New U.S. study [1].
Leitzmann / Giovanucci (2003) killed zinc supplementation for many men [2].
That study associated doses above 100 mg with an increased risk of advanced PCa.
In general, one must be wary of creating a mineral imbalance when taking high doses of any single mineral.
From the 2003 Giovannucci paper [2]: "Supplemental zinc intake at doses of up to 100 mg/day was not associated with prostate cancer risk. However, compared with nonusers, men who consumed more than 100 mg/day of supplemental zinc had a relative risk of advanced prostate cancer of 2.29 ..."
In 2011, Giovannucci was part of a study of Swedish data (Epstein / Mucci) [3]: "High dietary zinc intake was associated with a reduced risk of prostate cancer-specific mortality".
The healthy prostate has an enormous appetite for zinc, as it does for citrate. The zinc protects the citrate from oxidation. Citrate is a significant component of the ejaculate.
PCa cells down regulate the uptake of zinc. So it's natural to ask if zinc is relevant after diagnosis.
A 2008 paper (Dubi / Hershfinkel, Israel) [4] convinced me that it might be worth supplementing with zinc citrate. I use 50 mg daily.
See also Hong / Kim, Korea, 2012 [5]. "Antiproliferative effects of zinc-citrate compound on hormone refractory prostate cancer". (Cell study.)
One reason to use some zinc is that it protects against cadmium. An irony, though, is that zinc & cadmium are often found together & that some supplements have high levels of cadmium. Zinc is cheap enough that one can afford to go with a reliable brand. One that tests each new batch.
And now we have Giovannucci again:
"We prospectively assessed post-diagnostic zinc supplementation in relation to prostate cancer survival among 5,788 men with nonmetastatic prostate cancer in the Health Professionals Follow-up Study (1986-2019)."
"During a median follow-up of 11 years, we documented 527 lethal prostate cancer events and 3,198 all-cause deaths. Fifteen percent of men reported zinc supplement use post-diagnosis.
"Compared to nonusers, post-diagnostic zinc supplement use was associated suggestively with a lower risk of lethal prostate cancer {18% less} and significantly with all-cause mortality {16% less}."
"The inverse association was mostly observed among men who used post-diagnostic zinc supplements of 1-24 mg/d (lethal prostate cancer: {45% less}; all-cause mortality: {23% less},"
"... while higher dosage did not show a lower risk."
"Conclusions: Post-diagnostic low-dose zinc supplement use among nonmetastatic prostate cancer patients was associated with lower risk of lethal prostate cancer and all-cause mortality."
[1] pubmed.ncbi.nlm.nih.gov/364...
[2] pubmed.ncbi.nlm.nih.gov/128...
[3] pubmed.ncbi.nlm.nih.gov/212...
