Millions of American adults have prediabetes. The CDC defines this as having fasting blood sugar over 100 but less than 126 mg/dL, the cut-off for a diagnosis of diabetes. Learning that you have prediabetes can be alarming, but it offers an opportunity to make changes that will reverse the condition and prevent full-blown diabetes. Regular physical activity and a high-nutrient, low-energy diet are central to this effort. Spices and condiments may also contribute to blood sugar control, so you may want to learn about the pros and cons of cinnamon. Many readers like to use it to lower their blood sugar, but new data shows that many brands of cinnamon are contaminated with lead.
A Study of Cinnamon for Blood Sugar:
A new study has tested the effect of daily cinnamon spice supplementation on blood glucose levels (American Journal of Public Health, March, 2024). The 18 overweight volunteers were diagnosed with prediabetes. In this double-blind randomized clinical trial, participants got 4 grams of Indonesian cinnamon or placebo for a month. After a two-week washout period, they then received the other intervention.
The authors report that cinnamon lowered blood sugar relative to placebo and was well tolerated. They describe the 4-gram dose as equivalent in size to a typical sugar packet.
In summary, they write:
“Cinnamon, a widely available and low-cost supplement, may contribute to better glucose control when added to the diet in people who have obesity-related prediabetes.”
What Are the Pros and Cons of Cinnamon?
Q. My blood sugar was 101. I did some reading on the internet and found out that I might be able to reduce it by taking cinnamon.
Every morning, I put less than a teaspoon in my coffee. After a month my blood sugar, cholesterol and triglycerides all went into the normal range. My blood sugar is now 81.
Pros of Cinnamon:
A. Cinnamon can help lower blood sugar, according to a recent meta-analysis (Diabetes Research and Clinical Practice, online Aug. 16, 2019). Scientists studying rats demonstrated that a water-based extract of cinnamon paired with high-intensity exercise can reverse metabolic syndrome (Nutrition, Sep. 2019). In addition, this spice has intriguing anti-cancer activity (European Journal of Medicinal Chemistry, Sep. 15, 2019).
Cons of Cinnamon:
There could be negative effects from regular cinnamon consumption, however. Cassia cinnamon contains coumarin, which can damage the liver. The amounts of this compound are variable, and Ceylon cinnamon (Cinnamomum zeylonicum) does not have any coumarin.
Avoiding Coumarin:
Coumarin is not water-soluble, however. Consequently, if you put ground cinnamon in your disposable coffee filter rather than directly in your coffee, you get the benefits from cinnamon without the danger of coumarin. Don’t try this in a reusable filter; ground cinnamon can create a gummy mess.
Lead in Cinnamon:
A terrible scandal in fall of 2023 involved unacceptably high levels of lead in cinnamon-flavored applesauce pouches designed for children. The FDA investigated and three brands were eventually recalled, but not until too many children had suffered from lead poisoning. The agency determined that the cinnamon in the pouches was the source of the lead.
Now, the FDA is warning consumers of elevated lead levels in six brands of ground cinnamon. Lead levels in these spices are not as high as in the contaminated applesauce, but people could still experience harm if they used the spices over an extended time. If you have any of the following brands of cinnamon in your spice rack or drawer, you should discard it: El Chilar, La Fiesta, Marcum, MK, Swad and Supreme Tradition. Discount or low-price stores are the principal merchants for these brands. Here is a link to the FDA’s list of contaminated lots.
If you haven’t bought any of these brands, but you wonder if the brand of cinnamon in your own spice rack is contaminated, you could check ConsumerLab.com. This company tests many spices and almost always looks for lead and arsenic contamination. Its cinnamon analyses also include coumarin levels. There is a subscription fee for the information.
Update on Lead in Cinnamon:
In 2024, the independent testing organization Consumer Reports has found high levels of lead, above 1 ppm, in a dozen brands of cinnamon (Consumer Reports, Sep. 12, 2024). That’s a third of the 36 brands it tested. The highest levels were found in Paras, EGN, Mimi’s Products and Bowl & Basket ground cinnamon. Others that had unacceptably high lead levels were Rani Brand, Zara Foods, Three Rivers, Badia and Deep.
Some brands of five-spice powder, which contains cinnamon, also had unacceptably high levels of lead. CR identified YuYee Brand, BaiLiFeng and Spicy King. Any of the products containing too much lead should be discarded rather than consumed, for safety’s sake.
Consumer Reports testers found that 365 Whole Foods Market, Morton & Bassett San Francisco and Sadaf brands contained the lowest levels of lead. James Rogers, director of product safety testing at Consumer Reports, suggests choosing spices with the lowest levels of lead, without panic. The danger is highest for young children, especially if they are consuming cinnamon frequently.
Possible Interactions:
A recent case report warns of the dangers of cinnamon interacting with oral anticoagulants (European Journal of Case Reports in Internal Medicine, online July 19, 2019). An 80-year-old man who had been taking dabigatran (Pradaxa) for atrial fibrillation started taking a solution of cinnamon and ginger. Three days later he was vomiting blood and his stool was black with blood. The doctors were unable to control his intestinal bleeding and he died. There may be other factors that contributed to this tragedy. However, to be prudent, people taking anticoagulant medicines should not use cinnamon as medicine.
Learn More:
You can learn more about using cinnamon and other natural flavoring compounds in our book, Spice Up Your Health: How Everyday Kitchen Herbs and Spices Can Lengthen & Strengthen Your Life. You may also wish to listen to our interview with Lisa Gill about Consumer Reports’ earlier findings on lead contamination of spices.
