My own claim to expertise on the subject is, other than having been involved in designing a clinical trial to test the efficacy of cinnamon for diabetes and having written a few books on herbal medicine, I'm also a former formulator of some of the kinds of products you find on store shelves.
The good news about cinnamon for diabetes is, it sometimes actually works. The bad news about cinnamon for diabetes is, it doesn't always work for diabetes, and there's more than one kind of cinnamon.
The cinnamon that has been documented in published clinical research is Cinnamomum cassia. It's the blackish-grayish cinnamon at the far left of the photograph above. Despite what some "experts" say, this isn't the kind of cinnamon you sprinkle on your oatmeal or you get with cinnamon rolls, at least if you're getting the good stuff. That other kind of cinnamon is Cinnamomum cassia. is dark brown, whereas the milder Cinnamomum zeylanicum is more of a tan.
Cinnamomum cassia is a slightly bitter, not quite as aromatic variety of cinnamon used in South Asian cuisine. It's not the kind used in quality baked goods. It's the kind used in curry.
Cinnamomum cassia is a centuries-old Ayurvedic and Udani (Pakistani) remedy. And it's the herb that was used in the now-famous study conducted in Pakistan and monitored in the US.
This study of the use of 1, 3, or 6 grams (1 gram = 1,000 mg) of cinnamon every day for 40 days found that on average in a group of diabetics who did not have any other treatment:
Fasting glucose was lowered 18 to 29 per cent. For most diabetics, this would be something in the range of 30-50 mg/dl, or 1-2.5 mM.
LDL, or "bad," cholesterol was lowered 7 to 27 per cent.
Total cholesterol was lowered 12 to 26 per cent without any loss of the protective HDL cholesterol.
Fasting triglycerides were lowerd 23 to 30 per cent.
What's even better was, the benefits continued even after the clinical trial participants quit taking cinnamon. And more was not necessarily better. The optimum dose was 3,000 mg a day, not 6,000 mg.
So what's the catch?
The people who benefited most from taking cinnamon in this study (and in several others) were people who had type 2 diabetes and who didn't have access to any other medication. They weren't in severe distress from high blood sugars, but they probably did have sugars running 220 mg/dl (10+ mM). Cinnamon got sugars down to 140 mg/dl (7 mM) or so.
Cinnamon--and remember, it has to be the right kind of cinnamon--helps a whole lot of if you're just diagnosed and struggling to find some way to get your sugars down. No doctor is going to tell you it's enough, but the fact is, it can help.
If your goal is to get your morning blood sugar from 90 mg/dl to 85, cinnamon won't help you all that much.
What about the other kind of cinnamon? Well, basically, it's tasty. And there's nothing wrong with that. Just be sure the product you take for diabetes is labeled Cinnamomum cassia. It doesn't have to be an expensive extract. The cheaper capsules of pure cinnamon work just as well.
Frequently Asked Questions (Updated April 3, 2008):
Q. Wasn't there a Dutch study that found that cinnamon does not lower blood sugars?
A. There’s always a researcher out there trying to prove an herb doesn’t work, so a few years after the study I mention above, Dutch researchers tried using a low dose (1,500 mg a day) to treat type 2 diabetes in women.
The findings in the Dutch study?
Cinnamon lowered blood sugars.
Cinnamon lowered triglycerides.
Cinnamon lowered total cholesterol.
Cinnamon lowered LDL cholesterol.
Cinnamon raised HDL cholesterol.
But the Dutch researchers concluded cinnamon didn’t work because there were no significant differences between the control and treatment groups. They studied half as many patients, so the statistics were less likely to show significance.
Q. Wasn't there a study that found that cinnamon does help teens with diabetes?
A. Yes, but that's teens with type I diabetes. No one has studied the use of cinnamon in teens with type II.
Photo credit: www.aziatische-ingredienten.nl [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons