Take Cinnamon for Diabetes?

Summarized by Robert W. Griffith, MD
February 27, 2004

Introduction

People with type 2 diabetes are 2-4 times more likely to get cardiovascular disease, associated with abnormal lipid levels. So something in the diet that could help normalize blood glucose AND blood lipid levels would clearly get considerable attention. Some traditional plant medicines, culinary herbs, and spices have been found to lower blood glucose levels by enhancing insulin's activity, and animal studies have shown beneficial effects of certain herbs on lipid levels. Now a clinical study of cinnamon in type 2 diabetics has been published in Diabetes Care.

What was done

This study was done in Peshawar, Pakistan, on 60 people with type 2 diabetes. They had to be over 40, not taking insulin, and with a fasting blood glucose level between 140 and 400 mg/dL (7.8-22.2 mmol/L). There were 30 men and 30 women of average age 52, who had had diabetes for at least 4 years.

The 60 patients were randomly assigned to one of 6 groups. Cinnamon was available in capsules containing 500 milligrams. Placebo (dummy) capsules contained 500 mg of wheat flour. Groups 1, 2, and 3 received 2, 6, or 12 cinnamon capsules daily, while groups 4, 5, and 6 received 2, 6, or 12 placebo capsules, respectively. Capsules were taken after meals, with water, for 40 days. Normal meals and usual medication was continued throughout the study.

Blood levels of glucose, triglycerides, LDL-cholesterol, HDL-cholesterol, and total cholesterol were determined at baseline and on days 20, 40, and 60 (i.e. 20 days after the end of cinnamon intake).

What was found

After 40 days, all three 'dose levels' of cinnamon reduced fasting blood glucose levels, in mg/dL, as follows:

It can be seen that daily cinnamon, whatever the amount given, caused a significant reduction in fasting glucose levels after 40 days, which persisted, to a considerable extent, even 20 days after the cinnamon was stopped. Placebo had no such action.

A similar effect was seen on the average LDL-cholesterol levels (given in mg/dL):

Serum triglycerides and total cholesterol levels were also affected by cinnamon in this beneficial way. HDL-cholesterol, on the other hand, showed no cinnamon-induced changes. The placebo groups showed no changes, either.

Comment

The findings of this study are clear. One to six grams of cinnamon, daily for 40 days, reduces fasting blood glucose by 18-29%, triglycerides by 23-30%, LDL-cholesterol by 7-27%, and total cholesterol by 12-26%. There was no 'dose-effect'; thus it's not known if less than 1 gram a day would be equally beneficial. The changes persisted, largely, for 20 days after the patients had stopped taking extra cinnamon.

How does cinnamon work in this way? That remains to be determined. It's likely that somehow there's an increased sensitivity to insulin. And cinnamon also has antioxidant properties.

One of the co-authors of this report, Dr Richard Anderson of the Human Nutrition Research Center, Beltsville, USA, has stated "I don't know of anything else that can change glucose, triglycerides and cholesterol levels nearly so much". Such an impressive study result must clearly be confirmed in additional trials before widespread use of cinnamon by type 2 diabetics can be promoted. However, a cinnamon bun or pastry may now be devoured with a lower sense of guilt than previously . . . .

Source

• Cinnamon improves glucose and lipids of people with type 2 diabetes. A. Kahn, M. Safdar, MM. Ali Kahn,  et al., Diabetes Care, 2003, vol. 26, pp. 3215--3218

Related Links
Nutrition in Type 2 Diabetes
How Diabetics Should Avoid Serious Cardiac Events
Combat Diabetes Risk Factors