1 August 2007

Low GI Food of the Month

Cinnamon and cassia – don’t go barking up the wrong tree
Back in August 2006 we wrote about two promising studies reporting that as little as the equivalent of ¼ teaspoon of cinnamon daily may improve blood glucose control. Cinnamon is in the news again with a report in the June American Journal of Clinical Nutrition (Vol 85 No. 6) concluding that adding 6 grams (about a teaspoon) of cinnamon to 300 grams of rice pudding delays stomach emptying and reduces blood glucose levels. We wondered how feasible it is to eat 6 grams of cinnamon (that’s more than a teaspoon) at a sitting? ‘Perfectly feasible,’ says Ian Hemphill author of the Spice and Herb Bible (Spice Notes in Australia), ‘so long as it really is true cinnamon. I do it every morning stirring it into my porridge while it is cooking.’ But then he asked a curly question – had the researchers used true cinnamon in their study or was it cassia they were actually talking about!

Why? Well, true cinnamon (Cinnamomum zeylanicum Ceylon cinnamon) is easily and regularly confused with cassia (Chinese cassia C. cassia, Batavia cassia C. burmannii and Saigon cassia C. loureirii ). ‘Everybody is confused,’ says Ian ‘from consumers, to traders, processors and even the growers themselves. It is virtually impossible for the average consumer to tell the difference. In some countries it is illegal to sell cassia as cinnamon, but there’s very little policing, so it hardly has any effect. And the label won't help although the country of origin may give a clue. In the US for example, true or Ceylon cinnamon is almost unheard of, so anything called cinnamon is bound to be cassia, unless it’s Mexican cinnamon – this is because Mexico buys so much true cinnamon from Sri Lanka that the traders there have a grade of cinnamon called ‘Mexican’!


So, what’s the difference between 'true' cinnamon and 'cassia' cinnamon and does it matter? ‘For starters,’ says Ian, ‘the best cinnamon is a very thin underneath layer of bark from a quite young piece of branch, while cassia is the complete thickness of bark from the fully grown tree. And there are some significant differences in aroma and use. The aroma of cinnamon is delicate, sweet and subtle, and it's virtually impossible to use too much in your cooking. Cassia has a highly fragrant cinnamon aroma when it is ground, but you need to use moderation – too much cassia spoils the flavour and 6 grams in some dishes might be rather unpalatable.'

In addition, if people want to add ‘cinnamon’ to their cooking to help with blood glucose levels, then they need to be adding the one that's been tested. Cassia cinnamon was actually the spice (or supplement) used in the various studies published to date in Diabetes Care 26:3215-3218, 2003, the European Journal of Clinical Investigation Vol 36, No 5, and the latest one in the American Journal of Clinical Nutrition. Why? Well cassia has significant amounts (around 5%) of coumarin, while true cinnamon only has traces. If you want to know more about coumarin in cinnamon (and other foods for that matter), check out the fact sheet on Germany's Federal Institute for Risk Assessment (BfR) website: http://www.bfr.bund.de/cd/8487.

Meanwhile whether it’s true cinnamon in your spice rack or cassia cinnamon, 'they are both a great addition (in appropriate amounts) to smoothies, cakes, poached and stewed fruit for breakfast or a dessert, and for spicing up veggies such as pumpkin and zucchini (courgettes),' says Ian. For more ideas check out Herbies Spices: www.herbies.com.au


Herby said...

this article is confusing: what type of cinnamon should be consumed, or does it not matter? The article says that "cassia" was tested and showed the results but then the author refers to "young" cinnamon as the true one to use.

Anonymous said...

If you want to add cinnamon to recipes for blood glucose control, then you need to make sure that it's cinnamon cassia. And if you live in the US, that's what it is likely to be. Otherwise it probably doesn't matter unless you are a foodie and very fussy about flavour. What is sold as ground cinnamon comes from different trees. We thought we spelled out clearly that a common or popular name for Cinnamomum zeylanicum is 'true cinnamon'.

Anonymous said...

What is the risk of daily eating high dose of cinnamon while it is containing coumarine. In animalstudies coumarine is carcinogen! Sea p.e. articals on www.efso.europa.eu

Anonymous said...

We aren't experts in this area which is why we gave website details for the Federal Institute for Risk Assessment. It is something they have reviewed carefully. Here is is again: www.bfr.bund.de/cd/8487.

Anonymous said...

I agree that this article is quite confusing, even with the subsequent explanation...If it is feasible to add 6 grams of cinnamon to porridge, but it should be 'true cinnamon' (Ian Hemphill. I understand from the article however that it is cassia that was tested, and which is recommended. It seems that these two statements are at odds, hence some confusion.

Anonymous said...

It's not the article that's confusing. It's what's happening out there in the food industry and the lack of clear labelling of this spice.

If you love the flavour of cinnamon and want to add it to food, do it. And don't worry about what's in the packet of cinnamon (or jar) you buy.

Ian happens to like the taste of true cinnamon. He reckons that adding 6 grams of cinnamon cassia isn't the same at all.

But it's over to you what you add.

If you have diabetes and want to add cinnamon to your porridge or rice pudding to help manage your blood glucose levels, you need to add cinnamon cassia.

All we are saying is that you may need to ask the manufacturer what's in the packet because from our experience his label won't tell you anything useful at all.

Anonymous said...

Everyone should read the article on www.bfr.bund.de/cd/8487.
Specially the cassia cinnamon contains high levels coumarine.
They advice to avoid eating large amounts of this cinnamon.

Anonymous said...

I am further confused by the comment to add cinnamon to rice pudding. As a type 2 diabetic, I cannot eat any rice without seeing a big increase when I test my blood sugar afterwards....

Liane Colwell said...

This debate highlights the importance of using botanical, or scientific names, when discussing medicinal or therapeutic actions of herbs, spices, and vegetables etc. The advantage of using such names is that they give an unambiguous classification, which is internationally understood, making journal articles more comprehensible, and facilitating a clearer debate between the GI Newsletter subscribers.

The subject GI study was based on Cinnamomum cassia, or Cassia Cinnamon, also known as Chinese Cinnamon, Bastard Cinnamon, Cassia lignea, Cassia bark, Cassia aromaticum and Canton Cassia. For ease of understanding my contribution, I will call this spice, Cassia. With these additional synonyms you will be able to further research/’surf‘ this subject. Cassia is related to, but different to, Cinnamomum zeylanicum, which I will call Cinnamon.

The effect on GI, the subject of the study in question was based on Cassia, in a dried and powdered form. Cassia is widely used for baking in America, where it is marketed and sold as ‘Cinnamon,’ hence the misunderstandings in our debate.*

There are culinary and medicinal differences between Cassia and Cinnamon. Cinnamon is sweeter and more delicate, while Cassia is slightly bitter and more pungent. Cassia is cheaper, and is often substituted for Cinnamon. They are comparable in terms of some of their medicinal applications. In China, Cassia, is used medicinally to such an extent as to be spoken of as a ‘cure-all.’ Such is the experience of traditional Chinese medicine practitioners in using Cassia, that there are about 30 conditions for which Cassia is contra-indicated, that is, should be avoided. These include excessive menstrual flow, bloody urine, nosebleed, difficulty in urination, loss of voice, haemorrhoids, and most importantly, pregnancy.

This contraindication for pregnancy was confirmed in several sources including, The Essential Book of Herbal Medicine by Simon Y Mills, the respected British herbalist. The contra-indication in pregnancy, applies to both Cassia and Cinnamon, but only when used in medicinal quantities, such as the 6 g per 300g of rice pudding. [A curry might have as little as ¼ teaspoon for 6 servings].

To this I would add, that a prime precaution in cooking with, or eating, both ground Cassia and Cinnamon, is that they should be used carefully. They are both very dry spices, and capable of irritating the throat of an unwitting diner. This can lead to [extended] coughing fits. I love the taste of both, and cook with both, but in using them, in large quantities like in Moroccan tagines, I have inadvertently eaten a chunk of the undissolved powder on occasion. Both Cassia and Cinnamon can be used as a garnish, and while they look great, they can tickle the throat for some time afterward. Spices must always be used with care when cooking for children, as kids can choke on pieces of Cassia or Cinnamon quills [the bark], or get an undissolved lump of the ground spice, caught in the throat.

I checked the BfR reference “Frequently asked Questions about coumarin in cinnamon and other foods,” and was disappointed to find that the article represents “coumarin” as one substance. From my Pharmacognosy studies I can report that it is, in fact, a class of substances, and is found in about 30 plant families, including the grass and legume families. The ‘coumarin’ class of compounds include; herniarin, chalepensin, coumestrol, umbelliferone, scopoletin, a subclass called furanocoumarins, and dicoumarol. As a heterogenous group, they have a large range of effects, so I caution readers to be wary of avoiding coumarins per se, on the basis of this one article.

The BfR article distinguishes between Cassia and Cinnamon only on the basis of the coumarin content; “Ceylon cinnamon only contains low levels of coumarin which are safe from the Institute’s risk assessment perspective.” This “Ceylon cinnamon” is Cinnamomum zeylanicum which I call Cinnamon.

I am sceptical about the recommendations on the Tolerable Daily Intake because the article is full of generalisations as implied by the repeated use of the term “coumarin,” without specifying which one. I am also wary of advice such as, “only offer cinnamon-containing biscuits on a limited scale after talking to parents.” Cinnamon and Cassia are cornerstones of many traditional dishes, cuisines and spice blends like Chinese 5 Spice Mix, so this is probably over-cautious.

I haven’t read the whole study yet, but coumarin is not the only constituent of Cassia [or Cinnamon], implicated in the desired hypoglycaemic [GI-lowering] effect. Cinnamaldehyde constitutes between 75 and 90% of the volatile oil content of the Cassia and the volatile oil content of Cassia varies between about 2 and 5% of the spice, by weight. The cinnamaldehyde content is slightly lower in Cinnamon Cinnamomum zeylanicum, ie it is about 60-75% of the volatile oil content [aka ‘essential oil’]. So for readers wanting to utilise a spice to lower the GI of a dish, and wanting to avoid any of the alleged risks associated with ingesting Cassia, then, Cinnamon Cinnamomum zeylanicum is the better choice.

As I love Cinnamon, I am loathe to consume it at that level daily, as I don’t wish to tire of it. But should you decide to consume it at that level, then I would advise you to cease cousuming it prior to surgery, as it reduces platelet aggregability. Best advice is always to discuss it with your doctor or herbalist, prior to surgery.

Readers wanting to eat rice pudding with the lowest possible GI & GL can try other GI-lowering ingredients like brown rice, ground or crushed almonds, less sucrose, and more milk and water.

I intended to clarify this issue, but unfortunately I have had to expand the issue a bit further for clarification, and to assist you in your own enquiries.

Liane Colwell, gastronomer, chef, writer.

*As a gastronomer, I routinely examine books for their place of publication. This is critical for execution of recipes as American recipes are based on 15ml tablespoons, while the Australian Metric Standard Tablespoon is 20 mls. When American cookbooks use the term ‘Cinnamon,’ it is undoubtably Cassia, Cinnamomum cassia that they are referring to.

Anonymous said...

Re rice - it's very much in the 'this for that' category when it comes to glycemic response with rice. You need to make sure you choose one of the lower GI rices. Check www.glycemicindex.com or the Shopper's Guide to GI Values (Brand-Miller and Foster-Powell).

Anonymous said...

agree with other people-- really confusing piece in the newsletter. seems like if there's so much uncertainty about it, just leave it out.

Anonymous said...

Re avoiding (possibly) confusing or complicated issues: we believe it's better for people to be informed.

hermin said...

thanks Liane - it's great to see cinnamon from different perspectives - as a food, a herb, and a spice - what's the right type and the right amount. two thumbs up. :)

Anonymous said...

I agree with the commenters that the article (not the 'issue') was confusing.

Thanks to the commenters who attempted to bring more structure to the issue.

While I typically enjoy reading this blog, and will probably return, I do have to say that this post wasn't one of the better ones.