It’s difficult to isolate soya’s benefits conclusively:

Isoflavone can act either like estrogen in the body, or it's opposite.

Soya’s benefits depend on the type of soya we eat. The isoflavone content is higher in unprocessed soybeans, compared to processed soya foods. 

Soya has only been a common part of the Western diet for around 60 years. Soy products include soy milk, soy burgers and soy-based meat replacements, tofu tempeh, miso and soya sauce.

Soya doesn't affect testosterone levels in men. A review of evidence found that regular soya food intake was associated with an almost 30% reduction in the risk of developing prostate cancer.

Some research has found that the benefits that soya provides are mostly determined by a woman's ability to produce equol, a bacteria that around 30% - 50% of adults produce in their intestines after eating soy.

Soya contains a high content of isoflavones that have estrogenic properties. It means they act like estrogen, the primary female sex hormone, and bind to estrogen receptors in the body.