Flax seeds might be helpful, as they seem to act as 5-alpha-reductase inhibitors and improve benign prostate hyperplasia symptoms.
A randomized, double-blind clinical trial compared the effects of various doses (300 mg and 600 mg) of SDG on symptoms of BPH. This study found that levels of enterolactone and enteroldiol were significantly raised after supplementation, while prostate size was reduced (link). Notably, the authors conclude that the improvements in urinary symptoms from SDG were similar to those from androgen receptor blockers and more effective than 5-alpha-reductase inhibitors.
Soy isoflavones come to mind too, as androgens are a key component in prostate cancers. I remember reading that once the cancer is past a certain stage, androgen inhibitors stop working, as the cancer resorts to IGF-1 for growth. As someone already mentioned,
green tea might be helpful for prostate cancer - even in later stages. As far as I know, green tea is not a 5-alpha-reductase inhibitor (in fact, it seems to increase DHT in mice), so it must work through other mechanisms.
In the study, EGCG decreased the proliferation of both the androgen-sensitive and androgen-insensitive prostate cancer cells. The effect was dose-dependent. At the highest dose, the proliferation of the androgen-insensitive cells was decreased by 88.2% and 87.5%. Androgen-sensitive cell proliferation was cut by 59.7%.
That was an in vitro study, however, so it's difficult to say how much green tea one should drink to see an effect. But, as in the case of curcumin,
adding piperine increases the bioavailability dramatically.
