Controlling Blood Glucose Levels

Chromium plays an important role in reducing sugar cravings and appetite and increasing lean body mass. In a double blind pilot study, two groups of volunteers (n=20) received 300 mcg/d of a NBC (as ChromeMate) or a placebo for three months.1 The treatment group’s mean fasting glucose level were significantly lowered, along with a reduction in mean triglyceride levels from 112 to 108 mg/dl. Mean Hb1Ac levels also lowered from 8.42 percent to 8.10 percent in the NBC group. Similarly, one-year supplementation of a combination of NBC (as ChromeMate), grape seed proanthocyanidins and zinc methionine significantly lowered SBP in normotensive rats, decreased hepatic, cardiac and renal lipid peroxidation and lowered HbA1c without showing signs of toxicity.2

Mulberry leaf has been shown to affect blood glucose levels. In a 2007 study, 10 subjects with type 2 diabetes and 10 healthy controls were given 1.0 g of mulberry leaf extract with 75 g of sucrose or a placebo.3 The mulberry extract significantly reduced the blood glucose increase at 15, 30 and 45 minutes after sucrose ingestion in both controls and subjects with diabetes, but increased blood glucose concentrations at the tail-end of the tolerance test. Area under the curve was not significantly altered by mulberry, but fluctuations in glucose concentrations were significantly reduced (P<0.01). Analysis indicated the extract caused malabsorption of 12 to 16 g of sucrose. The extract did not result in a significant increase in symptoms.

Researchers measured breath hydrogen and CO2 to investigate the ability of an extract of black, green and mulberry tea leaves to induce malabsorption of carbohydrate and triacylglycerol in healthy volunteers.4 Healthy adult volunteers randomly ingested test meals with a placebo beverage or as a preparation containing an extract of black (0.1 g), green (0.1 g) and mulberry (1.0 g) teas. One test meal contained 50 g of carbohydrate as white rice, 10 g of butter, and 0.2 of triolein, and the beverages contained 10 g of sucrose. The calorie content of the second meal consisted entirely of lipids (30 g olive oil and 0.2 g triolein). With the carbohydrate-containing meal, the tea extract resulted in a highly significant increase in breath-hydrogen concentrations, which indicated appreciable carbohydrate malabsorption. A comparison of hydrogen excretion after the carbohydrate-containing meal with that after the nonabsorbable disaccharide lactulose suggested the tea extract induced malabsorption of 25 percent of the carbohydrate. The tea extract did not cause triacylglycerol malabsorption or any significant increase in symptoms.

Along the same lines, researchers in 2008 investigated the effects of acute ingestion of a green tea extract (GTE) on glucose tolerance and fat oxidation during moderate-intensity exercise in humans.5 Two studies were performed, both with a counter-balanced crossover design. In study A, 12 healthy men performed a 30-minute cycling exercise at 60 percent of maximal oxygen consumption (VO2max) before and after supplementation. In study B, 11 healthy men took an oral-glucose-tolerance test before and after supplementation. In the 24-hour period before the experimental trials, participants ingested three capsules containing either GTE or a corn-flour placebo. Average fat oxidation rates were 17 percent higher after GTE-ingestion than after placebo-ingestion (P<0.05). The contribution of fat oxidation to total energy expenditure was also significantly higher after GTE supplementation. The insulin area under the curve decreased in both the GTE and placebo trials (P<0.01), and there was a concomitant increase of 13 percent in insulin sensitivity. A separate study looked at the anti-diabetic effects of the green tea catechin, epigallocatechin gallate (EGCG), in rodent models of type 2 diabetes mellitus and H4IIE rat hepatoma cells.6 EGCG beneficially modified glucose and lipid metabolism in H4IIE cells and enhanced glucose tolerance in diabetic rodents.

Toyo Bio-Pharma created a sweet potato leaf powder, Toyo-KanSho™, derived from the leaves and stems of Ipomoea batatas. According to literature from Toyo, the powder helps maintain healthy blood glucose levels, healthy blood pressure and promotes liver health.

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References for "Controlling Glucose Levels"

1. Messina M et al. “Skeletal benefits of soy isoflavones: a review of the clinical trial and epidemiologic data.” Curr Opin Clin Nutr Metab Care. 2004; 7:649-58.

2. Lethaby AE et al. “Phytoestrogens for vasomotor menopausal symptoms.” Cochrane Database Syst Rev. 2007 Oct;4:CD001395.

3. Krebs EE et al. “Phytoestrogens for treatment of menopausal symptoms: a systematic review.” Obstet Gynecol. 2004 Oct;104(4):824-36.

4. Williamson-Hughes PS et al. “Isoflavone supplements containing predominantly genistein reduce hot flash symptoms: a critical review of published studies” Menopause. 2006;13(5).

5. Baber RJ et al. “Randomized placebo-controlled trial of an isoflavone supplement and menopausal symptoms in women.” Climacteric.1999;2:85-92.

6. Knight DC et al.”The effect of Promensil, an isoflavone extract, on menopausal symptoms.” Climacteric. 1999;2:79-84.