Just came across this 2003 article from BBC News that brings us the good news about male masturbation:

Men could reduce their risk of developing prostate cancer through regular masturbation, researchers suggest.

They say cancer-causing chemicals could build up in the prostate if men do not ejaculate regularly.

And they say sexual intercourse may not have the same protective effect because of the possibility of contracting a sexually transmitted infection, which could increase men’s cancer risk…

Men who ejaculated more than five times a week were a third less likely to develop prostate cancer later in life.

Keep up the good work, boys!