What is the evidence about this impossibility of abstaining from sex? It's ridiculous to compare the "need" for sex to the need for sleep and food, and the author must provide some actual evidence in support of this wild claim...

One just needs to look at the supposedly celibate Catholic priests.....

100% of the catholic priests are not celibate? Really? What's the evidence for that?

There is tremendous cultural (post sexual revolution) bias in this "physiological need for sex" claim. (And some of that bias is self-serving).

Actually, you could say the only reason vertebrates sleep and eat is to increase the chances of having sex that will make sure genes are propagated for posterity (give or take a few exceptions). Pretty much the entire field of biology would support the claim that sex is as necessary as sleep and food (for what it's worth, I think scholars know why vertebrates eat and have sex, but not why they sleep). Given the need, abstinence is really going against nature.

Sex is important for the species.

For an individual? Not so much.

If you don't eat or drink you die. If you don't sleep you will sleep anyway, and if forcibly prevented from sleep, you will have serious health consequences.

If you don't have sex, what happens exactly to the individual that can even remotely compare to what happens if you don't eat, drink, or sleep??

During their lives, most adults will be celibate for some periods of time, due to lack of a partner, illness, childbirth, etc. It might be unpleasant, but it doesn't kill.

A fair percentage of adults are celibate their entire lives, by choice or not.

moshi -

It is only a necessity if you are Hollywood celeb, like Michael Douglas, and addicted to it...

Sex is replaceable with masturbation though. You'll die is you try to live on water and air for too long. You'll also die if you don't get any sleep.