Soy reportedly lowers LDL (bad) cholesterol blood levels a little, while the data on probiotics are mixed.

Would it help to combine them? Here’s a study that tries.

First, the details.

  • 36 men and post-menopausal women with high cholesterol blood levels were studied.
  • They were assigned to receive a dietary combination of soy with either a probiotic (yogurt) or a prebiotic (resistant starch), or a control soy diet.

And the results.

  • Soy+probiotic significantly decreased total cholesterol (5%).
  • Soy+prebiotic significantly decreased total cholesterol (6%) and LDL cholesterol (7%).

The bottom line?
The authors concluded, “Dietary combination of soy with either a probiotic or a prebiotic resulted in significant lipid lowering.”

Maybe. But in the absence of a placebo treatment group it’s impossible to determine the contributions of soy on lipid lowering. To the contrary, Dr. Gerald Gau, a cardiologist from the Mayo Clinic disputes it’s value, saying “Separate analysis of soy isoflavones found they had no effect on lowering LDL cholesterol.”

Taking the pre or probiotic alone might be sufficient. But you can’t tell from this study.

10/18/07 21:16 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.