Soy protein's ability to lower total and LDL (low-density lipoprotein or "the bad") cholesterol has been extensively studied, but the mechanism whereby soy protein lowers cholesterol remains unresolved. A new study published in the Journal of Clinical Lipidology last month shows that soy protein lowers total cholesterol and non-HDL (non-high-density lipoprotein) cholesterol significantly more than milk protein in patients with moderately high cholesterol levels.
"Non-HDL cholesterol has been shown to be a somewhat stronger predictor of cardiovascular disease and mortality risk than LDL cholesterol in population studies," said Elaine Krul, co-author of the study and nutrition discovery lead at Solae. "The fact that soy protein significantly decreased non-HDL cholesterol levels compared to milk protein in this study is very promising."
This randomized, controlled, parallel arm trial evaluated the effects of an insoluble fraction of soy protein, compared to total milk proteins with high calcium content, on the fasting lipid profile. It also assessed the potential contributions of increased excretion of bile acids and neutral sterols to their lipid-altering effects.
"The results of this study also showed that soy protein lowered non-HDL through a mechanism that does not involve increased bile acid excretion, but some yet to be determined mechanism," said Kevin Maki, lead author of the study. "Nonetheless, these results are supportive of the heart health claim for soy protein."
The Food and Drug Administration (FDA) heart health claim for soy protein established in 1999 states that "25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease." Currently, 11 other countries have approved health claims for soy protein's potential to lower blood cholesterol and lower the risk of coronary heart disease.
Solae's soy protein that was used in this study
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