Reviewed: Hemati N, Venkatakrishnan K, Yarmohammadi S, et al. The effects of supplementation with Cynara scolymus L. on anthropometric indices: A systematic review and dose-response meta-analysis of clinical trials. Complement Ther Med. January 2021;56:102612. doi: 10.1016/j.ctim.2020.102612.
Obesity is a global health problem that is a risk factor for several chronic diseases, such as cardiovascular disorders, type 2 diabetes, liver disease, and cancer. Making sustainable lifestyle changes (e.g., decrease in calorie intake, increase in physical exercise) to combat the disorder can be difficult, and many people use various methods for weight loss, including dietary supplementation. Artichoke (Cynara cardunculus syn. C. scolymus, Asteraceae) contains phenolic compounds (e.g., ellagic acid), benzoic acid, and dietary fiber, which may contribute to anti-obesity effects. However, studies have had inconsistent results.
The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to determine the effects of artichoke supplementation on anthropometric indices such as body weight, body mass index (BMI), and waist circumference.
The study was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The Cochrane Library, Scopus, PubMed, and Embase databases were searched from inception to February 29, 2020, using medical subject headings, abstracts, and keywords without limitations. The authors included RCTs that reported the efficacy of artichoke supplementation on body weight, BMI, and waist circumference. They excluded studies with an intervention duration of less than two weeks and studies without a control group.
Cochrane Collaboration’s tool was used to assess study quality. Subgroup analyses were performed according to trial duration (8 or 12 weeks), artichoke dose (< 1,000 or ≥ 1,000 mg/day), type of intervention (powder or extract), participant weight status (normal, overweight, or obese), and participant health status (hypertensive and others).
Of the 538 studies identified, 10 studies consisting of 588 participants (n = 316 in artichoke group and n = 272 in placebo group) were included in the quantitative analysis. The studies were conducted between 2009 and 2019 in Iran, Italy, and South Korea. Participants (38 to 58 years old) were overweight and/or had nonalcoholic fatty liver disease (NAFLD), type 2 diabetes, hypercholesterolemia, and/or metabolic syndrome. Nine studies used placebos (no additional details provided), and one study used metformin, a prescription drug for diabetes, as a control. Three studies were considered low quality due to a lack of blinding, incomplete reporting of outcome measures, or potential study bias.
The artichoke dose ranged from 100 mg/day to 19.45 g/day, and the supplementation period ranged from 8 to 12 weeks. Six studies used artichoke leaf extracts, including one combination product with a standardized common bean (Phaseolus vulgaris, Fabaceae) extract; three studies used artichoke powders, including one combination product with fermented soybean (Glycine max, Fabaceae) powder; and one study used artichoke leaf juice. The authors did not include any additional information about the specific products used in the 10 studies.
A pooled analysis of the nine studies that assessed body weight demonstrated a small decrease in weight with artichoke supplementation. Only the subgroup analysis in participants with hypertension showed a significant effect on weight loss. Artichoke supplementation had an insignificant effect on BMI compared with placebo. Subgroup analyses did not show significantly different effects of artichoke on BMI. Waist circumference significantly decreased (P = 0.025) after artichoke supplementation compared with placebo. The dose-response analysis revealed no significant dose-dependent changes in weight or BMI.
According to the authors, this meta-analysis is the first to examine the effects of artichoke supplementation on anthropometric indices. Artichoke supplementation showed a significant effect on waist circumference, but not on body weight or BMI. In participants with hypertension, subgroup analysis revealed a significant reduction in weight, suggesting that the addition of artichoke could be recommended to this clinical population for weight management. Limitations cited by the authors were the small number of included studies and the lack of publication bias and sensitivity analysis tests for waist circumference. Further clinical trials among participants with obesity and other clinical populations are needed to better understand the effects of artichoke supplementation on anthropometric indices.