Sexual health - Is ejaculation necessary / essential for health if not trying to create a new life?

Absolutely NOT.

The orgasm, yes, but the ejaculation, no.

I teach a mix of self defense and health sciences and I can prove beyond a doubt (to my students) that the orgasm is important for good health while the ejaculation, if too much too often, can be bad.

Anyone who has a deep understanding of human physiology will know that there are a vast amount of concentrated nutrients in the sperm and seminal fluid. Letting it out of the body by ejaculating is an instant loss and will cause the body to rob from the rest of the body to get enough of the nutrients to make more sperm and seminal fluid ... especially vitamin B12 from the vitrious fluid in the eyes (hence the saying "stop or you'll go blind"). While the orgasm is great for the health, the loss of fluid can be so bad that most religions have a celibacy rule so the religious leaders do not suffer from the adverse effects of sperm/seminal loss. Although the effects are not usually visible or detectable to the younger men, if the frequent loss continues for many decades, the effects become much more noticable, but by then, it is too late to fix the problem.

Taoism teaches people how to enjoy the feelings of the orgasm while avoiding the fluid loss problems. Check out the book, "Taoist Secrets of Love: Cultivating Male Sexual Energy" by Mantak Chia (or just google the man's name) ... or his follow up book, "The Multi Orgasmic Man" ... in them he explains exactly how to gain the internal self controls needed to maintain self control during orgasm. With most men, the orgasm results in a sensory overload and loss of control and then the ejaculation happens because it can no longer be controlled. With the male, orgasm and ejaculation are two completely separate events, they just happen so close together it is often assumed they are the same. Once a deep level of internal self control has been developped, the man may make a conscious choice of having sex that is either recreational or procreational.

The procreational sex definately need the ejaculation, but the recreational sex does not.