New meta-analysis confirms soy protein does significantly lower total and LDL-cholesterol
A new meta-analysis has confirmed that a daily consumption of 25g soy protein could result in a modest but significant reduction in total and LDL-cholesterol – beyond the effect seen from lowering saturated fat intake.
The authors undertook the analysis on 46 randomized-controlled studies selected by the American health claims authority (Food and Drug Administration – FDA) for their review of the currently approved soy health claim. The analysis included a total of 2,607 men and women with a mean baseline total and LDL-C of 226.3mg/dL (5.85mmol/L) and 147.6mg/dL (3.82mmol/L) respectively.
Over a median 6-week period, consumption of 25g soy protein daily significantly reduced:
- LDL-cholesterol by -3.2% (ranging from -1.9% to -4.5%): -4.76mg/dL (range -2.8 to -6.71) / -0.12mmol/L (-0.07 to -0.17)
- Total cholesterol by -2.8% (ranging from -1.5% to -4.1%): -6.41mg/dL (range -3.52 to -9.3) / -0.17mmol/L (-0.09 to -0.24)
The study also confirmed this effect to be intrinsic and further reductions could be gained if the soy food consumed displaced higher saturated fat foods in the diet.
The study did not identify a dose-dependent response, however, the authors do note that eight of the studies used less than 25g soy protein.
Inclusion of soy foods and drinks is in line with current heart health organizations’ dietary recommendations, which encourage increased consumption of lower saturated fat plant-based protein foods in place of higher saturated fat animal proteins. This study confirms soy protein reduces cholesterol levels beyond the effect of displacing saturated fat in the diet: an additional 2.8% reduction in total and 3.2% LDL-cholesterol.
Sonia Blanco Mejia et al. A Meta-Analysis of 46 Studies Identified by the FDA Demonstrates that Soy Protein Decreases Circulating LDL and Total Cholesterol Concentrations in Adults. J Nutr 2019 Apr 22: Epub ahead of print doi: 10.1093/jn/nxz020.