The raison d'etre of this website is to provide you with hard scientific information which may help you make informed decisions in your quest for health (so far I have blogged concise summaries of over 1,500 scientific studies and have had three books published).

My research is mainly focused on the effects of cholesterol, saturated fat and statin drugs on health. If you know anyone who is worried about their cholesterol levels and heart disease, or has been told to take statin drugs you could send them a link to this website, and to my statin or cholesterol or heart disease books.

David Evans

Independent Health Researcher

Saturday, 6 August 2011

High intake of soy foods is associated with low sperm concentration

This post includes a synopsis of a study published in Human Reproduction 2008 Nov;23(11):2584-90

Study title and authors:
Soy food and isoflavone intake in relation to semen quality parameters among men from an infertility clinic.
Chavarro JE, Toth TL, Sadio SM, Hauser R.
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.

This study can be accessed at:

The study examined the association of soy foods and soy isoflavones with sperm concentration. The intake of 15 soy-based foods in the previous 3 months was assessed for 99 male partners of subfertile couples who presented for semen analyses to the Massachusetts General Hospital Fertility Center.

The study found:
(a) Men in the highest category of soy food intake had 41 million sperm/ml less than men who did not consume soy foods.
(b) Results for individual soy isoflavones were similar to the results for soy foods and were strongest for glycitein.

Chavarro concluded: "These data suggest that higher intake of soy foods and soy isoflavones is associated with lower sperm concentration."