Effect of cinnamon supplementation on blood pressure and anthropometric parameters in patients with type 2 diabetes: A systematic review and meta-analysis of clinical trials

Cinnamon for Metabolic Diseases and Their Cardiovascular and Hepatic Complications: A Mechanistic Review

Cinnamon is one of the world's oldest and most popular spices, and is derived from the inner bark of several tree species from the genus Cinnamomum. During the last two decades, cinnamon has demonstrated beneficial metabolic effects not only in animal experiments but also in clinical trials. Even recent meta-analyses have shown the protective effects of cinnamon on different components of metabolic syndrome and their complications. In the last 5 years, several experimental studies have unraveled the intricate molecular mechanisms underlying the antihypertensive, antihyperglycemic, lipid-lowering, weight-lowering, and cardioprotective properties of cinnamon. This review paper will discuss how cinnamon and its active components, particularly cinnamaldehyde, suppress inflammation and oxidative stress, modulate mitochondrial dysfunction, and regulate glucose uptake, insulin resistance, lipogenesis, beta-oxidation, Ca2+ signaling, and other cellar events at the molecular level. Specifically, we will delve into the molecular mechanisms involved in the metabolic effects of cinnamon to provide a deeper insight into how cinnamon can bring such beneficial effects. This review hopes to encourage the use of cinnamon in clinical settings, guide the combination of cinnamon with other drugs used to treat different components of metabolic syndrome based on their mechanism of action, and support the concept of complementary medicine for metabolic diseases.

Cinnamon: a nutraceutical supplement for the cardiovascular system

Common therapies for cardiovascular diseases (CVDs) are associated with wide side effects. Thus, herbal medicines have been regarded due to fewer side effects, availability, cultural beliefs, and being cheap. For thousand years, herbal medicine has been used for bacterial infections, colds, coughs, and CVDs. Cinnamon bark contains phenolic compounds such as cinnamaldehyde and cinnamic acid with protective properties which can reduce the risk of cardiovascular diseases, cardiac ischemia and hypertrophy, and myocardial infarction. Furthermore, cinnamon has antioxidant and anti-inflammatory properties and exhibits beneficial effects on the complications of diabetes, obesity, hypercholesterolemia, and hypertension which cause CVDs. Although the protective effects of cinnamon on the heart have been reported in many studies, it needs more clinical studies to prove the pharmaceutical and therapeutic efficacy of cinnamon on risk factors of CVDs.

The effect of cinnamon supplementation on glycemic control in patients with type 2 diabetes or with polycystic ovary syndrome: an umbrella meta-analysis on interventional meta-analyses

BACKGROUND

Several meta-analyses reported glycemic-lowering effects of cinnamon, while others reported conflicting findings. In the present study, we aimed to perform an umbrella meta-analysis of previous interventional meta-analyses on the effects of cinnamon on glycemic control in patients with type 2 diabetes (T2D) or with polycystic ovary syndrome (PCOS).

METHODS

Relevant studies were searched in PubMed, Scopus, EMBASE, Web of Science, and Google Scholar up to June 2022. Meta-analyses of randomized clinical trials (RCTs) investigating the effects of cinnamon on glycemic indices including fasting plasma glucose (FPG), homeostatic model assessment for insulin resistance (HOMA-IR), insulin, and hemoglobin A1C (HbA1c) were included. Random-effects models were used to perform the umbrella meta-analysis and pool the weighted mean difference (WMD) or standardized mean difference (SMD) and their 95% confidence intervals (CI).

RESULTS

Overall, 11 meta-analyses of RCTs were included. Cinnamon supplementation was effective in reducing serum FPG (WMD: -10.93 mg/dL; 95%CI: -16.22, -5.65; SMD: -0.86; 95%CI: -1.19, -0.52), insulin (WMD: -2.01 IU/mL; 95%CI: -3.96, -0.07; SMD: -0.61; 95%CI: -0.93, -0.30), HOMA-IR levels (WMD: -0.61; 95%CI: -0.91, -0.31; SMD: -0.78; 95%CI: -1.26, -0.30), and HbA1c (WMD: -0.10%; 95%CI: -0.17, -0.03).

CONCLUSION

Cinnamon can be used as an anti-diabetic agent and an add-on treatment to control glycemic indices among patients with T2D or PCOS.

Cinnamon: an aromatic condiment applicable to chronic kidney disease

Cinnamon, a member of the Lauraceae family, has been widely used as a spice and traditional herbal medicine for centuries and has shown beneficial effects in cardiovascular disease, obesity, and diabetes. However, its effectiveness as a therapeutic intervention for chronic kidney disease (CKD) remains unproven. The bioactive compounds within cinnamon, such as cinnamaldehyde, cinnamic acid, and cinnamate, can mitigate oxidative stress, inflammation, hyperglycemia, gut dysbiosis, and dyslipidemia, which are common complications in patients with CKD. In this narrative review, we assess the mechanisms by which cinnamon may alleviate complications observed in CKD and the possible role of this spice as an additional nutritional strategy for this patient group.

Effectiveness and Safety of Ayurvedic Medicines in Type 2 Diabetes Mellitus Management: A Systematic Review and Meta-Analysis

Introduction: Many Ayurvedic medicines have the potential for managing type 2 diabetes mellitus (T2DM), with previous systematic reviews demonstrating effectiveness and safety for specific Ayurvedic medicines. However, many of the reviews need updating and none provide a comprehensive summary of all the Ayurvedic medicines evaluated for managing T2DM. Objective: The objective of this systematic review was to evaluate and synthesize evidence on the effectiveness and safety of Ayurvedic medicines for managing T2DM. Inclusion criteria: Published and unpublished RCTs assessing the effectiveness and safety of Ayurvedic medicines for managing T2DM in adults. Methods: The JBI systematic review methodology was followed. A comprehensive search of sources (including 18 electronic databases) from inception to 16 January 2021 was made. No language restrictions were applied. Data synthesis was conducted using narrative synthesis and random effects meta-analyses, where appropriate. Pooled results are reported as mean differences (MD) with 95% confidence intervals (CI). Results: Out of 32,519 records identified from the searches, 219 articles were included in the systematic review representing 199 RCTs (21,191 participants) of 98 Ayurvedic medicines. Overall, in the studies reviewed the methodology was not adequately reported, resulting in poorer methodological quality scoring. Glycated hemoglobin (HbA1c) was reduced using Aegle marmelos (L.) Corrêa (MD -1.6%; 95% CI -3 to -0.3), Boswellia serrata Roxb. (-0.5; -0.7 to -0.4), Gynostemma pentaphyllum (Thunb.) Makino (-1; -1.5 to -0.6), Momordica charantia L. (-0.3; -0.4 to -0.1), Nigella sativa L. (-0.4; -0.6 to -0.1), Plantago ovata Forssk. (-0.9; -1.4 to -0.3), Tinospora cordifolia (Willd.) Hook.f. and Thomson (-0.5; -0.6 to -0.5), Trigonella foenum-graecum L. (-0.6; -0.9 to -0.4), and Urtica dioica L. (-1.3; -2.4 to -0.2) compared to control. Similarly, fasting blood glucose (FBG) was reduced by 4-56 mg/dl for a range of Ayurvedic medicines. Very few studies assessed health-related quality of life (HRQoL). Adverse events were not reported in many studies, and if reported, these were mostly none to mild and predominately related to the gastrointestinal tract. Conclusion: The current evidence suggests the benefit of a range of Ayurvedic medicines in improving glycemic control in T2DM patients. Given the limitations of the available evidence and to strengthen the evidence base, high-quality RCTs should be conducted and reported.

Effect of Aqueous Cinnamon Extract on the Postprandial Glycemia Levels in Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial

Cinnamon is a spice used in traditional cuisine that has been investigated due to hypoglycemic properties. The objective of this study was to investigate the effect of aqueous cinnamon extract on postprandial glycemia levels in type 2 diabetes mellitus (DM2) adults. This clinical trial enrolled 36 adults with DM2, randomly allocated in two groups: the control group (n = 18) took only an oral glucose tolerance test (OGTT) and the intervention group (n = 18) took OGTT immediately followed by aqueous cinnamon extract (6 g/100 mL) ingestion. Blood glucose levels were measured on fasting and after 30, 60, 90 and 120 min in both groups. The chemical analysis of the aqueous cinnamon extract included total phenols content determination and antioxidant activity assessment through FRAP and DPPH methods. The data reveal that aqueous cinnamon extract ingestion did not show a significant difference in the incremental area under the curve (p = 0.834), maximum glucose concentration (p = 0.527) and glucose concentration variation (p = 0.873) compared with the control group. Cinnamon extract possess a total phenol content of 1554.9 mg/L gallic acid equivalent and a strong antioxidant capacity, revealed by the DPPH (5125.0 µmol Trolox/L) and FRAP (3658.8 µmol Trolox/L) tests. Aqueous cinnamon extract did not significantly influence postprandial glucose response in diabetic patients during an OGTT.

Cinnamon, an effective anti-obesity agent: Evidence from an umbrella meta-analysis

The evidence provided by meta-analyses on the beneficial impacts of cinnamon supplementation on anthropometric indices are still conflicting. Present study's aim was to evaluate the effects of cinnamon on obesity indices by an umbrella meta-analysis. The electronic databases including Web of Science, PubMed, EMBASE, Scopus were systematically searched up to March 2021. Data for the effects of cinnamon on anthropometric indices were collected from the meta-analyses. An umbrella meta-analysis was carried out using a random-effects model. The pooled effects of 7 meta-analyses showed that cinnamon supplementation significantly reduced body weight (ES: -0.67 kg; 95% CI: -0.99, -0.35, p ˂ .001), body mass index (ES: -0.45 kg/m² ; 95% CI: -0.57, -0.33, p ˂ .001) in comparison to control group. However, the effects of cinnamon on waist circumference (ES: -1.05 cm; 95% CI: -2.26, 0.15, p = .087) were not considerable. According to results, cinnamon could be suggested as a complementary weight loss agent. Favorable results were obtained at a dose of ≥3 g/day. In this study, a comprehensive study was performed on meta-analyses performed on the effect of cinnamon on anthropometric indices. This study could be considered as a final conclusion about the effect of cinnamon on anthropometric indices. The results of this study showed that supplementation with cinnamon significantly reduces BMI and body weight. The impacts were greater in doses of ≥3 g/day and in PCOS patients. PRACTICAL APPLICATIONS: In this study, a comprehensive study was performed on meta-analyses performed on the effect of cinnamon on anthropometric indices. This study could be considered as a final conclusion about the effect of cinnamon on anthropometric indices. The results of this study showed that supplementation with cinnamon significantly reduces BMI and body weight. The impacts were greater in doses of ≥3 g/day and in PCOS patients.

Some Common Medicinal Plants with Antidiabetic Activity, Known and Available in Europe (A Mini-Review)

Diabetes is a metabolic disease that affected 9.3% of adults worldwide in 2019. Its co-occurrence is suspected to increase mortality from COVID-19. The treatment of diabetes is mainly based on the long-term use of pharmacological agents, often expensive and causing unpleasant side effects. There is an alarming increase in the number of pharmaceuticals taken in Europe. The aim of this paper is to concisely collect information concerning the few antidiabetic or hypoglycaemic raw plant materials that are present in the consciousness of Europeans and relatively easily accessible to them on the market and sometimes even grown on European plantations. The following raw materials are discussed in this mini-review: Morus alba L., Cinnamomum zeylanicum J.Presl, Trigonella foenum-graecum L., Phaseolus vulgaris L., Zingiber officinale Rosc., and Panax ginseng C.A.Meyer in terms of scientifically tested antidiabetic activity and the presence of characteristic biologically active compounds and their specific properties, including antioxidant properties. The characteristics of these raw materials are based on in vitro as well as in vivo studies: on animals and in clinical studies. In addition, for each plant, the possibility to use certain morphological elements in the light of EFSA legislation is given.

The Impact of Addition Oats (Avena sativa) and Cinnamon on Cookies and their Biological Effects on Rats Treated with Cirrhosis by CCL4

Oats are represented an important source for nutrition, and it have attracted a lot of attention in recent years. In this study we produced oatmeal cookies and oats was added to formula wheat by 50% and 75%. Also, we added cinnamon to treatments 3 and 4 by 5% to increase nutrition value of oatmeal cookies, improvement sensory evaluation and increase antioxidant properties. All the cookies treatments were storage at room temperature. The purposes of this study were to study antioxidant activity for oats and cinnamon. Also determined the chemical composition include (moisture content, protein, ash, total lipids, crude fibers, carbohydrates and total calories) for oats, white flour and oatmeal cookies treatments. In addition evaluated all of sensory evaluation contain (appearance, color, texture, taste and odor) and microbiological evaluation such as (total bacterial count, spore forming bacteria and mold and yeasts count) for oatmeal cookies treatments. Also, biological assays were preformed to measure level of GPT, GOT, urea, creatinine, total cholesterol, triglycerides, HDL, LDL, and glucose. Furthermore, histopathological examination of both liver and kidneys was analyzed. The obtained results were clarified that the antioxidant activity for oats and cinnamon were 52.91% and 87.91%. Moreover, addition of oats and cinnamon to the cookies improve sensory evaluation as made it more acceptable, decreasing microbial load principally treatments 4 (prepared by 75% oats + 5% cinnamon). Biochemical assays were improved in rats with cirrhosis of carbon tetrachloride and their histopathological examination of liver and kidneys. It was clear that the additions ground whole grain oats and cinnamon to wheat flour based cookies improve its nutritional, chemical, and biological functions properties.

Effect of cinnamon on blood sugar and anthropometric measurement in type two diabetes patients

There is some emerging evidence that suggests certain supplements help lower blood sugar levels. One of these is cinnamon, which exhibits characteristics that mimic insulin, such as the activity of biologically active substances to activate insulin receptor kinase, increasing glucose uptake, autophosphorylation of the insulin receptor, and glycogen synthase activity. To assess the effect of the cinnamon substance on lowering fasting blood sugar, modifying body weight, body mass index (B.M.I.), and waist circumference in type two diabetics. A randomized controlled intervention clinical trial. The study was conducted on 60 patients with type II diabetes mellitus; the study followed both gender patients for four weeks. The contributors were allocated randomly into a group that receives 2 g/d cinnamon substance (intervention group), and a group without cinnamon substance is given (control group). Fasting plasma glucose (F.P.G.) and anthropometrics measurement at the beginning (beforehand cinnamon supplementation and 4week at the end of the study duration). After 4 weeks of cinnamon taken, serum F.P.G. levels significantly improved (P≤0.0001). Anthropometric measurements (weight, height, B.M.I.) were reduced significantly (change mean ≤ P=0.001) for all. The Present study disclosed that supplementation of 2 gm cinnamon improves F.P.G. and has a good role in anthropometric indices (weight, waist circumference, B.M.I.).

Efficacy of Cinnamon as an Adjuvant in Reducing the Glycemic Biomarkers of Type 2 Diabetes Mellitus: A Three-Month, Randomized, Triple-Blind, Placebo-Controlled Clinical Trial

The major aim of this randomized, placebo-controlled, triple-blind clinical trial was to evaluate the efficacy of cinnamon as an adjuvant treatment in reducing glycemic levels in people with type 2 diabetes, compared to a placebo. The study was conducted between August and December 2019, with 160 people with type 2 diabetes, in five Primary Health Units, in Parnaíba, Brazil. Inclusion criteria were: persons of both genders using oral antidiabetic agents, with glycated hemoglobin ≥ 6.0%, and between 18 and 80 years of age. The primary outcome was change in glycated hemoglobin levels after 90 days of intervention. Other biomarkers evaluated were fasting blood glucose, insulin level, and HOMA-IR index. Participants were divided equally into two groups of 80 individuals each, and were given 3 g capsules of either cinnamon or placebo to be taken in combination with their usual oral antidiabetic agents. After 90 days, participants in the cinnamon group had statistically significant reductions of 0.2% of glycated hemoglobin and 0.55 mmol/L of fasting venous glucose, when compared with the placebo group. Cinnamon reduced the glycemic measures of persons with type 2 diabetes, albeit with modest reductions. TRIAL: RBR-2KKB6D.