Cinnamon has been used since remote antiquity as a spice, a food preservative and a medicine. The kind we usually buy is Cassia Cinnamon - the bark of a tree grown mainly in China and Indonesia. Cinnamon from Sri Lanka – so called Ceylon Cinnamon, is more expensive; it is prized for its flavor and its low content of a substance called coumarin. Coumarin is a fragrant chemical compound found in many plants. In high doses it may be toxic to the liver, and may have anticoagulant properties. Cassia cinnamon has more coumarin, while Ceylon cinnamon has very little. This is not a problem for most people, using cinnamon as a flavoring in the kitchen. People with liver disease or on anticogulants should not use large amounts of Cassia cinnamon as a medicine.
Colorectal Cancer – in mice: Adding cinnamaldehyde, the compound that gives cinnamon its distinctive flavor and smell, to the diet of mice, scientists at the University of Arizona found that mice were protected against colorectal cancer. In response to cinnamaldehyde, the animals' cells acquired the ability to protect themselves against exposure to a carcinogen through detoxification and repair. The study appeared in Cancer Prevention Research in 2015.
The next step in the research is to test whether cinnamon, as opposed to cinnamaldehyde, prevents cancer using this same cancer model. Human studies have not been reported
Polycystic Ovary Syndrome: Women with this problem have enlarged ovaries with multiple cysts, infrequent menstrual periods, excess hair growth and sometimes obesity. Previous research has shown that the use of cinnamon can reduce insulin resistance in women with PCOS. Researchers from Columbia University enrolled 45 women with PCOS into a 6 month trial; those who received cinnamon had more regular menstrual cycles than women who were given placebo. The cinnamon group had 3.82 menstrual cycles during the 6 month trial, while women in the control group only had 2.2 cycles. Two of the women in the treatment group reported spontaneous pregnancies during the trial. "Though small, this rather elegant study shows that cinnamon may be an effective and inexpensive treatment for PCOS patients," said Steven T. Nakajima, MD, President of the Society for Reproductive Endocrinology and Infertility. He is currently at Stanford.
Parkinson’s Disease – Study in mice: Scientist at Rush University Medical Center used cinnamon to treat the brain changes in mice with Parkinson’s disease (Journal of Neuroimmune Pharmacology, 2014). The study, supported by grants from National Institutes of Health, found that after oral feeding, ground Ceylon cinnamon was metabolized into sodium benzoate, which entered the brain, stopped the loss of important neurons, normalized neurotransmitter levels, and improved motor functions in mice with PD. The researchers hope to translate their findings into human studies.
Cinnamon in type 2 Diabetes: Cinnamon has been said to lower blood sugar levels, but studies showing this effect have been small, with conflicting results. Researchers at the College of Pharmacy, Western University of Health Sciences, looked at all published studies in a systematic review of cinnamon’s effect on blood sugar and lipid levels. They found that the consumption of cinnamon in various trials resulted in a statistically significant decrease in levels of fasting plasma glucose, total cholesterol, LDL-C, and triglyceride levels, and an increase in HDL-C levels; however, no significant effect on hemoglobin A1c was found. They concluded that the variability found in these studies may limit the ability to apply these results to patient care, because the preferred dose and duration of therapy are unclear.
Writing this column made me want to investigate the properties of Ceylon cinnamon. It is available for about $15 on the internet – for ½ pound, which should last a long time. You can find 2 ounces for less than $5. Whichever kind you use, think of the long past history of this spice –Egyptians used it for enbalming in 2000 BCE; Nero burned it on the pyre of his second wife to atone for his role in her death; Arab traders brought it to Europe, Portuguese and Dutch traders fought over Ceylon.
Sadja Greenwood MD, MPH - back issues on this blog