Effect of cinnamon (Cinnamomum Zeylanicum) supplementation on serum C-reactive protein concentrations: A meta-analysis and systematic review

Effect of cinnamon supplementation on blood pressure, oxidative stress, and inflammatory biomarkers in adults: An umbrella review of the meta-analyses of randomized controlled trials

AIMS

Cinnamon has positive effects on markers of cardiometabolic health, including blood pressure (BP), oxidative stress, and inflammation. Despite the evidence accumulated from meta-analysis studies on the effects of cinnamon on these markers, the reported findings are still controversial. This umbrella review was conducted to evaluate the evidence and provide a definitive clarification.

DATA SYNTHESIS

We conducted a systematic search in four scientific databases, including PubMed, Scopus, Web of Science, and Embase electronic databases, up to March 2024 to identify systematic reviews and meta-analyses of randomized clinical trials investigating the impact of cinnamon on blood pressure, oxidative stress, and inflammation. The findings revealed that cinnamon might exert favorable effects on systolic blood pressure (SBP) (ES = -2.36 mmHg; 95% CI: 3.86, -1.40), diastolic blood pressure (DBP) (ES = -1.65 mmHg; 95% CI: 2.41, -0.90), total antioxidant capacity (TAC) (WMD = 0.34; 95% CI: 0.04, 0.64), and interleukin-6 (IL-6) (WMD = -1.48; 95% CI: 2.96, -0.01). However, the results did not show any significant effect of cinnamon on malondialdehyde (MDA) (WMD = -0.47; 95% CI: 0.99, 0.05), C-reactive protein (CRP) (WMD = -1.33; 95% CI: 2.66, 0.00), and intercellular adhesion molecule 1 (ICAM-1) (WMD= 1.53, 95% CI: 12.03, 15.10).

CONCLUSIONS

The results of the studies included in this umbrella review support the usefulness of cinnamon consumption in modulating BP as well as improving TAC and IL-6 in metabolic disorders. Due to the limited number of studies, clinical diversity, and other limitations, more high-quality studies must be conducted to provide more precise and comprehensive recommendations.

REGISTRATION NUMBER

PROSPERO, CRD42023487350.

Cardiovascular Effects of Herbal Products and Their Interaction with Antihypertensive Drugs-Comprehensive Review

Hypertension is a highly prevalent population-level disease that represents an important risk factor for several cardiovascular complications and occupies a leading position in mortality statistics. Antihypertensive therapy includes a wide variety of drugs. Additionally, the potential antihypertensive and cardioprotective effects of several phytotherapy products have been evaluated, as these could also be a valuable therapeutic option for the prevention, improvement or treatment of hypertension and its complications. The present review includes an evaluation of the cardioprotective and antihypertensive effects of garlic, Aloe vera, green tea, Ginkgo biloba, berberine, ginseng, Nigella sativa, Apium graveolens, thyme, cinnamon and ginger, and their possible interactions with antihypertensive drugs. A literature search was undertaken via the PubMed, Google Scholar, Embase and Cochrane databases. Research articles, systematic reviews and meta-analyses published between 2010 and 2023, in the English, Hungarian, and Romanian languages were selected.

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 consumption on lipid profile, oxidative stress, and inflammation biomarkers in adults: An umbrella meta-analysis of randomized controlled trials

AIMS

Cinnamon is a polyphenol-rich spice that has beneficial effects on markers of cardio metabolic health such as lipid profile, oxidative stress, and inflammation. Despite the accumulating evidence from meta-analyses on the effects of cinnamon on these markers, their findings are controversial. Thus, this umbrella meta-analysis was performed to evaluate the present evidence and provide a conclusive clarification.

DATA SYNTHESIS

We searched the following international databases from inception to January 2022: PubMed, Scopus, Web of Science and Embase, and Google Scholar. Our findings of eleven meta-analyses showed that cinnamon consumption can significantly improve total cholesterol (TC) (WMD = -1.01 mg/dL; 95% CI: -2.02, -0.00, p = 0.049), low-density lipoprotein-cholesterol (LDL-C) (WMD = -0.82 mg/dL; 95% CI: -1.57, -0.07, p = 0.032), and high-density lipoprotein-cholesterol (HDL-C) (WMD = 0.47 mg/dL; 95% CI: 0.17, 0.77, p = 0.002) levels but not triglyceride (TG) levels (WMD = -0.13 mg/dL; 95% CI: -0.58, 0.32, p = 0.570). Our results did not show any significant effect of cinnamon on malondialdehyde (MDA) levels (WMD = -0.47; 95% CI: -0.99, 0.05, p = 0.078) and C-reactive protein (CRP) levels (WMD = -1.33; 95% CI: -2.66, 0.00, p = 0.051) but there was enhanced total antioxidant capacity (TAC) in patients with type 2 diabetes (T2DM) and polycystic ovary syndrome (PCOS) (WMD = 0.34; 95% CI: 0.04, 0.64, p = 0.026) and increased levels of interleukin-6 (WMD = -1.48; 95% CI: -2.96, -0.01, p = 0.049).

CONCLUSIONS

Our results support the usefulness of cinnamon intake in modulating an imbalanced lipid profile in some metabolic disorders, particularly PCOS, as well as in improving TAC and interleukin-6. The review protocol was registered on PROSPERO as CRD42022358827.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Cinnamon as a Complementary Therapeutic Approach for Dysglycemia and Dyslipidemia Control in Type 2 Diabetes Mellitus and Its Molecular Mechanism of Action: A Review

The scientific evidence that cinnamon may exert beneficial effects on type 2 diabetes mellitus due to the biological activity of its bioactive compounds has been increasing in recent years. This review provides an overview of the effects of cinnamon on clinical parameters of diabetes and summarizes the molecular mechanisms of action of cinnamon on glucose and lipid metabolism. Search criteria include an electronic search using PubMed, Medline, and Cochrane Library databases. English literature references from 2000 up to 2022 were included. Following title and abstract review, full articles that met the inclusion criteria were included. The results from the available evidence revealed that cinnamon improved glycemic and lipidemic indicators. Clinical trials clarified that cinnamon also possesses an anti-inflammatory effect, which may act beneficially in diabetes. Based on in vitro and in vivo studies, cinnamon seems to elicit the regulation of glucose metabolism in tissues by insulin-mimetic effect and enzyme activity improvement. Furthermore, cinnamon seems to decrease cholesterol and fatty acid absorption in the gut. The current literature search showed a considerable number of studies on diabetic subjects. Some limitations in comparing published data should be highlighted, including variability in doses, extracts and species of cinnamon, administration forms, and antidiabetic therapy.

Phenolic Bioactives as Antiplatelet Aggregation Factors: The Pivotal Ingredients in Maintaining Cardiovascular Health

Cardiovascular diseases (CVD) are one of the main causes of mortality in the world. The development of these diseases has a specific factor-alteration in blood platelet activation. It has been shown that phenolic compounds have antiplatelet aggregation abilities and a positive impact in the management of CVD, exerting prominent antioxidant, anti-inflammatory, antitumor, cardioprotective, antihyperglycemic, and antimicrobial effects. Thus, this review is intended to address the antiplatelet activity of phenolic compounds with special emphasis in preventing CVD, along with the mechanisms of action through which they are able to prevent and treat CVD. In vitro and in vivo studies have shown beneficial effects of phenolic compound-rich plant extracts and isolated compounds against CVD, despite that the scientific literature available on the antiplatelet aggregation ability of phenolic compounds in vivo is scarce. Thus, despite the current advances, further studies are needed to confirm the cardioprotective potential of phenolic compounds towards their use alone or in combination with conventional drugs for effective therapeutic interventions.

What is the influence of cinnamon supplementation on liver enzymes? A systematic review and meta-analysis of randomized controlled trials

Existing evidence has uncovered the potential health benefits of cinnamon intake; however, its effect on liver function is unclear. Thus, the aim of this systematic review and meta-analysis was to examine the effect of cinnamon supplementation on liver enzymes. Relevant articles were identified through a systematic search in PubMed/Medline, Scopus, Web of Science, Cochrane Library, and Embase up to September 2020. All trials assessing the effect of oral cinnamon supplementation on serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in adults were included. The pooled effect sizes were obtained using the random-effects model and expressed as mean difference (MD) and 95% confidence intervals (CI). A total of seven original trials (nine treatment arms) involving a total of 256 subjects were included in the final analysis. The pooled analysis indicated that cinnamon supplementation had no significant effect on serum levels of ALT, AST, and ALP. However, there was a significant reduction in ALT levels in patients with type 2 diabetes (MD: -4.01 U/L; 95% CI: -6.86, -1.15) and in trials with low-dose supplementation (<1,500 mg/d), follow-up duration longer than 12 weeks, and in the elderly patients (aged>50 years). The beneficial effects of cinnamon intake were also shown in AST levels in patients with type 2 diabetes and trials with long-term follow-up (>12 weeks). Longer-term, oral cinnamon supplementation may improve serum levels of liver enzymes in patients with type 2 diabetes. Further high-quality studies are needed, especially in populations with abnormal liver enzyme levels, to firmly establish the clinical efficacy of cinnamon on liver function.

The effect of herbs and spices on risk factors for cardiometabolic diseases: a review of human clinical trials

Herbs and spices are recommended to increase flavor and displace salt in the diet. Accumulating evidence suggests herbs and spices may improve risk factors for cardiometabolic diseases. In this narrative review, an overview of evidence from human clinical trials examining the effect of herbs and spices on risk factors for cardiometabolic diseases is provided. Human clinical trials examining supplemental doses of individual spices and herbs, or the active compounds, have yielded some evidence showing improvements to lipid and lipoprotein levels, glycemic control, blood pressure, adiposity, inflammation, and oxidative stress. However, cautious interpretation is warranted because of methodological limitations and substantial between-trial heterogeneity in the findings. Evidence from acute studies suggests intake of mixed herbs and spices as part of a high-saturated fat, high-carbohydrate meal reduces postprandial metabolic impairments, including lipemia, oxidative stress, and endothelial dysfunction. Limited studies have examined the postprandial metabolic effects of incorporating mixed herbs and spices into healthy meals, and, to our knowledge, no trials have assessed the effect of longer-term intake of mixed herbs and spices on risk factors for cardiometabolic diseases. To inform evidence-based guidelines for intake of herbs and spices for general health and cardiometabolic disease risk reduction, rigorously conducted randomized controlled trials are needed, particularly trials examining herb and spice doses that can be incorporated into healthy dietary patterns.

Evaluation of the Effectiveness of Cinnamon Oil Soft Capsule in Patients with Functional Dyspepsia: A Randomized Double-Blind Placebo-Controlled Clinical Trial

Background

Different effects of cinnamon and its oil in traditional medicine in the treatment of diseases, including gastrointestinal diseases, were reported. The aim of this study is to evaluate the efficacy and safety of cinnamon oil (Cinnamomum zeylanicum) in patients with functional dyspepsia in a double-blind, randomized placebo-controlled trial.

Methods

Soft gelatin capsule was made using the rotary die process, and the final capsule was standardized based on its cinnamaldehyde amount and analyzed by high-performance liquid chromatography (HPLC) method. Sixty-four patients with symptomatic functional dyspepsia were randomized to receive cinnamon oil soft capsule (n = 29) or sesame oil soft capsule as placebo (n = 35) for 6 weeks. The primary efficacy variable was the sum score of the patient's gastrointestinal symptom (five‐point scale). Secondary variables were the scores of each dyspeptic symptom including severity of vomiting, sickness, nausea, bloating, abdominal cramps, early satiety, acidic eructation/heartburn, loss of appetite, retrosternal discomfort, and epigastric pain/upper abdominal pain, as well as any reported adverse events.

Results

The results showed that, after 6 weeks of treatment, the cinnamon oil and placebo groups significantly decreased the total dyspepsia score compared to the baseline at the endpoint (P < 0.001). However, there was no significant difference between the cinnamon oil and placebo groups in terms of the baseline and endpoint values of the outcome variables (P=0.317 and P=0.174, respectively). Two patients in the cinnamon oil group complained of rashes, and three patients in the placebo group complained of nausea.

Conclusion

This study showed significant improvements in gastrointestinal symptom score in both treatment and placebo groups. However, there was no significant difference between the cinnamon oil and sesame oil groups in terms of the baseline and endpoint values of the outcome variables. This study was registered as https://clinicaltrials.gov/ct2/show/IRCT20170802035460N2, 29 December 2017, in the Iranian Registry of Clinical Trials with https://www.IRCT.ir.

Cinnamomum Species: Bridging Phytochemistry Knowledge, Pharmacological Properties and Toxicological Safety for Health Benefits

The genus Cinnamomum includes a number of plant species largely used as food, food additives and spices for a long time. Different traditional healing systems have used these plants as herbal remedies to cure diverse ailments. The aim of this comprehensive and updated review is to summarize the biodiversity of the genus Cinnamomum, its bioactive compounds, the mechanisms that underlie the pharmacological activities and molecular targets and toxicological safety. All the data in this review have been collected from databases and recent scientific literature including Web of Science, PubMed, ScienceDirect etc. The results showed that the bioactive compounds of Cinnamomum species possess antimicrobial, antidiabetic, antioxidant, anti-inflammatory, anticancer and neuroprotective effects. The preclinical (in vitro/in vivo) studies provided the possible molecular mechanisms of these action. As a novelty, recent clinical studies and toxicological data described in this paper support and confirm the pharmacological importance of the genus Cinnamomum. In conclusion, the obtained results from preclinical studies and clinical trials, as well as reduced side effects provide insights into future research of new drugs based on extracts and bioactive compounds from Cinnamomum plants.

Effect of cinnamon on migraine attacks and inflammatory markers: A randomized double-blind placebo-controlled trial

Migraine is the most common type of primary headaches. Increased levels of interleukin-6 (IL-6), calcitonin-gene-related peptide (CGRP) and nitric oxide (NO) lead to inflammation and neurogenic pain. Cinnamon has anti-inflammatory and neuroprotective properties. Thus, the aim of this study was to assess the effect of cinnamon on migraine attacks and inflammatory status. Fifty patients with migraine were randomized to receive either cinnamon powder (three capsules/day each containing 600 mg of cinnamon) or three placebo capsules/day each containing 100 mg of corn starch (control group) for 2 months. Serum levels of IL-6, CGRP and NO were measured at baseline and at the end of the study. The frequency, severity and duration of pain attacks were also recorded using questionnaire. Serum concentrations of IL-6 and NO were significantly reduced in the cinnamon group compared with the control group (p < .05). However, serum levels of CGRP remained unchanged in both groups. The frequency, severity and duration of migraine attacks were significantly decreased in the cinnamon group compared with the control group. Cinnamon supplementation reduced inflammation as well as frequency, severity and duration of headache in patients with migraine. Cinnamon could be regarded as a safe supplement to relieve pain and other complications of migraine.

Anti-hypertensive effects of cinnamon supplementation in adults: A systematic review and dose-response Meta-analysis of randomized controlled trials

Background & Objectives: Despite controversies, no earlier study has systematically summarized findings from earlier studies on the effect of cinnamon supplementation on blood pressure. Therefore, current systematic review and meta-analysis was done on the effect of cinnamon supplementation on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults.Methods: Relevant studies published up to July 2019 were searched through PubMed/Medline, Scopus, ISI Web of Science, Embase and Google Scholar. All randomized clinical trials investigating the impact of oral cinnamon supplementation on any of the blood pressure parameters including SBP or/and DBP were included.Results: Out of 469 citations, 9 trials that enrolled 641 subjects were included. Cinnamon supplementation resulted in significant reduction in SBP (Weighted Mean Differences (WMD): -6.23 mmHg, 95% CI: -10.69 to -1.77, P = 0.006) and DBP (WMD: -3.93 mmHg, 95% CI: -6.33 to -1.52, P = 0.001). Greater effects on SBP were detected in trials using ≤2 g cinnamon, lasted ≥12 weeks and participants aged <50 years' old. DBP was also reduced by using lower doses. However, no significant non-linear associations were found between cinnamon supplementation dosage and study duration with both SBP (For dosage: P_{non-linearity} = 0.35, for duration: P_{non-linearity} = 0.21) and DBP (For dosage: P_{non-linearity} = 0.27, for duration: P_{non-linearity} = 0.41).Conclusions: We found a significant reduction in both SBP and DBP following cinnamon supplementation in adults. It could be proposed as a hypotensive supplement in hypertension management.