Like many other misconceptions, the "soy and men" misconception has a kernel of truth, which has been grossly exaggerated along the way.
There are 2 case studies in which men experienced rather alarming hormonal effects as a result of consuming extremely large amounts of soy foods on a daily basis. Here are those case studies, with links:
In a 2008 case study, a 60-year old male developed enlarged breast issue and erectile dysfunction as a result of drinking 3 quarts of soymilk (
12 servings) per day, every day. Only 3-4 servings of calcium-fortified soymilk are needed to achieve 100% RDI of calcium. Here is the abstract of that case study:
https://www.ncbi.nlm.nih.gov/pubmed/18558591
In a 2011 case study, a 19-year old male developed erectile dysfunction as a result of consuming
14 servings of soy foods per day. Here is the abstract of that case study:
https://www.ncbi.nlm.nih.gov/pubmed/21353476 (unfortunately, the full text of the study can only be seen by purchasing it).
Note that, after these men discontinued consuming their massive daily servings of soy, their bodies returned to normal.
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