A new review conducted by Pauline J. Maddox at Southern Adventist University suggests that taking cinnamon may help type 2 diabetes mellitus.

The author reviewed a total of 15 trials with 10 studying the effect of cinnamon on HbA1c levels and 13 on the fasting blood glucose (FBG).

Out of the trials, six showed that cinnamon significantly reduced HbA1c levels while 10 trials showed cinnamon lowered fasting blood glucose significantly.

The author concluded that based on the review, "cinnamon can be recommended as effective therapy for reducing HbA1c levels and FBG levels in type II diabetics."

The doses of cinnamon used in the trials ranged from one gram to six grams daily with meals.

Keep in mind that some type of cinnamon (cassia cinnamon or Cinnamomum cassia) is full of a compound called coumarin that can be toxic to the liver  when the cinnamon is used at a high dose and or for a long period.  And also cinnamon should not be used along with statins.

Type 2 diabetes mellitus is a condition in which the patient suffers insulin resistance and cannot adequately handle blood sugar.  Patients with the condition are often able to produce insulin, but endogenous insulin does not work properly in the patients.

Source: Maddox, Pauline J., "Cinnamon in the Treatment of Type II Diabetes" (2016). Graduate Research Projects. Paper 79. 

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