There are two types of cinnamon, Ceylon and Cassia. Cassia is cheaper and is the one in just about every grocery store or food product. It’s also the one that contains high amounts of Coumarin, a chemical that may cause liver damage in some people. Ceylon is more expensive, but it may allow you to enjoy all the taste and benefits of cinnamon without the Coumarin.
How much is “large quantities”? I’ve found one teaspoon per day to be sufficient for flavoring.
The article says, " Ingesting too much coumarin can lead to liver damage, as recent studies on rodents have revealed." One problem often found in such claims is the definition of “too much.” Drinking too much water can dilute blood sugar and cause death (it takes more water than most people can even drink in a day). Eating too much sugar can cause diabetes (this one takes about 30 years of continuously eating too much sugar). How much of this chemical is “too much,” and how much cinnamon must one eat to get too much of this chemical? The article also says, “…moderation is key to avoid possible damaging effects to the liver when ingested.” Later, it gives a quantity, “The amount ingested in one day should not exceed a total of one teaspoon overall and certainly not straight as in the challenge.” Right after that though, it says, “Cinnamon seems to only be harmful in mass quantities.” I would not consider a teaspoon per day “mass quantities.” For a spice, I suppose mass quantities could start as low as a quarter of a cup a day. (Also, there are far more than two varieties of cinnamon. Cassia is indeed the most commonly found cinnamon in the U.S., but the other varieties are often extremely hard to find, not to mention the much higher expense.)
I recently did a lot of research on cinnamon. About twice the amount suggested in the article is sufficient to maintain a significant reduction in blood sugar. Cinnamon improves the ability of cells to take in glucose, which can improve the symptoms of type 2 diabetes (ironically, it can also help hypoglycemia and hyperglycemia both). It has been used for this in South America for centuries. So, as usual, there is a trade off. In my research, I did find mention that excessive cinnamon intake could cause liver damage (none of the participants in the studies developed problems, and at least one study was feeding a group around 3 teaspoons a day for over a month), but I found no studies that gave a specific maximum intake for humans (all studies on liver damage were conducted on rats).
I do have one question: Do you have any more sources? The article linked to does not cite any sources, and it is not a scientific journal, so it cannot be a primary source. I am always skeptical of sources that make bold claims like this without any evidence to back the claims up. (I am also curious if anyone studied this using actual cinnamon, or if they all used the chemical in a pure form. Frequently, potentially harmful chemicals in food react with other chemicals in the same food during digestion to neutralize each other. Ironically, it goes the other way as well. Sodium benzoate, a common preservative in soda, and ascorbic acid, also found in many sodas, react in the stomach to form benzene, which is carcinogenic.)
Anyhow, it would probably be more accurate to say that large intake of cinnamon could cause liver damage. The evidence that it actually does is pretty weak.
Thanks for the well-informed response. I saw a post where one guy said he was using 4 teaspoons per day in his soylent. It seemed a cautionary blurb was in order because a lot of us are going to be using Soylent/soylent as a primary nutrition source, daily, for a long time. We’re all adults and can make informed choices. However, I did change the title of the post, as suggested. Don’t want to seem like some alarmist, you know.
Nice! Just for the record, I am not trying to debunk the possibility that excessive cinnamon causes liver damage. It is entirely possible. The evidence supporting that claim is currently fairly weak though. For people that are using large amounts of cinnamon in their soylent, I would highly recommend researching this periodically. I would not advocate changing your recipe based on this weak evidence though. Cinnamon has some benefits that are fairly well proven. If you need those benefits (for instance, the blood sugar thing), it is probably worth the risk. Just make sure you stay informed.
So far as the 4 teaspoons per day, while I would be mildly skeptical of the potential for liver damage with that amount, I do not think it is beneficial to take that much. In my research on the blood sugar thing, the only difference found between one teaspoon per day and three a day was how fast the effects manifested. For one teaspoon, it took about a month for the full blood sugar reduction. For three I believe it took around half that. The actual end reduction was the same for both (and for all amounts it went away within about 15 days of eliminating the cinnamon from the diet). Given this, I would suggest that the safest solution would be to include about one teaspoon of cinnamon per day. This is enough for the full blood sugar benefits (with a bit more time before the full benefits are seen), but it also minimizes any risk for liver damage. (On a side note, stevia sweeteners have a similar effect on blood sugar, through different mechanisms. Especially do not overdo this one, but you probably could add one packet to a day’s mixture to further improve blood sugar. Keep an eye on research for this one as well, as it is not as well understood as the cinnamon.) And, if you need the cinnamon to fill a nutrient requirement, most spices are high in the same nutrients. You could probably replace part of the cinnamon with something else. (I believe cloves has a similar nutritional profile and basil also does with a lot more vitamin K, which can be hard to find in natural ingredients. The herbs I have used in my recipes include basil, cinnamon, ginger, parsley, and turmeric. I do not recall the nutritional profiles of all of those, but they are all pretty cheap and nutritional data is easy to find for all of them.)
Note that many spices have potentially harmful chemicals (in fact, most foods seem to). The best strategy is to have a lot of variety. For very high nutrition foods (spices and herbs tend to fit here), small amounts of several types is better than a large amount of just one. Lower nutrition foods that are designed to provide carbs, fats, or protein are more forgiving, but greater variety is still wise. With a normal diet, this is accomplished by having different foods with each meal. With soylent, it requires some deliberate thought to have a good variety, because most people would prefer to use one recipe all the time (in fact, that is part of the point).
Relevant thread. The coumarin may also have benefits in certain contexts, which may be related to its blood thinning effects. It’s never been studied as part of a diet with a constant influx of it, and many studies don’t bother distinguishing between ceylon and cassia.
I tried cinnamon in my soylent for the first time this morning. It was awesome! I think you’ve got me convinced.
I suspect that cinnamon may also act as a flavor enhancer (kind of like salt, though a totally different flavor). When I started adding it to my soylent, the flavor improved dramatically, even though the cinnamon was the only difference.
On a side note, I read about a study where it was found that smelling cinnamon before or during a test, test takers would score higher on average than a control group without the cinnamon. The study looked legitimate, but I did not check to see if there are any confirming studies. I figure, it can’t hurt, and I like the smell of cinnamon, so why not?
I added cinnamon to my variant of the People Chow recipe since my version was a little low on manganese, and 1g of cinnamon (1/2 teaspooon) solved that issue. I figured it would be a good flavoring for one of my bottles of soylent, and would help with the manganese deficiency.
Reading about the possible liver damage, I’m thinking about switching to ceylon cinnamon instead of the regular cassia cinnamon. But does ceylon cinnamon contain large amounts of manganese? The only nutritional info I’ve found has been for the standard cassia cinnamon. Anyone have any luck?
My wife says she is now going to take some cinnamon to whiff before her CLEP test on Monday
There are lots of things that are high in manganese you could use. Most spices/herbs contain significant amounts (in fact, this has become somewhat of a problem for me, because oat flour is high in it as well, which has made it hard to avoid getting too much). That said, I would not worry about liver problems from 1/2 a teaspoon of cinnamon a day. Given the amounts they had to feed rats to see liver damage (so far there is no other evidence that humans are susceptible to liver damage from excessive cinnamon), I would estimate that it would take at least 1/4 of a cup or more per day to cause problems (see my previous posts for a bit more information; there have been other studies of cinnamon that did involve humans, none of which discovered any negative side effects from much larger amounts than you are using).
Good luck to her! I don’t know if it actually works, but it’s not like it costs anything to do. Besides, I particularly like the smell of cinnamon, so even if it does not work, I think it is still worth doing. (I once suggested to an employee of the testing center at the college I am attending that they pipe in cinnamon scent into the ventilation, to potentially improve test scores. I don’t know if she took the suggestion seriously though.)
EU agencies say that 0.1mg/kg is ‘too much’. For an average 150# person that is about 7 grams/day. The article goes on to say that this is based on animal studies and that humans are likely to be less sensitive. Then it also says that some people may be hypersensitive but that the 0.1mg/kg limit is still safe.
I’m thinking that a compromise would be to mix the two types so that you’d have the flavor and low cost with an added safety margin.