Effects of Melissa officinalis (Lemon Balm) on cardio-metabolic outcomes: A systematic review and meta-analysis.

2020-07-02
Phytotherapy research : PTR 34(12)
- Javad Heshmati
- Mojgan Morvaridzadeh
- Mahdi Sepidarkish
- Siavash Fazelian
- Mehran Rahimlou
- Amirhossein Omidi
- Andriko Palmowski
- Akbar Asadi
- Farzad Shidfar

PubMed: 32614129
DOI: 10.1002/ptr.6744

Study Design

Type: Meta-Analysis
Methods: Systematic review and meta-analysis of RCTs; searched MEDLINE, Scopus, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials; random-effects meta-analysis for pooled SMD.

Recent evidence indicates a beneficial effect of Melissa officinalis (MO) intake on several chronic diseases. However, the effects of MO intake have not yet been systematically reviewed. Therefore, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of MO intake and focused on several cardiometabolic outcomes. MEDLINE, Scopus, EMBASE, Web of Science and the Cochrane Central Register of Controlled Trials were searched for MO-RCTs evaluating cardiometabolic outcomes. Random-effects meta-analyses estimated the pooled standardized mean differences (SMD) between intervention and control groups. Risk of bias was assessed with the Cochrane Collaboration's tool for assessing the risk of bias in RCTs. Seven RCTs were finally deemed eligible. MO intake was associated with a reduced total cholesterol (TC) (SMD: -0.26; 95% CI: -0.52, -0.01; I² = 13.7%; k = 6) and a reduced systolic blood pressure (SBP) (SMD: -0.56; 95% CI: -0.85, -0.27; I² = 00.0%; k = 3). MO intake was not associated with statistically significant changes in triglycerides, low-density lipoprotein, diastolic blood pressure, high sensitivity c-reactive protein levels, fasting blood sugar, HbA1c, insulin or high-density lipoprotein levels. No serious adverse events were reported. The risk of bias was high in a considerable amount of studies. Our study suggests that MO is a safe supplement with beneficial effects on TC and SBP. However, the findings of our study must be seen in the light of major limitations such as a low number of included studies and a serious risk of bias. High-quality RCTs are needed for firm conclusions concerning the effects of MO on cardiometabolic outcomes.

Research Insights

Lemon Balm→Improved Insulin Levels
MO intake was not associated with statistically significant changes in … insulin
Effect
Neutral
Effect size
Small
Lemon Balm→Reduced Blood Cholesterol
MO intake was associated with a reduced total cholesterol (TC) (SMD: -0.26; 95% CI: -0.52, -0.01; I² = 13.7%; k = 6)
Effect
Beneficial
Effect size
Small
Lemon Balm→Reduced Diastolic Blood Pressure
MO intake was not associated with statistically significant changes in … diastolic blood pressure
Effect
Neutral
Effect size
Small
Lemon Balm→Reduced Fasting Blood Glucose Levels
MO intake was not associated with statistically significant changes in … fasting blood sugar
Effect
Neutral
Effect size
Small
Lemon Balm→Reduced Hemoglobin A1c
MO intake was not associated with statistically significant changes in … HbA1c
Effect
Neutral
Effect size
Small
Lemon Balm→Reduced High-Sensitivity C-Reactive Protein Level
MO intake was not associated with statistically significant changes in … high sensitivity c-reactive protein levels
Effect
Neutral
Effect size
Small
Lemon Balm→Reduced Low-Density Lipoprotein Level
MO intake was not associated with statistically significant changes in … high-density lipoprotein levels
Effect
Neutral
Effect size
Small
Lemon Balm→Reduced Systolic Blood Pressure
a reduced systolic blood pressure (SBP) (SMD: -0.56; 95% CI: -0.85, -0.27; I² = 00.0%; k = 3)
Effect
Beneficial
Effect size
Moderate
Lemon Balm→Reduced Triglyceride Levels
MO intake was not associated with statistically significant changes in triglycerides
Effect
Neutral
Effect size
Small

Adverse Events Reported

Lemon Balm→Overall tolerability
No serious adverse events were reported.
Finding
Reported
Severity
Serious adverse event