e mai uno che dica che la soia rende impotenti e soprattutto sterili i maschi.

We present the case of a 19-y-old type 1 diabetic but otherwise healthy man with sudden onset of loss of libido and erectile dysfunction after the ingestion of large quantities of soy-based products in a vegan-style diet.[...] Normalization of testosterone and DHEA levels was paralleled by a constant improvement of symptoms; full sexual function was regained 1 y after cessation of the vegan diet. This case indicates that soy product consumption is related to hypogonadism and erectile dysfunction. To the best of our knowledge, this is the first report of a combination of decreased free testosterone and increased DHEA blood concentrations after consuming a soy-rich diet. Hence, this case emphasizes the impact of isoflavones in the regulation of sex hormones and associated physical alterations.

This diet included a large amount of soy products equalling 360 mg of isoflavones per day. The diet consisted of soy milk, soy cookies (soy crisps), tofu, soy sauce, soy nuts, and soybeans (edamame)

A literature review recently published included nine studies with 252 subjects [16]. The highest exposure level in any of these subjects was 139 mg/d, whereas our patient consumed soy products that equalled 360 mg of isoflavones per day. The isoflavone intake threshold for symptomatic testosterone decrease might be higher than investigated in the nine studies reviewed.