To determine the effect of polysaccharides from American ginseng root on postprandial glycemia in healthy individuals.

Glycemia-lowering effects of American ginseng root have been repeatedly observed in healthy individuals and in type 2 diabetes. It is unclear which components trigger these effects. Pre-clinical evidence suggests that, aside from ginseng saponins, ginseng polysaccharides may reduce glycemia. This assumption has not been investigated so far in humans.

We therefore undertook a double-blind randomized controlled clinical trial to determine the effect of American ginseng root polysaccharides, at escalating doses, on postprandial glycemia, in comparison to the American ginseng root and control in healthy individuals. We hypothesized that polysaccharides will reduce glycemia comparably to a dose of ginseng root that contains polysaccharides at an equivalent amount to the average polysaccharide dose. We therefore tested polysaccharide doses equivalent to 9, 12 and 15 g of rot, 12 go of ginseng root and a wheat bran control. Each subject received each treatment in random sequence, after a 12-hour overnight fast and 40 minutes prior to a 25-g oral glucose tolerance test. Capillary blood samples were collected at baseline, prior to glucose ingestion and at 15, 30, 45, 60, 90, 120 minutes after the start of glucose intake. Capillary blood glucose was measured.

Inclusion Criteria:

• 16-65 years old
• normal renal and hepatic function
• fasting plasma glucose: 4-6 mmol/l
• clinically euthyroid
• normotensive

Exclusion Criteria:

• pregnant
• taking herbs, supplements or medication that affect glycemia
• major illnesses/ disease
• heavy alcohol use (> 3 drinks/ day)
• heavy smoking (> 10 cigarettes/ day)