Effect of Plant Protein on Blood Lipids: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials

Abstract

BackgroundThere is a heightened interest in plant‐based diets for cardiovascular disease prevention. Although plant protein is thought to mediate such prevention through modifying blood lipids, the effect of plant protein in specific substitution for animal protein on blood lipids remains unclear. To assess the effect of this substitution on established lipid targets for cardiovascular risk reduction, we conducted a systematic review and meta‐analysis of randomized controlled trials using the Grading of Recommendations Assessment, Development, and Evaluation system.Methods and Results MEDLINE, EMBASE, and the Cochrane Registry were searched through September 9, 2017. We included randomized controlled trials of ≥3 weeks comparing the effect of plant protein in substitution for animal protein on low‐density lipoprotein cholesterol, non–high‐density lipoprotein cholesterol, and apolipoprotein B. Two independent reviewers extracted relevant data and assessed risk of bias. Data were pooled by the generic inverse variance method and expressed as mean differences with 95% confidence intervals. Heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). The overall quality (certainty) of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system. One‐hundred twelve randomized controlled trials met the eligibility criteria. Plant protein in substitution for animal protein decreased low‐density lipoprotein cholesterol by 0.16 mmol/L (95% confidence interval, −0.20 to −0.12 mmol/L; P<0.00001; I2=55%; moderate‐quality evidence), non–high‐density lipoprotein cholesterol by 0.18 mmol/L (95% confidence interval, −0.22 to −0.14 mmol/L; P<0.00001; I2=52%; moderate‐quality evidence), and apolipoprotein B by 0.05 g/L (95% confidence interval, −0.06 to −0.03 g/L; P<0.00001; I2=30%; moderate‐quality evidence).ConclusionsSubstitution of plant protein for animal protein decreases the established lipid targets low‐density lipoprotein cholesterol, non–high‐density lipoprotein cholesterol, and apolipoprotein B. More high‐quality randomized trials are needed to improve our estimates.Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT02037321.

Replacing Animal-Based Proteins with Plant-Based Proteins Changes the Composition of a Whole Nordic Diet—A Randomised Clinical Trial in Healthy Finnish Adults

“…The decrease in the cholesterol intake may also have had a role in these changes at least in some individuals. Our result is in line with earlier meta-analysis data on RCT's related to the effects of plant-based diets on lipoprotein profile [14,15] as well as what has been observed in vegans [25]. Overall, our results support epidemiological findings on a decreased risk of CVD associated with plant protein intake e.g., [26], which thus can be explained by the changes in the composition of whole diet and not by protein per se.…”

“…Clinical trials have offered insights into the mechanisms whereby dietary protein sources may mediate their effects on risk of chronic diseases. Meta-analyses of randomised controlled trials found that substitution of plant protein for animal protein decreased low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B [14,15]. Higher protein intake, particularly from plant-based sources, may also be associated with attenuated inflammatory burden in aging populations [16].…”

Effects of red meat, white meat, and nonmeat protein sources on atherogenic lipoprotein measures in the context of low compared with high saturated fat intake: a randomized controlled trial

“…Observational studies suggest that red meat intake is associated with increased cardiovascular disease (CVD) risk (1,2), whereas no such association has been observed with regular consumption of poultry (3). Conversely, plant protein sources and vegetarian dietary patterns appear to be cardioprotective (4,5), a finding supported by a systematic review of randomized controlled trials showing decreased LDL cholesterol (0.16 mmol/L), non-HDL cholesterol (0.18 mmol/L), and apolipoprotein B (apoB) (0.05 g/L) when animal protein is replaced with plant protein (6). Because it is well known that dietary saturated fatty acids (SFAs) increase plasma concentrations of LDL cholesterol, it has been generally assumed that the SFA content of red meat contributes to its association with CVD risk (7,8).…”

Nutrigenomics as a Tool in the Prevention of Lipotoxicity: The Case of Soy Protein

“…Some studies have shown that the consumption of soy protein can be used as part of the dietary strategy for the treatment of several pathological conditions, including renal disease [62][63][64][65] and elevated concentration of low-density lipoproteins (LDL)cholesterol 66,67 . In addition, the use of soy protein has been shown to attenuate the development of lipotoxicity in several organs, as described below.…”