, with the possible exception of attenuation in body fat gain and selected components of the blood lipid panel in response to an overfeeding condition.

Effects of dried licorice extract with low-calorie diet on lipid profile and atherogenic indices in overweight and obese subjects: A randomized controlled clinical trial

“…Some studies indicated suppressive effects of licorice on weight gain but others reported that licorice did not have any effective role on body weight. In line with our study, Bell et al [11] reported that Glavonoid TM , "a commercial licorice extract", did not change body weight in overweight, obese subjects and athletes. Also Hajiaghamohammadi et al [15] could not find any effect of aqueous licorice extract on weight and BMI of patients with non-alcoholic fatty liver disease.…”

“…Also, doses of 400 and 800 mg/kg/day of licorice extract in a study by Shalaby et al [20] decreased TC and TG levels with no changes in LDL, HDL and VLDL-c in male rats. On the contrary with the current study, Bell et al [11] reported that LFO had no effects on lipid profile in overweight/obese subjects and athlete men after 8 weeks. Differences in the dietary intake, basal lipid profile status, dose and type of licorice and duration of interventions might resulted in the contrary results.…”

“…Also, Tominaga et al [10] reported that licorice flavenoid oil (LFO) reduced LDL-levels after 8 weeks in overweight subjects. Whilst, Bell et al [11] trial did not find any effect of LFO on lipid profile in overweight/obese subjects and athlete men after 8 weeks.…”

Polyphenols and Their Role in Obesity Management: A Systematic Review of Randomized Clinical Trials

“…In their study on LFO, Bell et al . () noted a significant increase in weight only in the control group and suggested that LFO can be helpful in reducing weight gain in periods of overfeeding. Additionally, a study that did not meet the inclusion criteria for this systematic review showed that 1 month of pomegranate juice supplementation prevented an increase in weight, BMI, and body fat mass in obese participants (mean difference from baseline: −0.5 ± 2.3 kg, −0.2 ± 0.5 kg/m 2 , −1.4 ± 3%, respectively, p > 0.05) compared with the group administered the control juice (weight, BMI, and body fat mass increased by 1.1 ± 1.3 kg, 0.4 ± 0.5 kg/m 2 , 1.1 ± 1.1%, respectively, p < 0.05) (Gonzàlez‐Ortiz et al ., ).…”

Flavonoids and metabolic syndrome

“…However, other studies showed no effects of flavonoids on obesity parameters. For example, in overweight/obese subjects, the consumption of dark chocolate rich in catechin and epicatechin (1.0 g/day) for two weeks 20 or administration of a licorice flavonoid oil (300 mg/day) for eight weeks 21 did not modify body mass, composition, or waist circumference. In another study of obese subjects flavonol quercetin supplementation (500 and 1000 mg/day) for 12 weeks did not modify body mass and body composition 22 .…”