Prostate Cancer Risk Elevated for Cyclists over 50

plateaued

Yikes!

http://www.pbs.org/newshour/rundown/study-shows-prostate-cancer-risk-rises-in-male-cyclists-over-50/

RekindledRose

On the other hand, there is a correlation between frequent ejaculations and a lowered risk of prostrate cancer. So men... get on that bike during the day and during the night... heh...

http://www.webmd.com/prostate-cancer/news/20040406/frequent-ejaculation-prostate

http://www.newscientist.com/article/dn4861-frequent-ejaculation-may-protect-against-cancer.html#.U79_aLGW9oA

http://www.harvardprostateknowledge.org/does-frequent-ejaculation-help-ward-off-prostate-cancer

... and the list goes on.

ekat120

So I just looked up the actual study, and my main problem with it (besides the self-report issue) is this: in the table for the prostate cancer analysis, they break down the number of cases per group of cyclists. Here's what they report:

.75 hrs/wk of cycling: 3/511 (so 3 cases of prostate cancer out of 511 respondents)
3.76-5.75 hrs/wk: 7/449
5.76-8.5 hrs/wk: 9/569
< 8.5 hrs/wk: 17/498

The vanishingly small number of cases makes it pretty much impossible to generalize the results. We're talking 36 cases of prostate cancer out of 2,027 men. And Google tells me that the population incidence is about 1 in 6, which would be 338 men in the current sample if they were "average."

Furthermore, the results are only significant for the > 8.5 hrs/wk group (which means no differences when comparing the 3.75 hrs/wk group--the reference group--to the 3.76-5.75 and 5.76-8.5 hrs/wk groups), and even within that group, the variability is really high.

Here's a link to the study: http://online.liebertpub.com/doi/abs/10.1089/jomh.2014.0012

I hope they do more rigorous research on this topic. In the meantime, I'll have to pass along the ejaculation info to my husband