One meta-analysis (pooling data from several studies) demonstrated a 9 mg/dl (0.
48-0.49 mmol/l in si units) drop in fasting blood glucose
with cinnamon extract. I do not know how much cinnamon was used in the study; perhaps someone else can comment? (davis pa; yokoyama w, "cinnamon intake lowers fasting blood glucose: meta-analysis."j med food. 2011; 14(9):884-9).