Cinnamon Slows Gastric Emptying, Too

Summarized by Robert W. Griffith, MD
July 31, 2007

Summary

Healthy volunteers given a test meal with added cinnamon have delayed gastric emptying as well as lower postprandial blood glucose levels.

Introduction

Cinnamon has been of interest to diabetics since 2003, when a study was published showing that taking 6 grams daily of the spice for 40 days lowers fasting glucose levels, triglycerides, and total cholesterol levels (see first Related Link below). In fact, many herbs and spices are likely to affect blood sugar levels, based on an insulin-like activity in the test tube: allspice, bay leaf, cloves, nutmeg, witch hazel, oregano, and black and green tea. Of these, cinnamon has the highest activity as well as an antioxidant effect. Now Swedish researchers have studied the possible effect of cinnamon on gastric emptying, post-meal blood sugar, and feelings of satiety. They published their findings in the American Journal of Clinical Nutrition, and we summarize them here.

What was done

The gastric emptying rate (GER) was measured employing a standardized ultrasound method on 14 healthy subjects, with and without cinnamon added to a standard meal. The measured stomach cavity area on ultrasound was used, with percentage change representing emptying. The subjects (8 men and 6 women) were aged between 20 and 38 and were healthy.

After an 8-hour fast and having blood taken for a fasting glucose level, the subjects were given test meals of 300 grams of rice pudding, with a caloric value of 330 calories. Six grams of cinnamon was added to one meal consumed, but not to the other test meal eaten; the two types of meal were taken in random order several days apart.

Blood glucose levels were measured at 15, 30, 45, 60, 90, and120 minutes after the test meals. A satiety scale was used to measure hunger, with scores ranging from minus 10 (extreme hunger) to 10 (extreme satiety). Satiety was scored before the test meal, and at each blood draw afterwards.

What was found

Eating cinnamon with the test meal led to a significantly lower blood glucose response in the postprandial phase (15, 30, and 45 minutes after the meal) than the rice pudding alone. (This finding was similar to that described in the earlier study referenced above.)

When the subjects took cinnamon their gastric emptying rate was significantly slower than when they ate without cinnamon. However, the apparent difference was slight - the percentage change in the area of the stomach cavity between 15 and 90 minutes after the meal was 34.5% with cinnamon and 37% without.

There were no significant differences in subjective feelings of fullness (satiety) after the meals with and without cinnamon.

What the findings mean

Eating 6 grams of cinnamon decreases blood glucose levels between 15 and 45 minutes after a test meal, and slows emptying of the stomach between 15 and 90 minutes after the meal. In fact, one may be partly explained by the other - slowing gastric emptying would naturally lead to a delay in the expected rise in blood glucose. However, the reduction in gastric emptying rate was less pronounced than the decrease in postprandial glucose, suggesting that cinnamon has an intrinsic effect on blood glucose - possible by stimulation of insulin receptor activity.

This result, together with earlier studies of the effect of cinnamon on blood sugar, raises the obvious question of whether the spice should be taken by diabetics. Three years ago we wrote: "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 . . . ." Since then no positive clinical studies have been reported on the use of cinnamon therapeutically; however, the occasional cinnamon pastry remains a safe (but half-hearted) way to capitalize on the findings in this study.

Source

• Effect of cinnamon on postprandial blood glucose, gastric emptying, and satiety in healthy subjects. J. Hlebowicz, G. Darwiche, O. Bjorgell, L-O. Almer , Am J Clin Nutr , 2007, vol. 85, pp. 1552--1556

Related Links
Take Cinnamon for Diabetes?
Postponing the Addition of Insulin
When Diet Is not Enough for a Type 2 Diabetic

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