Olive leaf extract effect on cardiometabolic risk factors: a systematic review and meta-analysis of randomized clinical trials

CONTEXT

Olive leaf extract (OLE) is rich in phenolic compounds, which are known for their health benefits. Cardiovascular diseases, primarily coronary heart disease and stroke, are leading causes of mortality globally.

OBJECTIVE

This systematic review aimed to assess the impact of OLE on cardiometabolic risk factors in adults. The selection of studies was based on intervention and outcomes, using relevant search descriptors.

DATA SOURCES

The databases PubMed, EMBASE, and Web of Science were systematically searched for pertinent studies published up to August 2021.

DATA EXTRACTION

Only randomized clinical trials, either cross-over or parallel, involving adult individuals aged ≥18 years, were considered. Additionally, trials that had a comparative or placebo group and used pure OLEs for oral treatment were included.

DATA ANALYSIS

Twelve randomized clinical trials (RCTs) met the inclusion criteria. These trials had follow-up periods ranging from 2 days to 12 weeks and involved 703 patients aged 18 years-79 years. The outcomes demonstrated a positive correlation between the intervention group and glucose metabolism (4 RCTs), blood pressure (2 RCTs), lipid profile (2 RCTs), and inflammatory markers (2 RCTs). The RoB2 tool and the GRADE system were used to evaluate the risk of bias and the quality of evidence in the studies.

CONCLUSIONS

In the meta-analysis, fasting glycemia, as evaluated in studies using a low dose of OLE, showed a significant result favoring the control group. To obtain more consistent results, further clinical studies in humans, using similar methodologies, are required.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020200877.

Effects of Zinc Supplementation on Inflammatory and Cognitive Parameters in Middle-Aged Women with Overweight or Obesity

Obesity has been linked to cognitive decline and adverse effects on brain health. Zinc (Zn) is a mineral with important metabolic functions that can modulate obesity-related neurological impairment. Thus, the present study aimed to evaluate the effects of 12 weeks of Zn supplementation on the inflammatory profile, cognitive function, and mood of overweight or obese women through a double-blind, placebo-controlled study. The study included 42 women aged between 40 and 60, randomly divided into two groups: Zn supplementation (30 mg/day) or placebo for 12 weeks. Data regarding sociodemographic, anthropometric, dietary, and physical activity were collected. Mini-mental state examination (MMSE), verbal fluency test, clock drawing test, and Stroop test were performed. Anxiety and depression symptoms were assessed using the Beck anxiety inventory and the BDI-II, respectively. Saliva samples were collected to evaluate IL-1β, IL-6, TNF-α, insulin, nitrite, and Zn levels. Of the 42 participants (mean age 49.58 ± 6.46 years), 32 were included in the study analyses. Changes in body weight and macronutrient consumption were not different between placebo and Zn supplementation groups. Cognitive scores on the MMSE and Stroop tests were higher in the Zn supplementation group than in the placebo group. Salivary levels of IL-1b and Zn increased in the Zn group compared to placebo. There was no significant change in the adjusted means of the BDI-II and BECK scores between the zinc vs. placebo groups. Twelve weeks of Zn supplementation was able to partially improve the cognitive scores assessed in overweight or obese women, regardless of weight loss. These findings suggest that Zn supplementation can be considered an adjunct strategy to enhance cognitive health in overweight or obese women.

Efficacy of telemedicine interventions for depression and anxiety in older people: A systematic review and meta-analysis

OBJECTIVES

Anxiety and depression are prevalent in the elderly and lead to loss of functionality and increased mortality. Although the use of antidepressants and face-to-face psychotherapies are indicated, the current context of telemedicine provides an alternative, with the advantage of facilitating access to care. The study aimed to evaluate the efficacy of telemedicine interventions to reduce anxiety and depression in the elderly through a systematic review with meta-analysis.

METHODS

The systematic review, through a search in 7 databases, included studies that evaluated the use of telemedicine interventions for depressive or anxious symptoms in the elderly, compared with usual care or waiting list or with another telemedicine intervention. Quantitative assessment was performed through meta-analysis.

RESULTS

A total of 31 articles identified in the search met the eligibility criteria and four were included for meta-analysis. Studies showed that telemedicine interventions are feasible and several studies demonstrated significant improvement in depressive or anxiety symptoms. Four studies evaluated the efficacy of internet-delivered cognitive behavioral therapy for depression and anxiety in older adults, compared with a waitlist, and found pooled effect sizes of -1.20 (95% CI -1.60 to -0.81) and -1.14 (95% CI -1.56 to -0.72), respectively, with low heterogeneity.

CONCLUSIONS

Telemedicine interventions can be an alternative for the treatment of mood and anxiety symptoms in the elderly. However, more studies are needed to prove their clinical effectiveness, especially in countries with lower incomes and diverse culture and education.