People ask me about sex and the immune system all the time, wanting to know if it’s good for their bodies or if sex is beneficial to the immune system.

I must admit the first thing that pops into my head is “The Pickle Gambit” episode of Larry David’s Curb Your Enthusiasm. In the episode, Larry’s friend’s golden-child nephew breaks his elbow in a freak pickle jar accident, which prevents him from masturbating and relaxing, which in turn turns him into a monster. Larry’s solution is to hire a prostitute he knows, because he needs some release from all that stress.

Whether you find the scene amusing, disturbing, or both, Larry’s premise is spot on: Sex and sexual release (orgasm) are some of the most relaxing activities that one can enjoy.

It isn’t just sex, however; hugging one another, petting a cat or dog, and strong relationships and socialization affect homeostasis because they de-stress us.

But let’s talk about sex first. There is plenty of evidence going back decades that having sex affects all aspects of human life and a vigorous sex life is good for your biological soul.

People who have had more sex (without resulting in sexually transmitted diseases or viruses) have more mucosal IgA antibody and fewer sick days at work. One prospective study followed college students into adulthood and showed that sexual intercourse and even masturbation enhanced the health of both men and women.

In addition, sexually active women in one study had less cardiac events later in life.

Sexual arousal and orgasm also induce an increase in what are called sympathetic activities of the nervous system as well as the enhancement of catecholamine, a hormone made by your adrenal glands that acts as a neurotransmitter and helps you respond to stress, as well as increasing amounts of the hormone prolactin, an immune stimulant from the pituitary gland in blood plasma.

In a 2004 study called “Effects of Sexual Arousal on Lymphocyte Subset Circulation and Cytokine Production in Man,” published in Neuroimmunomodulation, the effects of masturbation-induced orgasm on lymphocyte circulation and cytokine production were studied in young men. White cell and lymphocyte subsets were analyzed via a method called flow cytometry in which the cells could be labeled with certain kinds of markers and the types of cells like lymphocytes measured.

The study was exceedingly small, but the results were startling in that they noted a transient increase in adrenaline and prolactin because of the orgasm, which resulted in an increase in the number of white cells, in particular natural killer cells which are very potent antiviral lymphocytes.

Dr. Bob is the author of IMMUNITY STRONG: Boost Your Body's Natural Healing Power and Live to 100.