Q: You recently wrote about cinnamon in your column and mentioned coumarin in cassia cinnamon. You said Ceylon cinnamon doesn’t contain this hazardous compound.
Do cassia cinnamon and Ceylon cinnamon taste the same? (I believe you said cinnamon on supermarket spice shelves is cassia.)
A: You are right that most cinnamon in supermarkets is the less-expensive cassia cinnamon. It may contain coumarin, which might damage the liver at high doses. That’s why we don’t recommend people take supermarket cinnamon on a regular basis, except as a water extract. Using it to flavor food is not a concern.
Cassia cinnamon and Ceylon cinnamon have slightly different flavors. Cassia is “hotter,” and Ceylon is more complex. Ceylon cinnamon does not contain significant coumarin, but more studies on the benefits of cinnamon for controlling blood sugar and lowering cholesterol have used cassia cinnamon. The two types are derived from the bark of related tree species.
A recent review of research shows that either type of cinnamon may offer some modest improvement of blood-sugar control in addition to regular diabetes treatment (Journal of the Academy of Nutrition and Dietetics, November 2016).
Q: I struggled with angular cheilitis for 60 years, from the time I was 5 until two years ago. Then my family doctor tested my vitamin D level, and the result came back showing I was highly deficient with a score of 12.
He had me start taking 2,000 IU of the vitamin daily. The first thing I noticed was that the corners of my mouth were no longer cracking and sore or bleeding. Since then, I have continued to take 2,000 IUs and have had a flare-up only once, when I was traveling and neglected to take my pills.
I mentioned the connection between vitamin D and angular cheilitis on a recent visit to a dermatologist. He dismissed what I told him, saying it was rare for vitamin D to help something like this. Perhaps I am a rare bird, but I swear that taking vitamin D has healed what was a lifelong problem for me.
A: Your vitamin D story is fascinating. It does not appear that doctors have studied the effect of vitamin D supplementation on angular cheilitis (cracks at the corners of the mouth). It may be brought on by nutritional deficiencies (low levels of B vitamins or minerals like zinc and iron). This painful condition is more commonly treated with antifungal or antibacterial medication.
Others who would like to learn more about inadequate vitamin D and its potential symptoms may be interested in our Guide to Vitamin D Deficiency. Anyone who would like a copy, please send $3 in check or money order with a long (No. 10), stamped (68 cents), self-addressed envelope to: Graedons’ People’s Pharmacy, No. D-23, P.O. Box 52027, Durham, NC 27717-2027. It also can be downloaded for $2 from our website: www.peoplespharmacy.com.
Q: Olive leaf extract seems to lower high blood pressure and have antibacterial and antifungal qualities. Is it safe to take?
A: Preliminary research in animals and humans suggests that olive leaf extract may indeed lower blood pressure (Nutricion Hospitalaria, July 2015; Journal of Medicinal Food, May 2016).
There has not been much research on the pros and cons of this dietary supplement. One case report suggests that olive leaf extract might cause irritability and other psychological side effects (New Zealand Medical Journal, April 1, 2016).
In their column, Joe and Teresa Graedon answer letters from readers. Email them via PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”