Epidemiological studies suggest that soy might be associated with a lower risk of certain chronic diseases. This has lead health regulatory agencies worldwide to approve food-labeling health claim for soy proteins.

Dr. Chao Wu Xiao at the University of Ottawa in Canada finds the data lacking.

First, the details.

• The Nutrition Committee of the American Heart Association assessed 22 studies conducted since 1999.

And, the results.

• Isolated soy protein with isoflavones slightly decreased LDL (bad) cholesterol but had no effect on HDL (good) cholesterol, triglycerides, lipoprotein(a), or blood pressure.
• Other effects of soy consumption were not evident.
• Some studies have documented potential safety concerns over increased consumption of soy products.
• The impact of soy products on thyroid and reproductive functions, as well as on certain types of cancer, require further study.

The bottom line?
Dr. Wu Xiao says “The source of soybeans and processing procedures of the protein or isoflavones are believed to be important because of their effects on … certain bioactive protein subunits.”

But overall, “Existing data are inconsistent or inadequate in supporting most of the suggested health benefits of consuming soy protein or isoflavones.”

Another example of hype preceding science?

8/23/08 17:13 JR