Thursday, September 30, 2010

Seventeen Articles on Cinnamon

In September we are looking in depth at cinnamon as a treatment for type 2 diabetes, the positive studies, the negative studies, and some stubborn misunderstandings about the two types of cinnamon used in blood sugar control. Comments and questions are welcome. Allow us 24 hours to moderate all postings to our articles.

The First Clinical Tests of Cinnamon for Diabetes

Around the year 2000, scientists at the Department of Human Nutrition, NWFP Agricultural University, Peshawar, Pakistan and the US Department of Agriculture in Beltsville, Maryland, decided to see if the burgeoning research into the "insulin-like properties" of cinnamon could be used to help actual diabetics in Pakistan.

You've probably heard something about the results. We'll mention more about that in a minute. But first we'd like to consider one aspect of the study that is usually forgotten. The scientists were seeking to help real diabetics with real herbs that could get, not herbs they couldn't.

That gray, dusky, dull, bitter kind of cinnamon known botanically as Cinnamomum cassia is the kind of cinnamon you can buy in Pakistan, usually for mixing into your curry. It's cheap. It's universally available. It's not exactly a favorite food, but everyone knows what to expect from it.

In a country where even metformin was out of reach for most type 2 diabetics, using cinnamon powder held promise as an amazing boon. But it's important to remember this was the only treatment the participants in the trial had.

The often-recited results of the Peshawar study were:

RESEARCH DESIGN AND METHODS: A total of 60 people with type 2 diabetes, 30 men and 30 women aged 52.2 +/- 6.32 years, were divided randomly into six groups. Groups 1, 2, and 3 consumed 1, 3, or 6 g of cinnamon daily, respectively, and groups 4, 5, and 6 were given placebo capsules corresponding to the number of capsules consumed for the three levels of cinnamon. The cinnamon was consumed for 40 days followed by a 20-day washout period.
RESULTS: After 40 days, all three levels of cinnamon reduced the mean fasting serum glucose (18-29%), triglyceride (23-30%), LDL cholesterol (7-27%), and total cholesterol (12-26%) levels; no significant changes were noted in the placebo groups. Changes in HDL cholesterol were not significant.

Wow! Something that costs about a penny a day lowers blood sugars, triglycerides, LDL cholesterol, and total cholesterol, without lowering HDL. Didn't this make cinnamon some kind of herbal wonder drug?

Again, it helps to read the actual study.

First of all, more was not better. The best results were from the lowest dosage, just 1,000 mg a day. If you have been reading our other blogs, you'll notice that this also a dosage assured not to cause side effects from thinning the blood.

Secondly, the benefits of cinnamon took 20 days to build up and lasted at least 20 days after participants in the clinical trial stopped taking it. It obviously wasn't working as
"plant insulin." Somehow, someway cinnamon was working on insulin resistance.

Selected Reference:

Khan A, Safdar M, Ali Khan MM, Khattak KN, Anderson RA. Cinnamon improves glucose and lipids of people with type 2 diabetes.Diabetes Care. 2003 Dec;26(12):3215-8.

Two Kinds of Cinnamon

We want to give special attention to that most controversial of all the Ayurvedic herbs for type 2 diabetes, cinnamon. One of the ongoing questions about cinnamon is whether the kind of cinnamon people in Europe and most of the English-speaking world use is the same kind of cinnamon tested as a treatment for diabetes.

It's not. It's as simple as that.

The kind of cinnamon tested as a treatment for type 2 diabetes is Chinese cinnamon, known in botany as Cinnamomum cassia. The kind of cinnamon hundreds of millions of people consume with their cinnamon rolls is Ceylon cinnamon, Cinnamomum zeylanicum. More than just the Latin names are different.

Chinese cinnamon is bitter. Ceylon cinnamon is aromatic. The bark used to make Chinese cinnamon is grayish. The bark used to make Ceylon cinnamon is reddish. And in the words of world-renowned spice botanist Gernot Katzer, "Cassia bark contains significantly more slime (11%) than Ceylon cinnamon bark."

Slime slows down digestion of sugars, and for most type 2 diabetics most of the time, that is a good thing. However, there are other chemical considerations we'll mention a little later.

In southern India, by the way, the word for cinnamon describes yet another herb, the one we in the English-speaking world call cloves. Don't try to keep up with all the distinctions. Just look for Cinnamomum cassia on the label, if you choose to take cinnamon as an aid for type 2 diabetes.

A Possible Downside to Using Cinnamon for Type 2 Diabetes

As we mentioned in another post, when it comes to treating type 2 diabetes, cinnamon most often means Cinnamomum cassia, the bitter, blackish "curry cinnamon" used in Indian cuisine, not the aromatic, reddish "sweet cinnamon" used in baking. There is, however, a potential downside to taking cinnamon if you are getting treatment for blood clots.

Cinnamomum cassia contains detectable concentrations of coumadins. These are chemicals that work in the same way as warfarin, Plavix, Trental, and other medications to help maintain circulation. The herb, however, does not contain large amounts of coumadins.

As is often the case with such matters, the controversy about the coumadins in cassia began in a relatively silly way. Although the spice is not used for baking in Germany, in 2006 the Bundeinstitut für Arzneimittel (the German equivalent of the US FDA) expressed concern that if it were, it could cause some people problems. Specifically, if you added enough of this kind of cinnamon to cookies that you were sure they tasted bad, then people who ate this kind of cinnamon in baked goods because they prefer bitter cookies to sweet cookies (yeah, right) might then absorb too much of the coumadins.

But let's assume there really are such people. Obviously, the German federal administrators do.

If you allow a 10-fold safety factor, keeping consumption to less than 10% of the amount that could cause problems, the BfürA eventually decided, then a person who weighed at least 50 kilos (110 pounds) could consume 1,000 mg of this kind of cinnamon safely every day, and a person who weighed at least 100 kilos (220 pounds), 2,000 mg.

What all the deliberations left out is that the tastier kind of cinnamon also contains coumadins, in about the same concentration. If the kind of cinnamon that has an effect on type 2 diabetes might interfere with blood clotting, then it happens that the tasty kind of cinnamon (that's usually added to sugary sweets in English-speaking countries, although it's used with savories in Latin America) should be restricted, too. It's not. Apparently something has to be competitive with a medication to merit a cautionary note.

There have been no reports of "cinnamon poisoning" even among people who use up to 6,000 mg a day. We recommend that anyone who is taking any kind of prescription blood thinner avoid cinnamon entirely, and that anyone inform the doctor of taking the herb. It will help the doctor notice unusual patterns of blood clotting should a blood thinner ever be needed. But we certainly recommend that type 2 diabetics avoid cinnamon rolls and cinnamon candies.

What the Earliest Research on Cinnamon Said

There's been a great deal of obfuscation by the anti-herbal crowd on the uses of cinnamon in treating type 2 diabetes. We are not necessarily pro-herbal. We're just very much in favor of treatments that work for people who can afford them.

Back in the 1990's there were studies of the red, aromatic, sweet Cinnamomum zeylanicum kind of cinnamon at Iowa State University. Researchers believed there was some kind of water-soluble compound in this kind of cinnamon with which most North Americans, Britons, Australians, and New Zealanders are familiar that imitated insulin. What you won't get by reading the abstract on MedLine is that the insulin-like compound in the study was only soluble in hot water. (Or hot alcohol, if you happened to be inclined to make a hot cinnamon toddy.)

This is very interesting laboratory research that essentially went nowhere. Later studies with real live people were done with a different kind of cinnamon.

Selected Reference:

Imparl-Radosevich J, Deas S, Polansky MM, Baedke DA, Ingebritsen TS, Anderson RA, Graves DJ. Regulation of PTP-1 and insulin receptor kinase by fractions from cinnamon: implications for cinnamon regulation of insulin signalling.Horm Res. 1998 Sep;50(3):177-82.

The Model of Insulin Resistance Addressed in Cinnamon Research

In our articles and blog posts, we often explain insulin resistance as a process through which cells "shut the door" to glucose transporters so that they can avoid getting flooded with glucose, and the subsequent release of free radicals when the glucose is metabolized as fuel. Insulin resistance is, in this scheme, a self-protective mechanism on a cellular level that protects the integrity of cell structures and DNA. This model of insulin resistance also explains why antioxidants like alpha-lipoic acid, for instance, help reverse insulin resistance.

In the studies of cinnamon as treatment for type 2 diabetes in the late 1990's and early 2000's, however, many scientists were operating with a different model of insulin resistance. The theory at that time was that too much sugar in the bloodstream led to a kind of caramelizing of the linings of capillary walls, and kept glucose from reaching the cells that would absorb it. Reversing insulin resistance, then, was more of a mechanical matter. Knock the crud out of the pipes, and in the sugar goes. Rather like the commonly articulated theories of cholesterol at the time.

With this model of insulin resistance, it was only natural that the discovery of Turkish scientists that giving lab rats massive doses of cinnamon reduced the number of platelets would be considered evidence that the herb could help control diabetes (by introducing another abnormality). We do not, however, advocate using any dosage of cinnamon that would actually do this! As is the case with so many medications and complementary therapies, more is not necessarily better.

Selected Reference:

Onderoglu S, Sozer S, Erbil KM, Ortac R, Lermioglu F. The evaluation of long-term effects of cinnamon bark and olive leaf on toxicity induced by streptozotocin administration to rats.J Pharm Pharmacol. 1999 Nov;51(11):1305-12.

Other Plant Foods with Insulin-Like Activity

Other Plant Foods with Insulin-Like Activity

In all the focus on cinnamon, it is generally overlooked that while cinnamon had the most insulin-like activity of any plant food tested, it was hardly the only plant food that seemed to act in the body the same way as insulin. Allspice, bay leaf, brewer's yeast, cloves, nutmeg, witch hazel, green tea, black tea, and certain mushrooms all were found to have the same effect on fat cells in the test tube. They contained compounds that acted in the same way as insulin.

Robert can take the story a bit farther. Some years ago Robert was privilege to work for a genuine rain forest explorer who had isolated a tropical plant that contained a high concentration of "plant insulin." Robert volunteered to drink a cup of tea made with the herb, and promptly went into hypoglycemic shock. Fortunately, he had glucose at the ready. Robert vowed never to do such a silly thing again. And to keep others from doing such a thing, he also vows not to reveal the name of the herb (unless it ever reaches the market).

Don't be the first person to test an herb for blood sugar control. Use products that have already been tested on real people under medical supervision. Cinnamon, as we will discuss in our next post, is such a product, but allspice, bay leaf, brewer's yeast, cloves, nutmeg, witch hazel and tea, at least as a blood sugar treatment, are not.

Selected Reference:

Broadhurst CL, Polansky MM, Anderson RA. Insulin-like biological activity of culinary and medicinal plant aqueous extracts in vitro. J Agric Food Chem. 2000 Mar;48(3):849-52.

Meanwhile, Adding to the Confusion about Cinnamon for Type 2 Diabetes

Shortly after the Pakistani study was published, scientists at the United States Department of Agriculture in Beltsville, Maryland released their laboratory findings of more indications of insulin-like properties of cinnamon--by which they meant the reddish, aromatic, sweet-tasting kind of cinnamon used in North America and the rest of the English-speaking world, not the dull, gray, bitter cinnamon that had just been tested in the clinical trial. The Beltsville scientists concluded that:

"These polyphenolic polymers found in cinnamon may function as antioxidants, potentiate insulin action, and may be beneficial in the control of glucose intolerance and diabetes."

These were not, however, polymers that can be obtained by eating cinnamon. They can only be obtained by processing with heat. However, they were not necessary for the good results of taking the other kind of cinnamon!

Confusing? Please stay with us. The story gets much better.

Selected Reference:

Anderson RA, Broadhurst CL, Polansky MM, Schmidt WF, Khan A, Flanagan VP, Schoene NW, Graves DJ. Isolation and characterization of polyphenol type-A polymers from cinnamon with insulin-like biological activity.J Agric Food Chem. 2004 Jan 14;52(1):65-70.

The First European Test of Cinnamon for Type 2 Diabetes

About as soon as the results of Pakistani cinnamon study were published, European scientists sought to debunk or duplicate them in independent trials. A group of five medical researchers at the research institute and hospital in Maastricht in the Netherlands tested a 1,500 mg dose of the same kind of cinnamon used in the Pakistani study as a treatment for post-menopausal women who had type 2.

There was a very important difference between the men and women in the Pakistani trial and the women in the Dutch trial. All but 4 of the 25 women in the Dutch trial were already receiving medications. The Dutch scientists did not report separate data for these 4 women.

The bottom line of the data analysis was that the effects of taking cinnamon did not rise to the level of statistical significance. Cutoffs for statistical significance are subjectively determined, but there is probably no acceptable level of statistical significance that would have given the results of this study a different interpretation. Cinnamon seemed to be beneficial, but just a little, not really a significant difference.

Except for one huge difference. The women in the study were already receiving medications. Perhaps the unspoken benefit of cinnamon is that it works when needed, and not when not needed. There is nothing in this study, however, that says someone should take cinnamon instead of a doctor-prescribed medication.

Selected Reference:

Vanschoonbeek K, Thomassen BJ, Senden JM, Wodzig WK, van Loon LJ. Cinnamon supplementation does not improve glycemic control in postmenopausal type 2 diabetes patients.J Nutr. 2006 Apr;136(4):977-80.

The Hannover Study of Cinnamon for Type 2 Diabetes

Clinical trials are the way we prove drugs--and herbs--are safe and effective. In April of 2006 there had been one clinical trial that found that cinnamon was practically a wonder drug for type 2 diabetes, and a second clinical trial that found that it was of no value at all. Could is possibly that no single herb, like no single drug, is best for all type 2 diabetics?

That is what a German study published in May 2006 tells us. Giving volunteer diabetics either three placebo capsules a day or three 1,000 mg cinnamon extract capsules a day, the scientists concluded that:

"The cinnamon extract seems to have a moderate effect in reducing fasting plasma glucose concentrations in diabetic patients with poor glycaemic control."

The higher the starting blood sugar levels, the better the results of treatment. Perhaps cinnamon somehow "unclogs" the linings of capillaries so cells can accept sugar more readily from the bloodstream, and once it's done its job, there's nothing more for it to do. Or perhaps there is.

Selected Reference:

Mang B, Wolters M, Schmitt B, Kelb K, Lichtinghagen R, Stichtenoth DO, Hahn A. Effects of a cinnamon extract on plasma glucose, HbA, and serum lipids in diabetes mellitus type 2. Eur J Clin Invest. 2006 May;36(5):340-4.

The Dartmouth Study of Cinnnamon for Type 1 Diabetes

A severely negative finding in the research into cinnamon as a treatment for diabetes was reported by researchers at Dartmouth Medical Center in the USA. The Dartmouth researchers decided to test cinnamon as treatment for diabetics among a group of diabetics who need all the help they can get, adolescents with insulin-dependent, type 1 diabetes. The researchers set about to ascertain whether taking cinnamon would lower HbA1C levels in 90 days, indicating benefit for 24-hour blood sugar control.

It didn't.

However, HbA1C is usually a measure of the glycation of red blood cells over 120 days, not 90. It's almost as if the researchers wanted to make absolutely sure that cinnamon would not be helpful, so they took their measurements before it could have effect.

Selected Reference:

Altschuler JA, Casella SJ, MacKenzie TA, Curtis KM. The Effect of Cinnamon on A1C Among Adolescents With Type 1 Diabetes. Diabetes Care. 2007 Apr;30(4):813-6.

But What About the More Common Kind of Cinnamon for Type 2 Diabetes?

In our previous posts we've uncovered studies about curry cinnamon for type 2 and type 1 diabetes. There has also, however, been research into the usefulness of the better known aromatic, reddish brown cinnamon as an adjunct treatment for type 2.

Swedish scientists have found that adding 6 grams (2 teaspoons or so) of cinnamon to 300 grams (4 cups) of rice pudding slows the release of sugars by about 35%. Adding cinnamon to your starchy, sweet foods blunts their impact on blood sugar, for sure.

But no type 2 diabetic should ever consume 300 grams of rice pudding in a single serving! The research indicates that spoon or two of cinnamon may be helpful in preventing blood sugar spikes after meals, but you still need to restrict your carbohydrate consumption, since all the carbs will eventually be digested!

Selected Reference:

Hlebowicz J, Darwiche G, Björgell O, Almér LO. Effect of cinnamon on postprandial blood glucose, gastric emptying, and satiety in healthy subjects. Am J Clin Nutr. 2007 Jun;85(6):1552-6.

Cinnamon for Prediabetic Men and Women

One of the more interesting but less often discussed applications for cinnamon is in health enhancement for pre-diabetic men and women, persons who may have "borderline" high blood sugar levels, cholesterol, and triglycerides, along with high blood pressure and bulging waistlines.

A study of cinnamon for prediabetic men and women conducted in northeastern found that taking the commercial product Cinnulin PF for two weeks:

  • Reduced blood pressure (systolic) about 5 mm Hg,
  • Reduced blood sugar levels about 10 mg/dl,
  • Increased lean body mass about 1%, and
  • Decreased fat mass about 0.7%.

The recommended daily dosage of two capsules of the Cinnulin PF product is claimed to be the equivalent of about 10 grams of powdered cinnamon. It concentrates the polyphenols believed to be most active in blood sugar regulation.

The test ran for a very short time, and got very small, but statistically significant results (which is hard to do when you only have 22 volunteers for your trial). The test did not find changes in triglycerides or cholesterol, but this can be explained by the fact that volunteers in the study did not have high triglycerides or high cholesterol. The changes in blood sugar levels, while beneficial, were not substantial enough to affect fats in the bloodstream (which didn't need treatment, anyway).

This is a preliminary study, but anything that helps prediabetics lose weight seems worth a second look.

Selected Reference:

Ziegenfuss TN, Hofheins JE, Mendel RW, Landis J, Anderson RA. Effects of a water-soluble cinnamon extract on body composition and features of the metabolic syndrome in pre-diabetic men and women.
J Int Soc Sports Nutr. 2006 Dec 28;3:45-53.

Cinnamon for Sleep Loss-Induced Insulin Resistance

From Baylor University in Waco, Texas comes research that has found that finds that taking cinnamon products may be beneficial in dealing with insulin resistance caused by sleep loss. Not getting enough sleep accelerates prediabetes and causes the pancreas to have to work overtime to keep blood sugar levels down. The extra insulin secreted by the beta cells to maintain normal blood sugar levels remains available for storage of fat.

The biochemistry of signaling proteins is a bit more than we care to discuss here. The bottom line of the Baylor study, however, is that if you are a stressed out, sleep deprived prediabetic, cassia cinnamon and cassia cinnamon extracts may help you avoid the progression of your condition to full-fledged type 2 diabetes.

Selected Reference:

Jitomir J, Willoughby DS. Cassia cinnamon for the attenuation of glucose intolerance and insulin resistance resulting from sleep loss.
J Med Food. 2009 Jun;12(3):467-72. Review.

Monday, September 27, 2010

The Study on Cinnamon for Diabetes that Will Appear Next Month in Diabetic Medicine

Here at the Diabetes Detectives, we do our very best to help you stay completely up to date on the latest developments for keeping type 2 diabetes in good control. In that spirit, we would like to tell you about a study that will be appearing in October 2010 in the British journal Diabetic Medicine.

Drs. Akilen, Tsiami, Devendra, and Robinson of the Thames Valley University, Imperial College London, and National Health Service recruited 25 men and 33 women with type 2 diabetes who were not being treated with insulin. These volunteers were not "well controlled." The average HbA1C of the volunteers was 7.0%.  That's equivalent to an average fasting blood sugar of at least 145 mg/dl or so, depending on how the lab runs the test.

Half the volunteers received 2 grams of a placebo and half the volunteers received 2 grams of cinnamon every day for 12 weeks. At the end of the trial, HbA1C was down an average of about 0.6% in the cinnamon group, essentially unchanged in the placebo group. Users of cinnamon had lower average fasting blood sugar levels, lower blood pressure, lower waist circumferences, and "lower BMI." Assuming cinnamon did not cause volunteers in the test group to grow taller, this must mean that they lost weight.

None of the researchers conducting the study suggests that cinnamon is a "cure" for diabetes, but in this latest of over 60 studies, it at least appears to be quite helpful. Once again, as in earlier research, the type 2 diabetics who were helped the most by cinnamon were those who had the poorest control over their blood sugar levels. Cinnamon seems to be an aid to blood sugar control that works when you need it, and has no special effects when you do not.

About Robert

What is an MBA doing blogging about type 2 diabetes? If you have diabetes, you know that taking care of your condition can cost a small (or large) fortune. Robert Rister is also a formulator of natural products, an consultant to companies on regulatory issues, and the author of five printed books and over 30 ebooks on diabetes and other health concerns.

Robert found out he was a diabetic in a shocking manner. Despite biking 150 miles a week after work and getting lots of exercise working on a farm, plus getting good reports on his physicals, one day Robert suddenly found he was blind. ER doctors discovered his sugars were over 500 mg/dl and he was dehydrated and near death, this happening just six weeks after a complete physical had found nothing. Robert regained his sight and is now free of diabetic complications--but still has to be vigilant every day. Robert writes about the things type 2 diabetics need to know to keep their symptoms under control while living (and even eating) well.

Saturday, September 11, 2010

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