Cinnamon for diabetes – myth or science?

People frequently want the easy way to correct their health issues. They want to imbue a magical quality to “natural” products to make themselves healthier. They don’t want to take one of those evil Big Pharma drugs. For example, over the past few years, Big Supplement has pushed a belief that cinnamon for diabetes is a great treatment.

But really, do these supplements actually do all that much? Well, the real scientific evidence gives little support to the health benefits of these various supplements. I’ve probably written over 50 articles on supplements, and maybe one supplement has any value in health.

Look at cancer prevention. There really are only a handful of ways to prevent cancer, and none of them include megadoses (or even single doses) of supplements.

We probably see a million advertisements for supplements and “natural” foods that make you thinner, healthier, smarter, stronger, better. Of course, if even 1% of the claims (or outright fabrications) made by these hawkers were supported by real science, we could close down Big Pharma and all those physicians hawking those evil drugs that aren’t necessary.

Except, we know that’s not true. And it’s time to look at the claims of cinnamon for diabetes – what is the real science.

All about diabetes

Lots of science here, but diabetes is a complex disease. Oversimplifying it can make some people think that it’s simple to treat or even cure. I need to disabuse the reader of that belief if you have it.

What is Type 1 diabetes? The basic power source of our body is glucose, which is produced from almost anything we eat (carbohydrates, proteins, sugars, and fats). It is usually tightly regulated by the body, that when you have excess glucose in the blood, it is taken out of the blood and stored–but when the blood glucose drops, it is then released from storage to be used for energy.

The key hormone, insulin, which regulates the level of glucose in the body is released by the Beta cells of the Islets of Langerhans in the pancreas when blood sugar goes up–insulin induces storage cells to remove and store glucose from the blood. In a complex interaction, the hormone glucagon, produced by other cells in the pancreas when the blood glucose level is too low, which then induces release of that stored glucose.

This shows, once again, how complex living systems are, and simple explanations about the physiological processes in humans are laughable and should be dismissed. Moreover, glucose control in humans is a fascinating physiological system, and it’s remarkable that it works so well in 99% of people.

Back to diabetes. Type 1 diabetes (T1D) is an autoimmune disease where the body’s own antibodies attack the Islets of Langerhans, causing the production of insulin to drop or even to be halted. As of today, there are no cures, and the only way to treat someone is to regularly inject human insulin, which is produced by bioengineered E. coli. 

Before the wide availability of insulin in the 1920’s (usually pig insulin whose structure is similar to human insulin, but still caused a lot of allergic reactions), children simply died of the disease. Nothing could be done.

T1D should not be confused with two other types of diabetes, one called latent autoimmune diabetes of adults (sometimes called LADA or Type 1.5 diabetes), but really has no practical difference with T1D except age of the commencement of symptoms. Instead of showing symptoms as a child, it appears in late adulthood, typically 30’s and early 40’s. Like typical Type 1 diabetes, the only treatment for LADA is insulin injections.

The other form is Type 2 diabetes (T2D), which is probably caused by a combination of genetics, obesity, eating behavior, and several other lifestyle factors. Usually in T2D, the pancreas produces sufficient insulin, but the body’s cells and organs become “resistant” to the insulin, meaning that they ignore the signal to store glucose, and thus the blood glucose remains high.

Oral medications, behavioral changes, such as improved diet and exercise, can often help manage if not reverse T2D. Eventually, a person with chronic T2D may also have to take insulin.

Type 1 and Type 2 diabetes are truly two different kinds of diseases with one common symptom, excess blood glucose levels.

There is a form of diabetes called gestational diabetes, which results in high blood sugars in pregnant women, usually in the third trimester. Unfortunately, it is not well understood what causes it, and if it remains untreated, it could lead to other types of diabetes.

T2D is the most prevalent form, making up about 90-95% of all diabetes, and is a type of metabolic disease that can be treated without medication through weight loss, dietary modification and exercise. However, since all of those treatments are hard work, oral diabetes medications and insulin are eventually prescribed for the treatment of the disease, when the blood glucose remains out of control.

There is a strong correlation between type 2 diabetes and obesity, although there are other risk factors like genetics and sleep habits. Across the world, type 2 diabetes has skyrocketed from 30 million in 1985 to 285 million in 2010. In the USA, 8.3% of the population has diabetes, which costs the country about $116 billion in direct medical spending.

cinnamon for diabetes

Cinnamon for diabetes treatment

In 2013, a paper was published, a systematic review which I consider to be near the highest top level of scientific publication, that claimed that consuming cinnamon might reduce blood glucose levels. Based on this study, maybe there is an easy way to treat diabetes. Just sprinkle cinnamon on everything, and diabetes disappears.

But let’s look at this review more carefully.

The meta-analysis included 543 patients in 10 different randomized clinical trials (or an average of 54 per clinical trial, an extremely small number). In fact, the range of patient numbers in each arm of these studies ranged from a low of 7 (really, 7 patients?) to a high of 30. I would contend that rolling up averages from a bunch of small studies doesn’t necessarily increase the statistical power of the studies. In fact, it might exacerbate the statistical issues.

One of the more frustrating aspects of this analysis is that they claim that cinnamon reduces blood glucose by 24.59 mg/dL of blood. Well, you might think that is a great reduction, except it is significantly less than a reduction of 58 mg/dL shown by one of the more common oral diabetic medications, metformin.

Furthermore, the authors frustratingly did not include the actual blood glucose level but just the reduction. A drop from 240 to 216, or a reduction of 24 mg/dL, is not necessarily clinically significant – one of the hallmarks of science-based medicine is whether a claimed treatment has an actual and measurable clinical benefit.

In fact, at the level of blood glucose reduction stated in the paper, patients still have significant risks from complications of diabetes over both the long and short-term. Finally, the systematic review showed no reduction in hemoglobin A1C levels, an important blood marker, which provides information about the long-term changes in a patient’s blood glucose.

In other words, cinnamon induced clinically insignificant decreases in blood glucose, but, more importantly, didn’t reduce the one diagnostic marker that would indicate a reduction of blood glucose over a longer period of time.

Another systematic review, published in 2012, showed nearly the same results for cinnamon – reduction in blood glucose only 1-10% of what has been observed with other types of oral diabetes medication. And, as we’ve seen before, the reduction in blood glucose is so small as to be clinically insignificant.

Another meta-review, highlighting the importance of not cherry picking peer-reviewed papers, published in the respected journal Diabetes Care, also examined cinnamon’s effect on diabetes. Their unsurprising conclusion: “Cinnamon does not appear to improve A1C, FBG, or lipid parameters in patients with type 1 or type 2 diabetes.”

A 2015 review came to the same conclusion as many others have – “At present, the evidence is inconclusive and long-term trials aiming to establish the efficacy and safety of cinnamon is needed.” And let’s not fall for the argument from ignorance – the lack of evidence doesn’t mean the evidence is going to show up tomorrow!

Now, some might then conclude if a few grams of cinnamon might reduce blood sugar, then maybe a whole bunch of it will treat diabetes. Even though the naturalistic fallacy might make one think that good, natural cinnamon is safer than Big Pharma’s drugs, that would be an incorrect assumption.

Finally, and this is the most important point, commonly accepted medications for diabetes, like insulin or metformin, have actually been shown to reduce mortality from diabetes. Cinnamon for diabetes has never been shown to reduce diabetes-related mortality, a key endpoint for all diabetes treatments.

Some kinds of cinnamon contain coumarin, a compound that could be toxic at higher levels. Even if the risk is moderate, the evidence of efficacy (at least with diabetes) is lacking. It is not logical to take even a slight risk for a minor or probably nonexistent effect.

The blog Science-Based Medicine took a look at cinnamon for diabetes – they found nothing:

Cinnamon’s effectiveness as a treatment for diabetes has not been established. A prescription drug as ineffective as cinnamon likely wouldn’t pass FDA muster. Existing drug treatments for diabetes, on the other hand, are cheap, effective, and generally well tolerated. Compared to drug therapy, we don’t know if cinnamon can reduce the risk of mortality due to diabetes, or the progression to any of the other serious outcomes of diabetes.

For my patients that insist on trying cinnamon, I’d caution them of the risks, and reinforce that cinnamon is no alternative for lifestyle changes and medication if necessary. It may be natural, sure, but that doesn’t mean it’s either safe or effective.


Current treatments for all forms of diabetes are generally inexpensive, well tolerated and do what they’re supposed to do – reduce blood sugar and related issues. And if you’re looking for a “natural” way to control blood sugars, there is nothing more natural than human insulin to do its job in controlling blood sugar–admittedly, insulin is only appropriate for type 1 and certain kinds of type 2.

In conclusion, the evidence for the clinical usefulness of cinnamon in treating blood glucose levels is remarkably weak, if not nonexistent. If you have been diagnosed with any form of type 1 diabetes, there is simply one treatment –insulin injections.

If you’ve been diagnosed with pre-diabetes (the preliminary step before type 2 diabetes) or full-blown type 2 diabetes, well, there’s losing weight and exercise, followed by certain oral diabetic medications. Yeah, I know it’s hard. There’s not going to be something as easy as downing a cinnamon pill.

Editor’s note – this article was first published in March 2016. It has been updated for copyedits and to fix broken links. 

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