No question, cinnamon is a versatile spice that adds flavor to baked goods, chili, desserts and more. It’s great sprinkled over oatmeal—or a cappuccino. The question is whether it has medicinal effects, as makers of cinnamon supplements claim. Their products sport such labels as “promotes sugar metabolism” or “helps maintain normal range blood sugar.” Here are some answers, gleaned from research over the past few years.
For blood sugar. Scientists have isolated substances in cinnamon that help control blood sugar. Antioxidants (polyphenols) in cinnamon may also be beneficial. A small study in the Journal of the Academy of Nutrition and Dietetics in 2012 found that cinnamon (added to farina cereal) modified the normal increase in blood sugar in both obese and normal-weight people. And in a small study in the International Journal of Preventive Medicine in 2012, people with type 2 diabetes who took a cinnamon supplement for eight weeks had reductions in fasting blood sugar and hemoglobin A1c (HbA1c, a measure of long-term blood sugar control).
On the other hand, a study in Cardiovascular Diabetology in 2011 found that adding cinnamon to a high-fat meal had no effect on blood sugar (or blood cholesterol or other variables) in a small group of healthy people. And a 2012 Cochrane Collaboration review of 10 studies involving 577 people with diabetes concluded that cinnamon was no better than a placebo in reducing blood sugar and HbA1c.
For blood pressure. According to an analysis of three well-designed studies, published in the journal Nutrition in 2013, cinnamon can lower blood pressure in people with both prediabetes and diabetes (about five points systolic, three points diastolic, on average), at least in the short term. The paper concluded that cinnamon looks “hopeful” for blood pressure, but it also noted that studies over the years have had inconsistencies and that the evidence is still too limited to recommend its use. There’s also no clear explanation how cinnamon may help blood pressure.
Cinnamon unknowns. Studies have had conflicting results, possibly because they have used different types of cinnamon, as well as different forms and doses. Plus, participants have varied in initial blood sugar levels, body weight, medications and other variables. Some have had full-blown diabetes, others just different degrees of insulin resistance—and some were healthy. It’s not even clear whether the polyphenols in cinnamon are well absorbed by the body. What’s more, if cinnamon does have some medicinal benefits, studies haven’t lasted long enough to know if they persist over time.
Bottom line: There’s no harm— and possible benefit—in adding cinnamon to foods. But the evidence is too preliminary for us to recommend supplements. No one knows what an effective dose would be, and many are just ground cinnamon sold in expensive capsules; others are concentrated extracts. In low or moderate doses, they are unlikely to have adverse effects, but if you have diabetes or other medical conditions, tell your doctor if you do try them. Be aware that some cinnamon supplements also contain other ingredients of even more questionable value.