Type 2 Diabetes (T2D) is protected against chronic hyperglycemia. This is one of the main causes of death in the country, being a public health problem worldwide. Some studies have shown that herbal products have beneficial effects in patients with diabetes by improving the metabolism of glucose and lipids. Cinnamomum Zeylanicum (C.Z.), colloquially cinnamon, is one of the components of the diet that has active biological substances with insulin mimetic properties. In Mexico, little has been investigated about the use of this therapy. Previous studies do not conclude if there is a statistically significant effect in the glycemic control of patients with diabetes. Therefore, it is proposed to evaluate the effect of the supplement consumption of C.Z. 3 months compared to a control group on the change in glycated hemoglobin (HbA1c) in Mexican adults with T2D. This is a randomized, single-blind clinical trial with T2D patients from the clinic CAAPS . Those that are divided into: intervention group with supplement of 2g daily C.Z. Oral route (capsules) for 90 days, and control group with placebo. The figures will be recorded: HbA1c, fasting plasma glucose, blood pressure, cholesterol, HDL, LDL, triglycerides, waist circumference, weight and body mass index.

Cinnamon, in in vitro and in vivo studies, has been shown to have biologically active substances with mimetic properties of insulin. In 1990 an unidentified component of cinnamon was extracted and named as an insulin-enhancing factor. The components of cinnamon bark oil (Ceylon) contain cinnamaldehyde (75%), cinnamyl acetate (5%), caryophyllene (3.3%), linalool (2.4%) and eugenol (2.2%). It is believed that the modality in which cinnamon expresses its effect on blood glucose can be attributed to its active component cinnamaldehyde.

Within the 250 species of the Cinnamomum genus there are four types that are used as spice, the Cinnamomum Zeylanicum or Sri Lanka (also known as C. verum Ceylon) commonly referred to as "true cinnamon"; three very popular spices related to C. cassia are C. aromaticum (cinnamon china), C. loureirii (cinnamon vietnamese) and C. burmanni (cinnamon indonesia).

One important difference between "true cinnamon" and cinnamon cassia is its coumarin content. The content of coumarin in cinnamomum zeylanicum is too low to cause health risks, while the level of coumarin in Cinnamomum aromaticum appears to be much higher and may pose health risks if consumed in larger quantities and on a regular basis. The use of cinnamon cassia as a regular supplement with meals is not recommended or the daily dose has been restricted in many countries due to the toxic effects of Cinnamomum aromaticum on the liver and coagulation. In contrast, cinnamomum zeylanicum has been shown to contain a lower amount of coumarin, and therefore it may be possible to use it at higher doses without toxic effects for longer periods. In vivo studies with cinnamomum zeylanicum have not shown significant adverse effects or toxicity in liver, kidney and / or pancreas.

In a systematic review it was concluded that the evidence available in vitro and in vivo suggests that cinnamomum zeylanicum has antimicrobial, antiparasitic, anti-inflammatory and antioxidant properties. The authors also indicated that cinnamomum zeylanicum appears to lower blood glucose, serum cholesterol, and blood pressure, suggesting beneficial cardiovascular effects.

The mechanism of this hypoglycaemic action is not entirely clear, but can be attributed to an increase in serum insulin levels, storage of liver glycogen, better signaling of the insulin receptor, an insulinomimetic effect, or reduction of alpha activity intestinal -glucosidase. In clinical terms, these actions could lead to improvements in glycemic control and insulin sensitivity, and a possible reduction in the complications of diabetes.

In Mexico, little has been investigated on the use of this alternative therapy. In other countries, such as the United States, the United Kingdom, China, Pakistan and Germany, studies have been conducted on the potential effects of cinnamomum in in vitro, in vivo and in human studies. The effect of C. zeylanicum on glycemic control is inconclusive due to the contradictory results of the literature, some authors found statistically significant changes in glycosylated hemoglobin or fasting plasma glucose in randomized clinical trials compared with a placebo group. On the other hand, several authors report not having found significant changes in glucose levels in the study subjects.

In the case of the Mexican population, no scientific studies were found that address the use of cinnamomum as an alternative therapy-alone or combined-in the control of glycemic levels in patients with diabetes. Therefore, in this study we propose to evaluate the effect of cinnamomum zeylanicum supplement consumption at 3 months compared to a control group (placebo) on the change in HbA1c in Mexican adults with T2D.

Inclusion Criteria:

• Subjects with a prior medical diagnosis of T2D
• Mexican adults (> 18 years)
• Treatments only with oral hypoglycemic agents
• HbA1c >6.5% and <10%
• Attendees to two participating primary health care centers.

Exclusion Criteria:

• Patients who have an allergy to cinnamon or wheat flour.
• Treatments with insulin
• Gastrointestinal problems or any condition in cinnamon is not well tolerated or contraindicated
• Cardiovascular, hepatic or renal disease.
• Use of addictive substances as drugs.
• Pregnant or lactation
• Psychiatric condition that prevents adherence to treatment
• Use of a supplement with an effect on glucose

A simple blinding (participants blinded to the belonging group). The person who will randomize the participants will not be involved in the recruitment of participants. This will be done when we have the total sample of participants.