Friday, April 11, 2014

Toxic Cinnamon? By Jerry Brainum

Next to black pepper, cinnamon is the most common spice used today. Cinnamon is derived from the bark of small evergreen trees grown in South and Southeast Asia, especially Sri Lanka. However, there are different kinds of cinnamon, and this can have an impact on health. For example, what's called true cinnamon, also known as Ceylon cinnamon comes mostly from Sri Lanka. The other predominant types include various forms of cassia, which includes Indonesian Cassia, Vietnamese Cassia, and Chinese Cassia. These look and smell like cinnamon, but they aren't true cinnamon, and this is where the health effects enter the picture.
    Cinnamon has a long history of use, dating back the Biblical times. It's mentioned in the Bible several times. Then, as now, it was primarily used as a spice for flavoring purposes.More recently, cinnamon has been suggested as a natural way to support healthy blood glucose levels. This, if true, could have a major significant impact on health, since the incidence of diseases related to poor glucose control, including insulin resistance, or "pre-diabetes," and type-2 diabetes, are are the rise worldwide. Type-2 diabetes was formerly called "adult-onset diabetes" to distinguish it from type-1 diabetes, which is caused by a destruction of the cells in the pancreas that produce insulin. The adult-onset form usually does not involve destruction of the pancreatic cells that produce insulin, but rather features a resistance of cells to insulin activity. The usual treatment involves a combination of oral drugs and exercise, or if the disease progresses, use of insulin itself to overcome the cellular resistance to the hormone. Type-2 diabetes is no longer referred to as "adult onset diabetes,"since it shows up in children as young as 12. The reasons for this are multifactorial, but relate mostly to a combination of lack of sufficient physical activity and excess body fat.
    Those who suffer from insulin resistance, which is characterized by elevated resting glucose levels, are often able to prevent the progression to full-blown diabetes if they lose excess body fat through a combination of exercise and diet. Low carbohydrate diets are particularly effective in this regard, since they tend to significantly reduce elevated resting insulin levels, as well as lower elevated blood glucose levels. Several natural supplements are also suggested as a safe way to help control elevated insulin and glucose levels. These include the trace mineral, chromium. Chromium is thought to work through boosting the effectiveness of insulin. It does this by modifying the cellular receptors for insulin, more or less providing a tighter bond of insulin to its cellular receptor. However, more recent studies have found that an excess of chromium produces the paradoxical effect of increasing insulin resistance. Even worse, the most recently published study found that chromium exerted little or no effect on elevated blood glucose levels. That, however, is just one study, and it would not be wise to cease consuming any chromium based on the findings of a single study.
    There are various other natural substances often suggested to control blood glucose levels, such as soluble fiber, which delays the absorption of simple carbohydrates, and thus lowers the insulin release effect. But among the various natural supplements touted to control glucose levels and possibly help to prevent the development of diabetes, cinnamon is the most often mentioned supplement. The research to prove this effect of cinnamon, however, is contradictory at best. One study published in 2003 provided 60 diabetic patients of both sexes with doses of 1, 3, or 6 grams of cinnamon powder. The treatment duration was 40 days, the results showed that cinnamon decreased fasting blood glucose levels, as well as lowering elevated blood lipid levels. Another study from 2006 featured 65 diabetic patients  who ingested 3 grams of a water extract of cinnamon for four months. The results of this study showed that while cinnamon did lower fasting blood glucose levels, it didn't affect blood lipid levels, nor did it affect hemoglobin A1C,a measure of long-term glucose usage in the body. Two other studies published the same year, found no effect of  cinnamon on blood glucose or other measures. Two studies published in 2007 likewise also found no effects of cinnamon when provided at a dose of one gram a day. Another study published the same year found that 6 grams of cinnamon delayed gastric emptying following a meal, which delayed the entrance of glucose into the blood. A Cochran review (which accessed previous studies) found that "cinnamon produces no more effects than a placebo." In other words, the review suggested that cinnamon was worthless in terms of glucose control.
    But that's not the biggest problem with cinnamon. It turns out that all of the commercial cinnamon on the market doesn't contain true or Ceylon cinnamon, but rather contains a variety of the cassia form. The problem here lies in a natural constituent of the cassia, but not Ceylon cinnamon, namely coumarin. The fact is that 90 percent of commerical cinnamon used in spices and supplements is the Indonesian cassia form, and in some cases, the Chinese cassia. Both of these forms contain significant amounts of coumarin. Why is that a problem?
    Coumarins can cause severe liver problems in animals, less so in humans. Some humans show liver abnormalities after consuming it, while others don't for unknown reasons. It is also a possible carcinogen, linked to causing tumors in animal studies. Coumarin also serves as a precursor for the production of the drug, Coumadin, trade name, Warfarin. Warfarin is a vitamin K antagonist that helps to prevent blood clots. It's often prescribed to treat people with atrial fibrillation, a defect of heart conduction that is a risk factor for strokes. The hope is that providing these people with Warfarin will lower stroke risk by preventing clot formation, which is often the cause of the strokes. Warfarin is also commonly used to kill rats.
   A recent study analyzed the levels of coumarin in both commercial cinnamon supplements, and cinnamon used for flavoring, spices, and so on. It found levels of coumarin that exceed the amount allowed by various health organizations to exist naturally in  food. True or Ceylon cinnamon was found to contain only trace amounts of coumarin. But all the cassia versions contained far more, and in some causes, possibly toxic levels of coumarin.
   The obvious solution to this problem would be to use only Ceylon cinnamon. The problem with this is that Ceylon cinnamon is virtually non-existent in the United States, where only the cassia forms are used. Another option is to use only special water-soluble cinnamon extract supplements, which are sold under various names. These supplements do not contain any coumarin, but they do contain the polyphenol substances thought to account for the beneficial effects of cinnamon. From an anecdotal point of view, I've tried both forms of cinnamon supplement, although the ones that I used were likely the cassia versions. Neither form, either the usual cinnamon or the far higher priced water-soluble form, did anything at all to control my blood glucose levels. Since I was insulin resistant at the time I used the supplements, I was a good test subject. I used the suggested doses, and regularly checked my resting blood glucose level, but found no changes whatsoever with use of either form of cinnamon. Am I saying that cinnamon is useless? Not at all. I think cinnamon tastes great, and I love it as a flavoring agent. But for treating insulin resistance and diabetes, well, let's just say I'm highly skeptical about that.


Wang, YH, et al. Cassia cinnamon as a source of coumarin in cinnamon-flavored food and food supplements in the United States.J Agric Food Chemistry 2013: in press.

©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

Please consider joining this blog by clicking on the blue "join this site" button to the right of this blog. This will ensure that new blogs continue to be published. It costs nothing, and takes only a few seconds. Thank you.

See Jerry's book at

Coming Soon: The return of Applied Metabolics Newsletter, the best source of information (ad free) for nutrition, exercise science, longevity research, women's health, and tales from the golden age of bodybuilding.