Good question! Cinnamon remains controversial. There is some evidence that taking cinnamon (either in supplemental forms or as the spice we’re all familiar with) can help improve glucose disposal, and it’s possible that may translate into better glycemic control, especially for diabetics. However, like so many other “natural remedies” the evidence is weak, and some studies have seen no improvement when subjects were given cinnamon.
Improvements in blood sugar have been reported in subjects with type 2 diabetes. Dosages range from 1-6 grams of cinnamon daily (in capsules) for 40-90 days (1,2). The improvements were small, but statistically significant. However, a study published in 2006 found that supplementing 1.5 grams of cinnamon daily for 12 weeks produced no effects on blood sugar in type 2 diabetics. In type 1 diabetics, cinnamon does not appear to have any effect (3).
But these studies were done on people with diabetes, what about in people who are not diabetic? A 2009 paper reported that healthy male volunteers did show increased glucose sensitivity after taking 3 grams of cinnamon per day in capsules. But as soon as the subjects stopped, the effect was gone in 2 days or less (4).
The bottom line: If you are type 2 diabetic, adding cinnamon to foods like oatmeal may give you a slight benefit in terms of glycemic control, but should not be used as replacement for prescribed medication or lifestyle modification. It’s not going to be nearly as helpful as, say, exercising or losing weight. If you are type 1 diabetic, the evidence doesn’t support much of an effect, and if you are healthy (non-diabetic), I don’t think there’s much to be gained. That said, if you like cinnamon, go ahead and use it to flavor your foods, especially if it helps you use less sugar, that’s a good thing no one disputes.
(1). Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. Crawford P. J Am Board Fam Med. 2009 Sep-Oct;22(5):507-12.
(2). Diabetes Care. 2003 Dec;26(12):3215-8. Cinnamon improves glucose and lipids of people with type 2 diabetes. Khan A, Safdar M, Ali Khan MM, Khattak KN, Anderson RA.
(3.) Diabetes Care. 2007 Apr;30(4):813-6. The effect of cinnamon on A1C among adolescents with type 1 diabetes. Altschuler JA, Casella SJ, MacKenzie TA, Curtis KM.
(4). Eur J Appl Physiol. 2009 Apr;105(6):969-76. Changes in glucose tolerance and insulin sensitivity following 2 weeks of daily cinnamon ingestion in healthy humans. Solomon TP, Blannin AK.