Tuesday, February 9, 2010

Cinnamon and Blood Glucose

The other day I was at Sam's Club, pushing my cart past the supplement section on the way to the meat counter. As I glanced at the shelves, I noticed something new. There was a bottle containing 500 mg capsules of cinnamon (specifically, ground Cinnamomum cassia bark). On the one hand, I had heard that cinnamon was able to improve blood glucose levels, but I hadn't read any of the papers. On the other hand, my fasting blood glucose levels had been in the 100 mg/dl range for a while, even though I eat less than 10 grams of carbs per day. I had been taking chromium supplements, but they didn't seem to have much of an effect. Since the cinnamon capsules weren't particularly expensive, I decided to take a chance and I bought them.

When I got home, I pulled up some of the scientific papers on cinnamon and saw that a reasonable dose would be about 1.5 grams per day. I took a capsule at breakfast, lunch and bedtime and the next morning my blood glucose was 95. To my amazement, the readings continued near that value throughout the week. I told a prediabetic friend about this, and she decided to try it as well. She too noticed a drop of about 5-10 mg/dl in her blood glucose levels. Next, my husband told one of the people at work about my experience. She has type 2 diabetes and is taking both oral hypoglycemic agents and a bit of insulin. She tried the cinnamon capsules and her blood glucose levels fell by 50 mg/dl.

Alrighty then. I decided it was time to read the scientific papers and see if there was anything to these anecdotal experiences. This blogpost will summarize my findings, such as they are.

In 2003 a paper by Khan et al. appeared in Diabetes Care. It described a group of 60 people who had type 2 diabetes and were being treated with sulfonylurea drugs. They were divided into six groups, with the first three taking 1, 3 or 6 grams of cinnamon daily while the second three were given placebo capsules of 1, 3 or 6 grams of wheat flour. After 40 days of treatment, the placebo groups experienced no change in fasting serum glucose, but the three treatment groups experienced decreases of 25%, 18% and 29%. There did not appear to be a dose-response because all three levels of cinnamon intake produced similar results.

This result was not totally unexpected because cinnamon had been observed to have insulin-enhancing activity in laboratory studies. With that in mind, several groups performed prospective clinical trials with cinnamon in human beings. Five of these studies were reviewed by Baker et al. in 2008. They concluded that the use of cinnamon did not significantly alter hemoglobin A1c or fasting blood glucose in patients with type 1 or type 2 diabetes.

However, other studies showed that there was an improvement in blood glucose with cinnamon. Zeigenfuss et al. used an aqueous cinnamon extract to treat prediabetic subjects and saw no effect at six weeks, but at twelve weeks observed an 8.4% drop in fasting blood glucose. In 2007 Wang et al. studied women with polycystic ovary syndrome (PCOS), a hormone disorder associated with insulin resistance. After eight weeks of treatment with a cinnamon extract, these women experienced significant declines both in fasting blood glucose and in two measures of insulin resistance. In 2009 Paul Crawford studied a heterogenous group of poorly controlled type 2 diabetics in a primary care setting. Their medications and dietary recommendations were left unchanged, but the treatment group received an add-on dose of 1 gram of cinnamon per day in an open-label study. After 90 days, the treatment group had significantly lowered its hemoglobin A1c from 8.47 to 7.64.

A 2008 lecture by Richard A. Anderson gives some insight into the possible mechanisms of cinnamon enhancement of insulin sensitivity. When insulin binds to its receptor, it starts a signaling cascade that begins with the autophosphorylation of the insulin receptor. In the presence of cinnamon extracts, this autophosphorylation is more robust. Not only that, cinnamon inhibits the dephosphorylation of the insulin receptor, which further enhances the signal. Cinnamon also increases the amount of insulin receptor proteins and of other proteins in the insulin signaling pathway. Cinnamon is not a substitute for insulin, but it does make insulin signaling more sensitive to the insulin that is present in the blood.

In summary, it appears that supplementation with cinnamon may provide a small but significant improvement in insulin sensitivity. It appears to have a greater influence in people with poorly controlled blood sugar, especially in those who are taking drugs that enhance insulin secretion by the pancreas. In people who are pre-diabetic, the glucose-lowering effect seems to be less. In fact, when cinnamon is given to normal subjects, it does not decrease their blood glucose, but instead reduces their postprandial serum insulin. Although the anecdotal experiences I related at the beginning would suggest that cinnamon has an immediate effect on blood glucose, from the scientific literature, it appears that it may take up to 12 weeks to exert its actions.

Even though cinnamon is found in practically every kitchen in the Western world, it is important to note that some people are allergic to cinnamon. If you decide to try cinnamon supplementation, be careful to look for rashes, inflammation of the mucous membranes or even trouble with breathing. Be sure to discontinue the cinnamon if any of these symptoms occur.

That said, it appears that supplementation with cinnamon may be helpful as part of a strategy to normalize blood glucose levels.


Aaron M Fraser said...

I am blaming you entirely for the ridiculous amount of cinnamon that will be going into my cooking the next few days.

Stargazey said...

That's great! (As long as it's not cinnamon rolls or rice pudding, LOL!)

anne h said...

I add it to coffee sometimes - probably mixes w caffeine to make a pro-drug!
That and vanilla!

sophia said...

Thanks for such a great blog. I've been reading about cinnamon for a while now. Given your knowledge, I was curious what your thoughts on these new studies and claims about Licorice Flavonoid Oil and its effect on fat storage: http://www.jstage.jst.go.jp/article/jhs/52/6/52_672/_article.


Stargazey said...

Sophia, I did a brief Google search on licorice flavonoid oil. The title of the article you referenced is "Licorice Flavonoid Oil Effects Body Weight Loss by Reduction of Body Fat Mass in Overweight Subjects." Except for a study that addressed the safety of licorice flavonoid oil, it's just about the only one out there.

I have a few quarrels with the title. Yes, most of the subjects could be called overweight, but their average BMI (body mass index) was about 26.5. A normal BMI is 25, which means that these people were only slightly overweight. Second, the treatment group did not lose weight. Over the 12-week course of treatment, they maintained their weight.

The odd part of the study was found in the placebo group, which received a single daily capsule containing 300 mg of medium chain triglycerides plus 33 mg of beeswax. For some reason, in healthy volunteers the placebo produced an average gain of 1.3 pounds in 12 weeks. The graphs are not completely clear, but it appears that when the control subjects took six capsules a day of the placebo in a four-week follow-on study, the placebo group gained a total of 2.2 pounds in 16 weeks. When the treatment group received six licorice flavonoid oil capsules per day for four weeks, they did not gain or lose any additional weight.

In short, the licorice flavonoid oil does not seem to have much effect on weight loss in mildly overweight people. On the other hand, be very careful of taking medium chain triglycerides plus beeswax. It will really pack on the pounds.

Stargazey said...

Just to be clear, I'm obviously kidding about avoiding medium chain triglycerides plus beeswax. But there was some important but unknown difference between the placebo and licorice flavonoid oil groups. Healthy, slightly-overweight people do not normally gain 2.2 pounds in sixteen weeks unless they are working at it. I am surprised the reviewers did not notice this and insist that the authors account for it in some way.

sophia said...


Thanks for such a quick response! You mean Licorice Flavonoid Oil could be fattening!? But I swear I read these studies that claimed it actually reduced body fat in the study participants. This is why I was so impressed. Here are two more sites that have different results:


Maybe they got it wrong, Darn! But I think you are right that it is odd they didn't address the placebo group. They didn't say that they were all eating more than usual and one group gained and one group didn't or something like that. THANKS AGAIN.

Stargazey said...

Thanks for the additional references, Sophia. They both appear to be referring to this article which is by the same set of authors. I only have a link to the abstract, and would want to see the entire article before I could be sure that they didn't have problems with their data analysis.

If licorice flavonoid oil does decrease body fat, no doubt other investigators will see it as a research opportunity and provide additional data for evaluation. If you're interested in licorice flavonoid oil as a supplement, it would probably be safe to try it and see if it has any effect on your body composition. However, I wouldn't necessarily expect dramatic results.

sophia said...


Thanks for being so generous with your time and knowledge.


Joe said...

Stargazey, very interesting! I'm obese, and am looking for ways of decreasing insulin. Cinnamon looks like it's worth a look.

I also wanted to thank you for taking the time to visit MariaSol's blog. Your comments are thoughtful, and caused me to rethink a grain-fed muscle meat diet.

In the future please be careful, as you nearly ruined my monitor! I was drinking some water when I came across:
"What was I thinking, OhYeahBabe? I forgot that if you eat no carbs and nothing but grain fed meat and water, Looney Tunes biochemistry kicks in and you don’t need nutrients any more. Thanks for setting me straight!!"

and had to struggle to keep from spewing water all over my computer because I wanted to laugh so hard.

Thanks again.


Stargazey said...

Thanks, Joe! I'm spending more time over there than I should, I'm afraid!

Nigel Kinbrum said...

Has anyone tried taking Vitamin D3 to increase their insulin sensitivity? I'm taking 50iu/kg bodyweight/day (5,000iu/day at my weight) and it gave a big improvement to both my fasting glucose & OGTT results. See Vitamin D for more info'.

jacque k said...


Interesting post about cinnamon. I recall reading in Jenny's blog some months ago that cinnamon had no affect on the bg of post-menopausal women. Did you find anything like that in your research?

Stargazey said...

Good point. Jenny's assessment of cinnamon supplementation supplementation can be found here. The article you are talking about can be found here.

If cinnamon does have an effect on insulin sensitivity, it is a small one and it may take a while to happen. In this case, the cinnamon was only used for six weeks. As you can see, at six weeks, the cinnamon group saw a small but nonsignificant decrease in their fasting blood glucose. It's impossible to know if the decrease would have been greater had the study been extended to twelve weeks. As for the HbA1c, those tests are normally performed three months apart. It is unclear why the investigators would have used this test as a measure of efficacy after only six weeks of treatment.

That said, it's entirely possible that supplementation with cinnamon is not worth the expense and the trouble. People who take cinnamon should monitor their fasting and postprandial glucose to see if the cinnamon is making a difference.

I note that at the end of her section on cinnamon, Jenny says, "If you have high blood pressure be sure to monitor your blood pressure as some people have found that large doses of cinnamon raise blood pressure."

It's always a good idea to be careful with supplements, so if you have high blood pressure, please check that as well as your blood sugars when you are deciding whether or not to supplement with cinnamon.

Drael64 said...

Hi there. I am low carb (60-80grams per day). Have only been for three months. I used 1/4 teaspoon of tumeric (blood sugar lowering), and 2 heaped teaspoons of cinnomin, in a meal. And I am pretty sure this caused a blood sugar dip - spacey/dizziness, increased heart rate, difficulty thinking, anxiety. I dont have a blood sugar meter, but I think anyone with increased blood sugar, due to the body saving glucose for the brain with a high fat, low carb diet might want to be careful with blood sugar lowering herbs, spices and drugs. Just saying, I was eating my meal, and suddenly all those weird symptoms came over me. Oral dissolved glucose seems to have resolved it. Again, this could be some other effect of the combination of small amounts of tumeric and larger amounts of cinnamon, but I assure anyone reading I was fully relaxed and am not a hypocondriac. What I felt could indicate a risk using too large amounts of blood sugar lowering drugs when on a low carb diet...

John Newman said...

I can tell you without a doubt that taking cinnamon in capsule form brings down my blood sugar substantially. It is not uncommon to see a 50 point drop rather quickly. I am a 54 year old white male with Type 2 Diabetes. I take Metformin twice per day and a cholesterol reducer and 5mg Lisinopril. Cinnamon does the job I don't care what anybody says. I am living proof of that.

Mirjam B├╝ttner said...

Thanks for this interesting article! I read something about this before in "The Four Hour Body". Tim Ferris describes measuring his bloodsugar and seeing significant results with cinnamon (and also lemon juice before a meal to decrease the spike). Probably the amount of cinnamon matters as well. Weird how individual measurements show a quick response, although the scientific literature does not show this.