Researchers have found that American ginseng (Panax quinquefolius) can help lower blood sugar levels in people both with and without type 2 diabetes. When taken about 40 minutes before a meal, both diabetics' and non-diabetics' blood sugar levels go down. When taken with a meal, blood sugar levels drop only for people with diabetes. Ginseng may lower blood sugar by slowing digestion, increasing sugar uptake in cells or by increasing insulin levels -- researchers aren't sure of the exact mechanism. If you take ginseng -- for whatever reason -- be careful to watch for any hypoglycemic (low blood sugar) reactions.

From Hopeheart.org