For a spice that has a history going back over 4,000 years, you would think that there wouldn’t be much controversy or confusion. Au contraire. The benefits and risks of cinnamon are making headlines these days like never before.
Just in the last week NPR ran two seemingly contradictory cinnamon stories:
The Straight & Skinny on Cinnamon
Part of the confusion surrounding cinnamon involves what is and is not “true” cinnamon. Cinnamomum zeylanicum, also known as Cinnamomum verum, is native to Ceylon (Sri Lanka). China and Southeast Asia are the home of Cinnamomum cassia, a related species that has an equally long history. Ancient Egyptians included both forms of cinnamon in their embalming formula for mummifying pharaohs because of the spices’ lovely aroma and preserving powers. The Bible refers to both cinnamon and cassia, which were used for aroma and flavor. Both types are derived from the bark of trees.
In modern times these two species are used interchangeably to flavor both sweet and savory dishes. What you find on the spice shelf in the supermarket is usually cassia cinnamon, because it is more readily available and cheaper than Ceylon cinnamon. The flavors are subtly different.
The more critical issue is whether they have the same medicinal properties and safety profile. Most of the research showing that cinnamon can lower blood sugar has utilized cassia cinnamon. The extracts that are sold in health food stores are also primarily derived from cassia cinnamon. But here’s the rub. Cassia cinnamon from China, Vietnam or Indonesia contains coumarin. This compound is a natural component of the cassia spice. It is found in varying amounts in different brands. When consumed at high levels, coumarin can cause liver damage in susceptible people. That is why Danish regulators are cracking down on a beloved treat we know as cinnamon swirls (kanelsnegle in Danish).
Five years ago the European Union passed strict limitations on the amount of coumarin allowed in food. German bakers were the first to feel the pinch. Authorities warned about coumarin levels in traditional cinnamon Christmas cookies (Zimtsterne). Regulators found some brands of cookies had coumarin levels 20 times higher than permitted by law. The German trade organization complained that the levels were too strict, since people only consumed their star-shaped cookies during the holidays. More recently, the Danish Baker’s Association has also complained:
“We must recognize that to get a cinnamon roll … to taste like cinnamon, we have to use more than the very small amounts allowed, or it’s the end of the cinnamon roll as we know it.”
While European bakers and regulators argue over coumarin levels in cinnamon-containing baked goods, the FDA seemingly shrugs its shoulders. European regulators are far more concerned about coumarin than their American counterparts. As far as we can tell, there are no U.S. limits on the amount of coumarin permitted in cinnamon-flavored baked goods in the United States. Analysis of such foods has found coumarin in detectable levels.
We are not terribly worried about an occasional cinnamon roll or cookie. What does concern us, however, is the growing trend for people who are diagnosed with type 2 diabetes or prediabetes to regularly consume cassia cinnamon on their oatmeal or toast in order to lower blood sugar levels. A teaspoon of cassia cinnamon daily could pose serious risks.
You might assume that is not a likely problem for most people. Not so fast. A meta-analysis of clinical trials in the Journal of Medicinal Food (Sept., 2011) revealed that “cinnamon extract and/or cinnamon improves FBG [fasting blood glucose] in people with type 2 diabetes or prediabetes.”
People love that sort of good news. It was reinforced more recently in the Annals of Family Medicine (Sept.-Oct., 2013). The authors concluded that, “Based on currently available literature, cinnamon may have a beneficial effect on fasting plasma glucose, LDL-C, HDL-C, and triglyceride levels in patients with type 2 diabetes.”
The Bad News About Cinnamon
Such studies create appealing headlines. People are told that cinnamon will not only lower blood sugar levels but also reduce bad LDL cholesterol and triglycerides and raise good HDL cholesterol. That might encourage some people to start consuming high doses of inexpensive cinnamon from their grocery shelves. One diabetes educator who was interviewed on NPR was quoted as saying cinnamon “is inexpensive,” “and it tastes good.”
That really worries us because regular consumption of inexpensive cassia cinnamon could lead to liver damage. Coumarin may also interact with other drugs including aspirin, NSAIDs (ibuprofen, naproxen, etc) and other anticoagulants such as warfarin (Coumadin), to name a few potential complications.
Over the years we have heard from many people that cinnamon helps control their blood glucose. Here are some stories from visitors to this website.
“I have been using Saigon cinnamon for about 2 months as a supplement to my diet and medication. I put it in coffee, cereal, or oatmeal (at least once daily in the morning).
“I have found that a sprinkle of cinnamon daily keeps my blood sugar from spiking. I still must maintain a diet of low carbs and no sugar, but my glucose remains at fairly constant levels (between 70 and 140) whereas without cinnamon it would spike sometimes as high as 230 for no apparent reason. Also, my A1C has dropped to 6.1 from the low 8s during this time.” Jim
“I sprinkle a little cinnamon on my oatmeal in the AM for my psoriatic arthritis. Sometimes I even add it to my plain low fat yogurt as well.” Kathleen
“Ooh Boy! I’m starting to worry. I’ve been taking an overdose of cinnamon for the better part of a month 2 heaping tablespoons per day. Now I have pains in the kidney area, just slightly. Have I damaged my liver? If so does it recover with cessation of the cinnamon?” A.P.
We advised A.P. to stop consuming cassia cinnamon. Hopefully her liver will recover, if in fact it was harmed.
The Good News About Cinnamon
True cinnamon or Ceylon cinnamon appears to have substantially lower levels of coumarin. Although it costs more, it does have a nice flavor and should be safer than cassia cinnamon. Here is a question we received about the effectiveness of Ceylon cinnamon:
“I understand that Saigon cassia cinnamon contains coumarin which can be toxic and has been linked to liver damage in some people. Aren’t diet and exercise are safer options for controlling blood sugar? And the Ceylon cinnamon is safer, but I can’t locate scientific evidence showing that it reduces blood sugar readings.”
PEOPLE’S PHARMACY RESPONSE:
For a long time, there weren’t any studies showing that Ceylon cinnamon was helpful. But that has been changing:
http://www.ncbi.nlm.nih.gov/pubmed/22518078 (This is a rat study)
http://www.ncbi.nlm.nih.gov/pubmed/23297571 (This one in mice, but the cinnamaldehyde compound used is present in Ceylon cinnamon)
“My question is similar to the one above; is cassia cinnamon the only type known to aid blood sugar control?” John
PEOPLES’S PHARMACY RESPONSE to John: At one time we would have said yes without hesitation. However, as more research accumulates, this answer has become less clear. Some studies indicate that Cinnamomum zeylanicum (Ceylon cinnamon) is also effective:
The Cinnamon Solution
“In 2007, I read on the People’s Pharmacy website that we could pour boiling water on the cassia cinnamon using a paper coffee filter as a way of extracting the coumarin. Per that article, ‘The active compound in cinnamon is water soluble but coumarin is not, so you get the benefit without the worry.'” Grace
Grace got it right. The active ingredient in cinnamon that helps lower blood sugar is water soluble. Using the technique she describes above can be helpful. Some people have complained, though, that it is too much trouble, or that putting cinnamon in the coffee filter creates a terrible mess or that they just plain do not like the taste of cinnamon in their coffee. There is another solution.
Health food stores now sell cinnamon extracts that have been purified so that there is no coumarin. One such brand of water-soluble cinnamon extract is Cinnulin PF. A visitor to this site offered the following:
“I became ‘pre-diabetic’ after being prescribed masses of prednisone for many months. I had allergic reactions to generic metformin [went into convulsions with first dose] and started researching cinnamon and other supplements. I found an interesting fact about the cinnamon: If taken in the high volumes necessary to help with the glucose insensitivity, a secondary ‘chemical’ in the cinnamon can cause harm to the liver and kidneys.
“This property, however is NOT water soluble while the beneficial components ARE; so I then found Cinnulin PF and found that this preparation extracted by a water process contains none of the problem component and all of the benefits. I began using Cinnulin PF [along with other foods] and no longer am ‘pre-diabetic’.” L.D.
If you would like to learn more about the pros and cons of cinnamon as well as other foods for good health, we recommend our book, Favorite Foods from The People’s Pharmacy: Mother Nature’s Medicine. You will get the straight and skinny on almonds, beets, blueberries, cherries, ginger, grape juice, green tea, hot peppers, mustard and pomegranates to name just a few of our favorite foods. Always remember, though, that too much of a good thing, even an otherwise healthy food, can sometimes pose problems. That is the lesson of cinnamon.