The effects of flaxseed (Linum usitatissimum) supplementation on anthropometric indices: An updated systematic review and meta-analysis of randomized clinical trials
{"title":"The effects of flaxseed (Linum usitatissimum) supplementation on anthropometric indices: An updated systematic review and meta-analysis of randomized clinical trials","authors":"","doi":"10.1016/j.ctim.2024.103066","DOIUrl":null,"url":null,"abstract":"<div><h3>Objective</h3><p>Flaxseed (<em>Linum usitatissimum</em>) supplementation has shown promise as an anti-obesity agent in various clinical trials, although results have been inconsistent. To provide a more accurate assessment of the impact of flaxseed supplementation on anthropometric indices, a systematic review and meta-analysis was performed.</p></div><div><h3>Methods</h3><p>We searched several international databases until August 2023, including Scopus, PubMed, Web of Science, Embase, and Cochrane Library. Weighted mean differences (WMDs) were analyzed using a random-effects model.</p></div><div><h3>Results</h3><p>Sixty-four trials comprising 72 treatment arms were included. All studies reported the intervention types (Lignans, Whole flaxseed, and Flaxseed oil) and dosage. However, three studies did testing for purity, and 40 studies reported potency. Also, the risk of contamination with heavy metals was not mentioned in studies. Another limitation was the lack of blind evaluation in the studies. According to three trials included in the systematic review, flaxseed did not affect anthropometric indices. Our meta-analysis revealed significant reductions in body weight (WMD = −0.63 kg; 95 % CI: −1.00, −0.27, P < 0.001; I<sup>2</sup> = 76.7 %, P < 0.001), body mass index (BMI) (WMD: −0.24 kg/m2, 95 % CI: −0.36, −0.11, P < 0.001; I<sup>2</sup> = 78.5 %, P < 0.001) and waist circumference (WC) (WMD: −1.43 cm, 95 % CI: −2.06, −0.80, P < 0.001; I<sup>2</sup> = 81.1 %, P < 0.001) following flaxseed supplementation. Subgroup analyses indicated that interventions lasting 10–20 weeks, and studies involving subjects with higher BMI (>30 kg/m<sup>2</sup>) showed more significant anti-obesity effects. Based on the GRADE evaluation, body weight, BMI, and WC results were considered as moderate-certainty evidence.</p></div><div><h3>Conclusion</h3><p>Our systematic review and meta-analysis suggests that supplementation with flaxseed <em>(Linum usitatissimum</em>) leads to meaningful improvements in body weight, BMI, and WC. Therefore, flaxseed can be considered as an adjunctive therapeutic approach in improving obesity</p></div>","PeriodicalId":10545,"journal":{"name":"Complementary therapies in medicine","volume":"84 ","pages":"Article 103066"},"PeriodicalIF":3.3000,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0965229924000542/pdfft?md5=478ec8d9c392acdc9fbc30e78ecfa739&pid=1-s2.0-S0965229924000542-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Complementary therapies in medicine","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0965229924000542","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"INTEGRATIVE & COMPLEMENTARY MEDICINE","Score":null,"Total":0}
引用次数: 0
Abstract
Objective
Flaxseed (Linum usitatissimum) supplementation has shown promise as an anti-obesity agent in various clinical trials, although results have been inconsistent. To provide a more accurate assessment of the impact of flaxseed supplementation on anthropometric indices, a systematic review and meta-analysis was performed.
Methods
We searched several international databases until August 2023, including Scopus, PubMed, Web of Science, Embase, and Cochrane Library. Weighted mean differences (WMDs) were analyzed using a random-effects model.
Results
Sixty-four trials comprising 72 treatment arms were included. All studies reported the intervention types (Lignans, Whole flaxseed, and Flaxseed oil) and dosage. However, three studies did testing for purity, and 40 studies reported potency. Also, the risk of contamination with heavy metals was not mentioned in studies. Another limitation was the lack of blind evaluation in the studies. According to three trials included in the systematic review, flaxseed did not affect anthropometric indices. Our meta-analysis revealed significant reductions in body weight (WMD = −0.63 kg; 95 % CI: −1.00, −0.27, P < 0.001; I2 = 76.7 %, P < 0.001), body mass index (BMI) (WMD: −0.24 kg/m2, 95 % CI: −0.36, −0.11, P < 0.001; I2 = 78.5 %, P < 0.001) and waist circumference (WC) (WMD: −1.43 cm, 95 % CI: −2.06, −0.80, P < 0.001; I2 = 81.1 %, P < 0.001) following flaxseed supplementation. Subgroup analyses indicated that interventions lasting 10–20 weeks, and studies involving subjects with higher BMI (>30 kg/m2) showed more significant anti-obesity effects. Based on the GRADE evaluation, body weight, BMI, and WC results were considered as moderate-certainty evidence.
Conclusion
Our systematic review and meta-analysis suggests that supplementation with flaxseed (Linum usitatissimum) leads to meaningful improvements in body weight, BMI, and WC. Therefore, flaxseed can be considered as an adjunctive therapeutic approach in improving obesity
期刊介绍:
Complementary Therapies in Medicine is an international, peer-reviewed journal that has considerable appeal to anyone who seeks objective and critical information on complementary therapies or who wishes to deepen their understanding of these approaches. It will be of particular interest to healthcare practitioners including family practitioners, complementary therapists, nurses, and physiotherapists; to academics including social scientists and CAM researchers; to healthcare managers; and to patients. Complementary Therapies in Medicine aims to publish valid, relevant and rigorous research and serious discussion articles with the main purpose of improving healthcare.