Effect of flaxseed consumption on central obesity, serum lipids, and adiponectin level in overweight or obese women: A randomised controlled clinical trial

The effects of flaxseed (Linum usitatissimum) supplementation on anthropometric indices: An updated systematic review and meta-analysis of randomized clinical trials

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.

Effect of Alpha-Linolenic Acid Supplementation on Cardiovascular Disease Risk Profile in Individuals with Obesity or Overweight: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Overweight and obesity are highly prevalent worldwide and are associated with cardiovascular disease (CVD) risk factors, including systematic inflammation, dyslipidemia, and hypertension. Alpha-linolenic acid (ALA) is a plant-based essential polyunsaturated fatty acid associated with reduced CVD risks. This systematic review and meta-analysis aimed to investigate the effects of supplementation with ALA compared with the placebo on CVD risk factors in people with obesity or overweight (International Prospective Register of Systematic Reviews Registration No. CRD42023429563). This review included studies with adults using oral supplementation or food or combined interventions containing vegetable sources of ALA. All studies were randomly assigned trials with parallel or crossover designs. The Cochrane Collaboration tool was used for assessing the risk of bias (Version 1). PubMed, Web of Science, Embase, and Cochrane library databases were searched from inception to April 2023. Nineteen eligible randomized controlled trials, including 1183 participants, were included in the meta-analysis. Compared with placebo, dietary ALA supplementation significantly reduced C-reactive protein concentration (standardized mean difference [SMD] = -0.38 mg/L; 95% confidence interval [CI]: -0.72, -0.04), tumor necrosis factor-α concentration (SMD = -0.45 pg/mL; 95% CI: -0.73, -0.17), triglyceride in serum (SMD = -4.41 mg/dL; 95% CI: -5.99, -2.82), and systolic blood pressure (SMD = -0.37 mm Hg; 95% CI: -0.66, -0.08); but led to a significant increase in low-density lipoprotein cholesterol concentrations (SMD = 1.32 mg/dL; 95% CI: 0.05, 2.59). ALA supplementation had no significant effect on interleukin-6, diastolic blood pressure, total cholesterol, or high-density lipoprotein cholesterol (all P ≥ 0.05). Subgroup analysis revealed that ALA supplementation at a dose of ≥3 g/d from flaxseed and flaxseed oil had a more prominent effect on improving CVD risk profiles, particularly where the intervention duration was ≥12 wk and where the baseline CVD profile was poor.

A comprehensive review on recent novel food and industrial applications of flaxseed: 2014 onwards

Flaxseed or linseed is an oilseed obtained from a plant, known as the flax (Linum usitatissimum). It is a valuable source of various bioactive components such as omega-3 polyunsaturated fatty acids, proteins, lignans, dietary fibres and phytochemicals. The in-vivo, in-vitro studies and research on human subjects and in animal models, conducted throughout the globe, on health benefits associated with the consumption of various forms of flaxseed are discussed in this review. It provides an insight into recent developments and potential applications of flaxseeds in the form of whole seeds, meals, flour or oil in an array of food and feed products and non-food industrial applications. The details about novel health benefits associated with flaxseeds and information related to commercially available flaxseed-based i.e. enriched products are also the salient feature of the review. Here, we have provided the state of the art of most recent comprehensive information post the first detailed review on flaxseed as a modern food released in 2014.

A comprehensive review on recent novel food and industrial applications of flaxseed: 2014 onwards

Flaxseed or linseed is an oilseed obtained from a plant, known as the flax (Linum usitatissimum). It is a valuable source of various bioactive components such as omega-3 polyunsaturated fatty acids, proteins, lignans, dietary fibres and phytochemicals. The in-vivo, in-vitro studies and research on human subjects and in animal models, conducted throughout the globe, on health benefits associated with the consumption of various forms of flaxseed are discussed in this review. It provides an insight into recent developments and potential applications of flaxseeds in the form of whole seeds, meals, flour or oil in an array of food and feed products and non-food industrial applications. The details about novel health benefits associated with flaxseeds and information related to commercially available flaxseed-based i.e. enriched products are also the salient feature of the review. Here, we have provided the state of the art of most recent comprehensive information post the first detailed review on flaxseed as a modern food released in 2014.