Cinnamon has a widespread reputation as a healthy spice. It has been very much appreciated for ages due to its aromatic properties, which are readily evident, but also because of ancient claims about healing powers. We don't know for sure how much of this is true, but scientists have been trying to find out.

Numerous studies using "in vitro" (experiments carried out using test tubes and biochemical approaches) and "in vivo" (using laboratory animals) have suggested that certain components of cinnamon powder have the ability to stimulate sensitivity to insulin among other promising properties. Finally, a study on human subjects was made in 2003 with encouraging results: The researchers concluded that cinnamon supplementation of 1 gram a day resulted in a 30% reduction of fasting blood glucose concentration. As a bonus, they also reported a remarkable improvement in blood profiles of triglycerides, LDL and total cholesterol. This study was promptly followed by biochemical investigations that sought to identify and characterize the molecules responsible for the observed insulin-potentiating effects with the hope of producing candidates with pharmacological applications against type 2 diabetes.

Very soon, the diabetic community experienced considerable excitement around this issue and innumerable articles, reports and opinion columns flooded the web and health magazines spreading the good news. Although doctors, pharmacists and researchers advised caution before definitive claims about beneficial effects of cinnamon were made, cinnamon extracts and cooking recipes were presented as the new panacea for diabetics.

New studies, new questions

In 2006, two new studies intended to evaluate the effect of cinnamon extracts on fasting glucose and lipid profiles were published. In the first one, published in the April issue of the Journal of Nutrition the researchers administered a dose equivalent to 1.5 grams of cinnamon to 25 post-menopausal type 2 diabetics during 6 weeks. In contrast with the previous study, no effects on insulin sensitivity or oral glucose tolerance were found. Likewise, the blood lipid profile of fasting patients did not change after cinnamon administration.

The second study, appeared in the May issue of the European Journal of Clinical Investigation involved 79 type 2 diabetes patients during 4 months and in this case, the daily dose of cinnamon water-soluble extracts was equivalent to 3 grams of powder. The levels of HbA1c and blood lipids did not improve, but there was a slight reduction in fasting glucose levels: 10.3% compared to 3.4% in the placebo group.

What is the conclusion?

Establishing whether cinnamon has components with insulin-like activity is a complex task, and a few studies are just the beginning. So far, there is evidence for a positive effect, at least in certain people and in certain conditions, but the second and third studies suggest that this cannot be generalized. The exact nature of a potential relationship between cinnamon and diabetes still needs to be addressed.

As always, cinnamon can still be used as a spice in reasonable quantities, but if you want to use large amounts of it, better go for water-soluble extracts. Pure cinnamon may contain fat-soluble compounds that, if ingested in excess, may result toxic. Of course, you need to talk with your doctor in any case.

So for the time being let us keep controlling blood sugar as usual and follow a healthy diabetic diet. Hopefully we will hear good news about cinnamon in a near future.