Anti-diabetic and antioxidant effect of cinnamon in poorly controlled type-2 diabetic Iraqi patients: A randomized, placebo-controlled clinical trial

AIM: To determine the effect of cinnamon on fasting blood glucose, hemoglobin (Hb) A1c, and oxidative stress markers in poorly controlled type 2 diabetes. PATIENTS AND METHODS: A total of 25 type 2 diabetic patients of both sexes, aged 49.1 ± 6.0, treated only with hypoglycemic agent sulfonylurea (glibenclamide) were randomly assigned to receive either 1 g of cinnamon or placebo daily for 12 weeks. RESULTS: A highly significant (P ≤ 0.001) reduction (10.12%) of fasting blood glucose level after 6 and 12 weeks of treatment 10.12% and 17.4%, respectively, compared to baseline value and to placebo group at corresponding duration. Meanwhile, the value of glycosylated Hb reduced in cinnamon treated group by (2.625%) and (8.25%) after 6 and 12 weeks, respectively, although this reduction was non-significant compared to baseline value. Concerning the oxidative stress markers, the level of serum glutathione showed highly significant (P ≤ 0.001) elevation after 12 weeks as compared to baseline value and placebo group at corresponding duration, malondialdehyde serum level decreased after treatment of diabetic patients with cinnamon resulted in highly significant (P ≤ 0.001) reduction after 6 and 12 weeks compared to placebo group, but when compared to baseline value, there is a (15%) reduction only after 12 weeks of treatment which was considered highly significant (P ≤ 0.001) change, Finally, administration of cinnamon to diabetic patients for 12 weeks resulted in significant (P ≤ 0.05) elevation of superoxide dismutase level. CONCLUSION: Intake of 1 g of cinnamon for 12 weeks reduces fasting blood glucose and glycosylated Hb among poorly controlled type 2 diabetes patients, as well as, there is improvement in the oxidative stress markers, indicating the beneficial effect of adjuvant cinnamon as anti-diabetic and antioxidant along with conventional medications to treat poorly controlled type 2 diabetes mellitus.