Sex Changes (Everything)

Menopause, which typically occurs between ages 45 and 50, is unique to humans, for which there’s a good evolutionary reason: by age 50, a mother is beginning to experience many of the adverse effects of aging. She enhances her genetic contribution to future generations if she stops having babies of her own and thereby increases the likelihood that she’ll survive to raise her children and assist with her grandchildren.

Menopause happens gradually: 10 or more years before they cease menstruation, women may experience briefer cycles. At age 30, women typically get their periods every 28 to 30 days; at age 40, every 25 days; at 46, every 23 days. After age 35, women’s eggs are more genetically defective; if fertilization occurs, the babies produced are more likely to have birth defects. The follicles stop obeying orders from the brain to make estrogen. The amount of estrogen, especially estradiol, the most powerful estrogen, becomes scarce.

As women lose estrogen, their pubic hair becomes more sparse, the labia become more wrinkled, and the skin surrounding the vulva atrophies. The cell walls of a woman’s vagina become weaker and more prone to tearing; the vagina gets drier, more susceptible to infection, and—with loss of elasticity—less able to shrink and expand, less accommodating to the insertion of a penis. (Mickey Rooney on Ava Gardner: “She was unique down there, like a little warm mouth.”) In postmenopausal women who aren’t receiving estrogen, the vagina becomes smaller in length and diameter. Women’s breasts sag and mammary gland tissue is replaced by fat, which aggravates the sagging and is accompanied by wrinkling. The nipples become smaller and get erect less easily. Stretch marks in the breast grow darker. Fat accumulates in the torso, especially near the waist, neck, arms, and thighs—which creates uneven bulges, except in the face, which loses fat and creates a hollower visage. (A friend of Laurie’s told her, “At forty, a woman must choose between her face and her ass: nice ass, gaunt face; good face, fat ass.”) Women’s skin wrinkles, dries, and thins. Men have a thicker dermis than women do, which may be why women’s facial skin seems to deteriorate more quickly. Premenopausal women typically show no loss of bone density; postmenopausal women show a faster rate of bone loss than men of comparable age.

For women ages 20 to 40, vaginal lubrication after sexual arousal takes 15 to 30 seconds; for women 50 to 78, it takes 1 to 5 minutes. For younger women, the vagina expands without pain during arousal; for older women, there’s a limit to the expansion. Increased blood flow causes the labia minora in younger women to become red; in older women, there’s no reddening. For younger women, the clitoris elevates and flattens against the body; in older women, this doesn’t happen. For younger women, during orgasm, the vagina contracts and expands in smooth, rhythmic waves, usually 8 to 12 contractions in approximately 1-second intervals, and the uterus contracts. For older women, there are only 4 to 5 contractions, and when the uterus contracts, it’s sometimes painful. Older women return to a pre-arousal state much more rapidly.

When men turn 40, the tissues in the back of the prostate gland atrophy and the muscle degenerates, replaced by inelastic connective tissue. A hard mass sometimes appears on the prostate, causing men to produce less semen and at a lower pressure. For many men, the gland cells and the connective tissue in the middle of the prostate overgrow, causing pain during urination. Enlargement of the prostate gland occurs in almost all men, including my father (who had prostate surgery at 85), and the hormone changes that accompany this enlargement can result in various diseases, including cancer. Rates of testicular cancer peak in the 30s, then decline sharply. More inflexible connective tissue grows on the surface of the penis, whose veins and arteries become more rigid. With the reduced blood flow, men find it increasingly difficult to produce and maintain erections. One physician calls the brief, violent upsurge of sexual desire in old men the “final kick of the prostate.”

Men ages 20 to 40 need 3 to 5 seconds to achieve an erection when stimulated; for men ages 50 to 89, it takes 10 seconds to several minutes. Younger men quickly feel the need to ejaculate; older men feel less of a need to ejaculate, even over several episodes. For younger men during orgasm, the urethra contracts 3 to 4 times in one-second intervals; semen travels 1 to 2 feet. For older men during orgasm, the urethra contracts 1 to 2 times; ejaculation is 3 to 5 inches, with less semen and a smaller amount of viable sperm. The proportion of immature sperm increases over time. Young men return to a pre-arousal state in anywhere from a few minutes to a couple of hours, in two stages; older men return in a couple of seconds, in a single stage.

On the upside: the oldest verifiable father was 94 at the birth of his last child; the oldest mother was 66.

On the upside, somewhat more viscerally: my father, at 70, telling me a couple of years after my mother’s death, “I’ve been more active this year with Sarah [his new paramour] than I’d been the previous twenty-five with your mother, and I don’t mean once a night. I mean two or three times a night most every night of the week and then again in the morning.”