Cinnamon may aid blood sugar, blood pressure, and more 04/09/2020
In medieval times, people considered cinnamon a basic medicine.
When the Black Death descended on Europe in 1348, doctors at the University of Paris advised the French to boil their meat in a soup featuring two kinds of cinnamon, wine, and vinegar, to use cinnamon in their sauces, and carry incense pouches containing cinnamon, along with pepper and other spices.
Unfortunately, but unsurprisingly, the common kitchen spice couldn’t defeat the still-unidentified microbe(s) that killed millions worldwide during those dark days.
Nearly 700 years later, scientists with more reasonable expectations have been studying the potential therapeutic and preventive effects of cinnamon on chronic conditions ranging from diabetes and high blood pressure to dementia and cancer.
Is there a strong case for cinnamon supplements? Not yet. The National Center for Complementary and Integrative Health, a division of the National Institutes of Health, has concluded, “Studies done in people don’t support using cinnamon for any health condition.”
But — like many other culinary herbs and spices — cinnamon is a genuine superfood that exerts substantial anti-microbial, anti-oxidant and anti-inflammatory effects. And preliminary lab and clinical evidence suggests that cinnamon can stabilize blood sugar and blood pressure levels, and thereby help us achieve optimal health.
Here’s what the research shows about cinnamon, so far.
Diabetes: Big potential, but clinical findings are mixed
Of its possible benefits, cinnamon’s anti-diabetic effect is clearest.
Cinnamon appears to slow the breakdown of carbohydrates in the digestive tract and can stimulate cells to absorb glucose, thereby acting a bit like insulin, but more slowly and modestly. Sri Lankan (or Ceylon) cinnamon — whose scientific name is C. zeylanicum — may be most effective in that regard.
In a 2012 meta-analysis-type review of the available research, scientists probed 16 animal studies that had tested the anti-diabetic effect of Ceylon cinnamon, and concluded that it displayed a wide range of benefits — weight loss, lower blood sugar levels, higher blood levels of “good” HDL cholesterol and circulating insulin, and protection against diabetes-related pain and kidney damage.
However, the results of human clinical trials have been uneven. In a 2019 meta-analysis of the most current research (18 studies in all), a team in Iran concluded that supplements lowered fasting blood sugar by 19.26 mg/dL, on average. That’s close to the drop needed to push someone at the baseline for diabetes, 126 mg/dL, to the top of the normal range, 100 mg/dL. But supplements didn’t lower HbA1C, a key measure of blood sugar averaged over three months. And they concluded that supplemental cinnamon didn’t change insulin levels or insulin resistance.
Again in 2019, another team reported a similar result. Both teams noted that the results of the various studies pooled were all over the map. Part of the problem may be that they evaluated different kinds of cinnamon.
At this point it wouldn't be wise to ditch prescribed diabetes drugs and expect to get similar benefits from a cinnamon supplement.
High blood pressure: Another promising use backed by preliminary clinical evidence
Traditional Chinese herbal medicine uses Cassia, the form of cinnamon common in that part of East Asia, to treat heart disease. And modern research on two of Cassia’s constituent chemicals showed they improved measures of heart function in rats.
There are several ways that cinnamon may improve blood pressure. Studies in dogs and guinea pigs showed that cinnamaldehye — which occurs at high levels in the essential oil extracted from cinnamon bark, particularly Cassia bark — dilated and relaxed blood vessels by altering the action of calcium channels.
And 2019 meta-analysis covering nine human clinical trials — involving 641 participants — found that cinnamon supplements significantly lowered both systolic and diastolic blood pressure, especially in trials that lasted more than 12 weeks and involved adults older than 50.
Dementia: Animal studies show effects on brain markers
Scientists have begun to think of Alzheimer’s, the most common kind of dementia, as “Type 3 diabetes,” which suggests that if cinnamon has positive effects on blood sugar, it could aid brain function as well. There is early test tube and animal evidence that cinnamaldehye can slow the growth of the tell-tale Alzheimer’s markers tau proteins and amyloid plaques.
Cancer: Cinnamon shows some potential in lab studies
Many anti-cancer drugs are based on plants or the insight they give us. When a 2020 study tested the effect of sixteen commercial essential oils from plants on human breast cancer cells, leukemia cells and cells of neuroblastoma (which usually affects small children) the team concluded that cinnamaldehyde and L.Cubeba, a traditional Chinese medicine, were most active and “could be promising as an anticancer agent.”
Cinnamon may have the power to starve a tumor of oxygen. Rapid growth requires an uptick in oxygen-bearing blood vessels to feed it. These are triggered by a chemical called vascular-endothelial-growth-factor (VEGF). So, cancer medications have been approved that suppress VEGF, although they tend to cause high blood pressure and bleeding. Cinnamon may bring a gentler alternative. Cinnamaldehyde has blocked VEGF and the growth of human ovarian cells that had been implanted in mice.
Cells grow and die in our bodies continuously. With cancer, there is growth of cells that you don't need, while other cells are unable to die. Cinnamon may fight cancer by affecting both cell growth and death, a 2019 research survey published in the European Journal of Medicinal Chemistry concluded. For example, cinnamon extract injected into melanoma tumor cells — and into mice with melanoma — induced helpful cell death. The survey team noted helpful effects on breast, lung, colon, prostate, cervical, ovarian, skin and kidney cancer, and leukemia.
Fighting infection and spoilage:
Although they didn’t have our concept of bacteria, Medieval Europeans used cinnamon to help preserve food. And they were onto something, based on the results of a recent study showing that cinnamaldehyde could help prevent spoilage in fish.
Cinnamon extract has also been shown to inhibit the growth of E. coli and affected Clostridium difficile — which is becoming a real problem in hospitals — and Candida albicans, a fungus that causes yeast infections in people. Cinnamaldehyde is used in insecticides and fungicides.
If you do decide to take a supplement, look to see what type of cinnamon it contains and don’t go overboard. Cassia cinnamon is less expensive and found in common supplements, but contains a chemical, coumarin, which can damage the liver. In Germany, the government has set the safe daily dose at .1 per kilogram — or a bit over 6 milligrams — for a 140-pound woman. A teaspoon of non-Ceylon cinnamon might have anywhere from 7 to 18 milligrams.
This morning, I put Ceylon cinnamon on my cereal as I prepared for a day at home, at my computer and following the news of the coronavirus. Interestingly, the Black Death may not have been bubonic plague — which is caused by a bacteria — but a viral disease . History repeats. Cinnamon didn’t stop Black Death, but the antioxidant-rich aromatic spice may help support optimal health and lead to useful medications that improve lives, lifting the spice to the lofty status it enjoyed when kings and queens ruled from castles.
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