Eun-Soo Jung

Reduction of blood lipid parameters by a 12-wk supplementation of aged black garlic: A randomized controlled trial

OBJECTIVE The cholesterol-lowering effects of garlic as part of a healthy diet remain controversial. The aim of this study was to investigate whether supplementation with aged black garlic (ABG) could improve blood lipid profiles in patients with mild hypercholesterolemia. METHODS We conducted a double-blind, randomized placebo-controlled trial. Sixty participants were randomly assigned to receive either ABG or placebo twice daily (total 6 g/d) before consumption of a meal every morning and evening for 12 wk. During the study, two participants dropped out of the ABG group, and three participants dropped out of the placebo group. Thus, the effects of AGB on fasting blood levels of lipids were evaluated in 28 participants and compared with the placebo group (n = 27). RESULTS Among lipid components, no significant differences in triglycerides, low-density lipoprotein cholesterol, total cholesterol, or free fatty acid levels were observed between the two groups. However, ABG increased high-density lipoprotein cholesterol levels compared with the placebo group at the end of the study. Moreover, a significant decrease in the levels of alipoprotein B and a significant increase in the ratio of low-density lipoprotein cholesterol/alipoprotein B were observed in the ABG group. No adverse effects were reported in any of the patients. CONCLUSION ABG supplementation reduced atherogenic markers and thus may have a cardioprotective effect beyond the gold standard medication in patients with mild hypercholesterolemia.

Improved cognitive performance following supplementation with a mixed-grain diet in high school students: a randomized controlled trial.

OBJECTIVE Adolescence is a stage of rapid growth, when rich nutritional supplementation is important. Maintaining optimal cognitive functioning is critical in high school students, who are under considerable academic pressure. The objectives of this study were to identify the effects of a 9-wk randomly assigned diet of mixed grains versus a regular diet on cognitive performance and on levels of plasma brain-derived neurotrophic factor (BDNF) and S100B, a calcium-binding protein produced by astroglial cells, in healthy high school students (grades 10 and 11). METHODS In this 9-wk, single-blind, controlled study, subjects were randomly allocated to either a mixed-grain or a regular diet. Cognitive assessments and measurements of plasma BDNF and S100B levels were performed at baseline and after the 9-wk intake of a mixed-grain or regular diet. Computerized neuropsychological tests and self-rating scales were used for the cognitive assessments. RESULTS Significant improvements in some neuropsychological tests were found after 9 wk in both the mixed-grain and the regular-diet groups, but the changes from baseline between the two groups were not significantly different. Significant impairments on the AX-continuous performance test were observed at the endpoint in the regular-diet group, and the changes from baseline between the two groups were also significantly different for this test. A significant difference in changes in BDNF levels was observed between the two groups. CONCLUSIONS These results suggest that intake of mixed grains for 9 wk is beneficial for cognitive performance and plasma BDNF levels in high school students. These beneficial effects seem to be related to the prevention of cognitive deterioration in a mental-fatigue test with the mixed-grain diet, rather than cognitive enhancement per se.

Mixed grain containing giant embryonic brown rice improves postprandial glycaemic response in healthy subjects

Aim Mixed grain, which contributes to lowered glycaemic responses, has been shown to be effective in dietary management of patients with impaired glucose tolerance or diabetes. Methods The present study determined the postprandial blood glucose response of 20 healthy volunteers to mixed grains containing giant embryonic rice (MG-GER) or giant embryonic brown rice (MG-GEBR) compared with white rice (WR) in a randomised crossover design. Plasma glucose and serum insulin at 0, 15, 30, 45, 60, 90, 120, 150 and 180 minutes were measured, and glycaemic index (GI) and incremental area under the curve (iAUC) were calculated. Results The GIs for WR, MG-GER and MG-GEBR were 86.75 ± 5.78, 76.09 ± 7.01 and 69.33 ± 6.54, respectively. The 120-minute iAUCs after administration of MG-GER or MG-GEBR were significantly lower than that of WR. In addition, the MG-GEBR diet group had a significantly lower C-peptide concentration at the 120-minute time point when compared to the WR group. Conclusions These results suggest that consumption of MG-GER or MG-GEBR instead of WR is more effective to reduce postprandial glucose levels without increasing insulin secretion.

Mulberry leaf extract displays antidiabetic activity in db/db mice via Akt and AMP-activated protein kinase phosphorylation

Background Augmenting glucose utilization in skeletal muscle via the phosphatidylinositol-3 kinase (PI3 kinase)/protein kinase B (Akt) pathway or the adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway is necessary to regulate hyperglycemia in patients with type 2 diabetes mellitus. Objective We investigated the effect of mulberry leaf extract (MLE) on glucose uptake in skeletal muscle cells and explored its in vivo antidiabetic potential. Design Male db/db mice were treated with either MLE (50 mg/kg, 100 mg/kg, and 250 mg/kg) or metformin (100 mg/kg) for 8 weeks. Results MLE treatment stimulated glucose uptake, driven by enhanced translocation of glucose transporter 4 to cell membranes in L6 myotubes. These effects of MLE were synergistic with those of insulin and were abolished in the presence of PI3K inhibitor or AMPK inhibitor. In db/db mice, supplementation with MLE decreased fasting blood glucose and insulin levels and enhanced insulin sensitivity, with increases of p-Akt and p-AMPK in skeletal muscle. Moreover, MLE improved blood lipid parameters and attenuated hepatic steatosis in diabetic db/db mice. Discussion These findings suggest that MLE exerts antidiabetic activity through stimulating glucose disposal in skeletal muscle cells via the PI3K/Akt and AMPK pathways. Conclusions MLE can potentially improve hyperglycemia and hepatic steatosis in patients with type 2 diabetes.