No effect of soy or isoflavones on estrogen or testosterone levels in men

• Meta-analysis of 41 studies
• Testosteron was measured in 1753 men,
• Estrogen 2 was measured in 1000 men
• SHBG was measured in 967 men
• Regardless of the statistical model, no significant effects of soy protein or isoflavone intake on any of the outcomes were found.

Reference:

Katharine E. Reed, Juliana Camargo, Jill Hamilton-Reeves, Mindy Kurzer, Mark Messina. Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies. Reproductive Toxicology 2020