Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2019 Jun 1;149(6):968-981.
doi: 10.1093/jn/nxz020.

A Meta-Analysis of 46 Studies Identified by the FDA Demonstrates that Soy Protein Decreases Circulating LDL and Total Cholesterol Concentrations in Adults

Sonia Blanco Mejia  1   2 , Mark Messina  3 , Siying S Li  1   4 , Effie Viguiliouk  1   2 , Laura Chiavaroli  1   2 , Tauseef A Khan  1   2 , Korbua Srichaikul  1 , Arash Mirrahimi  1 , John L Sievenpiper  1   2   5   6   7 , Penny Kris-Etherton  8 , David J A Jenkins  1   2   5   6   7
Affiliations
Meta-Analysis

A Meta-Analysis of 46 Studies Identified by the FDA Demonstrates that Soy Protein Decreases Circulating LDL and Total Cholesterol Concentrations in Adults

Sonia Blanco Mejia et al. J Nutr. .

Abstract

Background: Certain plant foods (nuts and soy protein) and food components (viscous fibers and plant sterols) have been permitted by the FDA to carry a heart health claim based on their cholesterol-lowering ability. The FDA is currently considering revoking the heart health claim for soy protein due to a perceived lack of consistent LDL cholesterol reduction in randomized controlled trials.

Objective: We performed a meta-analysis of the 46 controlled trials on which the FDA will base its decision to revoke the heart health claim for soy protein.

Methods: We included the 46 trials on adult men and women, with baseline circulating LDL cholesterol concentrations ranging from 110 to 201 mg/dL, as identified by the FDA, that studied the effects of soy protein on LDL cholesterol and total cholesterol (TC) compared with non-soy protein. Two independent reviewers extracted relevant data. Data were pooled by the generic inverse variance method with a random effects model and expressed as mean differences with 95% CI. Heterogeneity was assessed and quantified.

Results: Of the 46 trials identified by the FDA, 43 provided data for meta-analyses. Of these, 41 provided data for LDL cholesterol, and all 43 provided data for TC. Soy protein at a median dose of 25 g/d during a median follow-up of 6 wk decreased LDL cholesterol by 4.76 mg/dL (95% CI: -6.71, -2.80 mg/dL, P < 0.0001; I2 = 55%, P < 0.0001) and decreased TC by 6.41 mg/dL (95% CI: -9.30, -3.52 mg/dL, P < 0.0001; I2 = 74%, P < 0.0001) compared with non-soy protein controls. There was no dose-response effect or evidence of publication bias for either outcome. Inspection of the individual trial estimates indicated most trials (∼75%) showed a reduction in LDL cholesterol (range: -0.77 to -58.60 mg/dL), although only a minority of these were individually statistically significant.

Conclusions: Soy protein significantly reduced LDL cholesterol by approximately 3-4% in adults. Our data support the advice given to the general public internationally to increase plant protein intake. This trial was registered at clinicaltrials.gov as NCT03468127.

Keywords: LDL cholesterol; cardiovascular disease prevention; lipids; meta-analysis; soy protein; total cholesterol.

PubMed Disclaimer

Figures

FIGURE 1
FIGURE 1
Study selection indicating the number of studies identified by the FDA and the number of studies included in the meta-analysis.
FIGURE 2
FIGURE 2
Forest plot for the effect of soy protein intake on circulating LDL cholesterol concentration in adults. Overall effect is represented by the black diamond. 1Total n = 37, but reported n = 71 for soy protein diets and n = 72 for milk protein diets. 2Twelve subjects were excluded in data analysis in test 1 and 7 in test 2, but it was not specified from which arm; 50% dropout rate was taken from each. Data are expressed as mean differences with 95% CIs, using the generic inverse variance method with random effects models. Paired analyses were applied to all crossover studies. Interstudy heterogeneity was tested by the Cochran Q statistic at a significance level of P < 0.10 and quantified by I2; level of ≥50% represented substantial heterogeneity. n, number of participants.
FIGURE 3
FIGURE 3
Forest plot for the effect of soy protein intake on circulating TC concentration in adults. Overall effect is represented by the black diamond. 1Total n = 37, but reported n = 71 for soy protein diets and n = 72 for milk protein diets. 2Twelve subjects were excluded in data analysis in test 1 and 7 in test 2, but it was not specified from which arm; 50% dropout rate was taken from each. Data are expressed as mean differences with 95% CIs, using the generic inverse variance method with random effects models. Paired analyses were applied to all crossover studies. Interstudy heterogeneity was tested by the Cochran Q statistic at a significance level of P < 0.10 and quantified by I2; level of ≥50% represented substantial heterogeneity. n, number of participants; TC, total cholesterol.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Food and Drug Administration. Proposed rules. Fed Regist. 2017;82(209).
    1. Sacks FM, Lichtenstein A, Van Horn L, Harris W, Kris-Etherton P, Winston M; American Heart Association Nutrition Committee. Soy protein, isoflavones, and cardiovascular health: an American Heart Association Science Advisory for professionals from the Nutrition Committee. Circulation. 2006;113(7):1034–44. - PubMed
    1. Jenkins DJ, Mirrahimi A, Srichaikul K, Berryman CE, Wang L, Carleton A, Abdulnour S, Sievenpiper JL, Kendall CW, Kris-Etherton PM. Soy protein reduces serum cholesterol by both intrinsic and food displacement mechanisms. J Nutr. 2010;140(12):2302S–11S. - PubMed
    1. Erdman JW., Jr ASA science advisory: soy protein and cardiovascular disease: a statement for healthcare professionals from the Nutrition Committee of the AHA. Circulation. 2000;102(20):2555–9. - PubMed
    1. NutHealth.org. FDA approves the first qualified health claim: tree nuts and heart disease prevention takes the lead[Internet]. 2003[cited 10 August, 2018]. Available from: https://www.nuthealth.org/fda-approves-the-first-qualified-health-claim-..., accessed 10 August, 2018.

Publication types

Associated data

Grants and funding