Sex beyond reproduction

Health benefits

Sex has been claimed to produce health benefits as varied as improved sense of smell,^[28] weight loss, stress reduction, increased immunity, and decreased risk of prostate cancer.^[29]

Sex between cohabiting partners lowers blood pressure and reduces stress, according to Stuart Brody, professor of psychology at the University of the West of Scotland. Brody's team monitored 24 women and 22 men who were exposed to stressful situations, such as speaking in public and doing verbal arithmetic, and kept records of their sexual activity. The men and women who had penile-vaginal intercourse responded more positively to stress "than those who engaged in other sexual behaviors or abstained".^[29][30] A study by Keith Light of the University of North Carolina went as far as to find a link between "partner hug" and lower blood pressure in women.^[29][31]

Frequent sexual intercourse was held to reduce the risk of the common cold by Carl Charnetski and Francis X. Brennan of Wilkes University in Wilkes-Barre, Pa. These scientists linked frequent sexual intercourse (once or twice a week) to increased production of the antibody called Immunoglobulin A or IgA, which can protect the body from getting colds and other infections. They took samples of saliva, which contain IgA, from 112 college students who reported the frequency of sex they had. The students in the "frequent" group had higher levels of IgA than those in the other three groups, consisting of people who were celibate, had sex less than once a week, or had it "very often" (three or more times weekly). The other three groups had comparable IgA levels.^[29][32] Charnetski and Brennan had previously shown that exposure to elevator music has a similar effect on IgA levels.^[33]

"Sex is a great mode of exercise," according to Patti Britton, PhD, past president of the American Association of Sexuality Educators, Counselors and Therapists (AASECT) and currently host of the website "Your Sex Coach". She notes that thirty minutes of sex burns 85 calories or more. She concludes that 42 half-hour sessions, or 21 hour-long sessions, will burn 3,570 calories - sufficient to lose one pound.^[29]

"Boosting self-esteem" was one of 237 reasons people have sex, collected byUniversity of Texas researchers and published in the journal Archives of Sexual Behavior. Some subjects who already had high self-esteem said they sometimes have sex to "feel even better".^[29]

Sexual intimacy, as well as orgasms, increases levels of the hormone oxytocin, also known as "the love hormone" which helps people bond and build trust. Researchers from the University of Pittsburgh and the University of North Carolina at Chapel Hillevaluated 59 premenopausal women before and after warm contact with their husbands and partners ending with hugs. They found that the more contact, the higher the oxytocin levels. Oxytocin allows people to feel the urge to nurture and to bond. Generosity has also been credited and linked to a higher level of oxytocin. In addition, as the hormone oxytocin surges, endorphins increase, and pain declines. In a study published in the Bulletin of Experimental Biology and Medicine, 48 volunteers who inhaled oxytocin vapor and then had their fingers pricked lowered their pain threshold by more than half. The oxytocin released during orgasm also promotes sleep.^[29]

Men who have frequent ejaculations, especially men in their 20s, may reduce their risks of prostate cancer later in life. Australian researchers reported in the British Journal of Urology International that they followed men diagnosed with prostate cancer and those without. They found no association of prostate cancer with the number of sexual partners as the men reached their 30s, 40s, and 50s, but men who had five or more ejaculations weekly while in their 20s reduced their risk of getting prostate cancer later by a third. Another study, reported in the Journal of the American Medical Association, "found that frequent ejaculations, 21 or more a month, were linked to lower prostate cancer risk in older men, as well, compared with less frequent ejaculations of four to seven monthly".^[29]

During sex, pelvic floor muscle exercises known as Kegels offer benefits for women. More sexual pleasure is expected to result, strengthening of the area, and help to minimize the risk of incontinence later in life.^[29]