Sex in the second half

Harvard Health Letter

Sex isn't just for the young. Research is showing that older Americans are sexually active.

The sexuality that's such a big part of our teens and young adulthood has more staying power than younger people usually recognize and can continue to spice things up well into old age. Results from a University of Chicago survey published in 2007 suggested that over half of Americans continue to engage in sexual activities well into their 70s. Now another batch of findings from a survey conducted by researchers at Indiana University suggests that 20% to 30% of long-lived Americans are sexually active into their 80s.

Both of these surveys are cross-sectional — snapshots of behavior in a given period — so making pronouncements about trends would be getting ahead of the evidence. Still, there's reason to believe that sexuality is assuming a larger role in American old age. Millions of men are now taking erectile dysfunction drugs like sildenafil (Viagra) or tadalafil (Cialis). Growing numbers of Americans are enjoying relatively good health in their 60s, 70s, and 80s, and, not surprisingly, the University of Chicago study found a close association between good health and sexual activity among older people.

Consider also who is getting old these days — the baby boomers, a generation that came of age in the 1960s and '70s when sexual mores were changing, and a demographic group that hangs on to its youthful ways.

But the "frisky seniors" story line can be overdone. Sexual activity does subside with age. Biological factors tug in that direction, as do social arrangements: older people, especially women, often end up single when a spouse or partner dies. The Indiana University researchers found that sexual activity with a partner is common among those in their 20s, 30s, and 40s, dips significantly for both men and women in their 50s and 60s, and then drops further once people enter their 70s.

Now suitable for study

It wasn't long ago that older people weren't included in studies of sexual behavior because they were seen as largely irrelevant to the topic: 59 was the upper age limit of a landmark study of American sexuality conducted in the early 1990s. The University of Chicago survey (the formal name is the National Social Life, Health, and Aging Project) went a long way toward rectifying the situation. It focused exclusively on older adults, including just over 3,000 Americans ages 57 to 85. The results, published in The New England Journal of Medicine in 2007, received a fair amount of attention and lent some legitimacy to the subject of sexuality of older people.

The Indiana University survey was conducted by the university's Center for Sexual Health Promotion, which grew out of the research efforts of Dr. Alfred Kinsey in the 1940s and 1950s. Kinsey, who died in 1956, is credited with being one of the pioneers of research into human sexuality, although revelations about his research methods and personal life have since tarnished his reputation.

Kinsey and his colleagues conducted their research with in-depth interviews; this generation of Indiana sex researchers used electronic questionnaires and the Internet. A total of 5,865 Americans, ranging in age from 14 to 94, were included in the survey. A parent or legal guardian had to give permission for a teen to participate. Computers and Internet access were provided to the participants who didn't have them.

Sophisticated sampling techniques are used in this kind of survey research to make sure the study volunteers accurately reflect the population's age, income, geographic distribution, and other attributes. But sex researchers can't overcome the problem of self-selection: the sort of people who agree to fill out such a questionnaire may not reflect the population as a whole, particularly when it comes to sexual behavior. There's also no way of telling whether respondents are telling the truth about their behaviors, although the Indiana researchers point out that the anonymity of their Internet-based research may tend to make people more, not less, truthful about taboo subjects. The University of Chicago survey depended on in-home interviews.

Church & Dwight Co., the company that makes Trojan condoms, funded the Indiana University survey, and condom use featured prominently in the initial batch of survey-based articles published in a supplement to The Journal of Sexual Medicine in October 2010. One of them focused on the 1,973 respondents ages 50 and older, a third of the total.

A statistical picture of the sexuality of older Americans begins to emerge from that article and the University of Chicago survey results. Here are some of the main points:

Sexual activity tapers off with age. Both surveys show a decline in sexual activity with age, although the drop-off isn't as steep as one might expect, and a significant minority (especially men) defies the trend. In the Indiana study, 35% of the men age 80 and older reported that they had intercourse with a woman a few times or more in the past year. In the University of Chicago study, 38.5% of the men ages 75 to 85 reported having sexual activity with a partner in the previous year.

Older women are less sexually active than older men. Both studies show that older women — even the "young old," in their 60s — are less sexually active than men of the same age. The gender gap widens as people get older. The University of Chicago researchers noted that the women in their study were less likely than the men to be in a marital or intimate relationship, and even more so with age, presumably because men tend to die at a younger age than women. Differences in the amount of sexual activity that occurs outside of a relationship contribute to the overall gender disparity. In the University of Chicago study, about one in 20 women who were not in a relationship reported being sexually active in the previous year, compared with about one in five men who were not in a relationship.

Partnered sex gets high marks. In the Indiana study, over three-quarters (78%) of the men ages 50 and over rated their most recent sexual experience with a partner as either extremely or "quite a bit" pleasurable. About two-thirds (68.2%) of the women in that age group rated their most recent experience with a partner that highly.

Masturbation is common. Most men (63%) and almost half of women (47%) in the 50 and over age group reported masturbating in the past year, according to the Indiana survey. As with other sexual activities, the percentage declined with age, although a significant number of those 80 and older indicated that they masturbated.

The University of Chicago survey found masturbation to be almost equally common among those in a relationship and those not in one.

Good health matters. The University of Chicago researchers found a strong association between good health and sexual activity, particularly among men. Diabetes seems to have a greater negative effect than either arthritis or high blood pressure on both genders, but especially on women. In the Indiana survey, a woman's evaluation of her last sexual experience did not vary with her self-reported health status.

Sexual problems are common. Half of those who participated in the University of Chicago study reported having at least one bothersome sexual problem. Among men, the problems included difficulty achieving and maintaining an erection (37%), lack of interest in sex (28%), anxiety about performance (27%), and inability to climax (20%). Among women, the common problems were lack of interest in sex (43%), difficulty with lubrication (39%), inability to climax (34%), lack of pleasure from sex (23%), and pain during sex (17%). In the Indiana survey, 30% of the women ages 50 and over said they experienced some level of pain during their most recent sexual experience with a partner.

The University of Chicago researchers also asked people whether they were bothered by their sexual problems. Men tended to be bothered by them more than women, although when it came to lack of interest in sex, the percentages were about the same: of those who had this problem, 65% of the men said they were bothered by it, compared with 61% of the women.

Sexual activity outside of a relationship is common. A sizable minority of the men (43%) and women (36%) in the Indiana study reported that their most recent partnered sexual activity was with someone other than a spouse or long-time partner. This "nonrelationship" partner category included casual or new acquaintances, friends, and "transactional" partners — people who engaged in sex in exchange for something, often but not always money. Women whose last sexual partner was with a nonrelationship partner reported higher arousal, less lubrication difficulty, and a higher rate of orgasm than women whose last partnered sexual activity was with a spouse or a long-time partner.

Many men take something to improve sexual function. In the Indiana survey, 17% of men ages 50 and older took an erectile dysfunction drug in connection with their most recent sexual experience with a partner. In the University of Chicago study, 14% of the men and 1% of the women reported taking medications or supplements to improve sexual function during the past year.

Age cuts both ways

So it's pretty clear: old age doesn't preclude sexual activity, although it also doesn't make it any easier. Men experience declines in testosterone, which adversely affects sexual arousal and desire. There are age-related changes to blood vessels and smooth-muscle tissues that can make achieving an erection more difficult. Chronic conditions such as diabetes and high blood pressure become more common in old age, and in many men, they adversely affect erections more than any of the strictly age-related changes. Women are also affected by chronic illnesses, in addition to changes related to menopause, which include reduced vaginal lubrication associated with lower estrogen levels.

But age and experience may also hold some advantages. For example, some research suggests that women become more comfortable asserting themselves sexually as they get older. Some men gain greater control over ejaculation. It's also easier now to overcome some of the physiological hurdles that occur with age. Men have the erectile dysfunction drugs. Women can use any number of vaginal creams and gels. In fact, the number of older people who are sexually active has doctors and public health officials concerned about unprotected sex and sexually transmitted diseases in the elderly. With sex comes responsibility, even if you're old enough to collect Social Security.