* Note: Adult content
Research tells us that women's sexual functioning declines after midlife, manifested by reductions in arousal and orgasm, and increases in sexual pain. This is linked to reports of reduced sexual activity and satisfaction in older women, which appear to confirm the myth that sex is only for the young.
But a longitudinal study from earlier this year challenges the idea that sex is only for young people, as well as raising questions about the biomedical model that underpins the idea.
Out of 602 women aged between 45 and 70 who participated in the study, the majority were still sexually active. And the strongest predictor of sexual activity was the belief that sex was important. Physical levels of sexual functioning were irrelevant.
Body and mind
Does this suggest that sex for women over 40 is all in the mind? The mind can certainly affect the body; believing sex is important has previously been found to be the strongest predictor of embodied sexual desire in older women.
Conversely, even when mid-life women report lowered sexual response or vaginal dryness, the majority still report sexual satisfaction. So making assumptions about women's sexuality based on clinical measures of sexual functioning is clearly problematic. Attitudes to sex are more important than biomedical changes.
Chronic illness - such as cancer, heart disease or diabetes - can affect older women's sexual functioning. In research my colleagues and I conducted on women with cancer, for instance, the majority reported reductions in sexual desire and response, as well as increased sexual pain.
But these women still wanted to engage in sex, and found new ways of being intimate. This included touching, masturbation, kissing and hugging, as well as use of sex toys and lubrication. Indeed, many couples reported that their sex life was better as a result. They spent more time having sex and enjoyed a sense of increased intimacy.
Enjoying an expanded sexual repertoire is not peculiar to people with cancer. One-fifth of women at midlife have reported to have a desire for non-penetrative sex.
The foreplay reminiscent of youth can bring a lot of pleasure, often lasting longer than sex focused on intercourse. It also helps avoid the sexual pain caused by vaginal dryness following menopause.
Medical interventions such as Viagra can provide a solution for some, but the other option is non-penetrative sex. Perhaps this is why women in lesbian relationships are less likely to report sexual changes as they age. They were never tied to narrow notions of sex as intercourse in the first place.
Being willing to change sexual activities, talking about sex and having a good relationship are major predictors of continued sexual activity at midlife and beyond. Professional support can also help.
The other solution to a waning sex life is relationship change: finding a new partner, feeling more positive towards your current partner, or adult children leaving home can rekindle a couple's sex life.
The increasing number of older women being treated for sexually transmitted infections reflects a surge in the sex lives of the newly separated. Absence of safe sex knowledge, combined with increased risk of sexual infections because of vulva and vaginal mucosa thinning, are the downside to this rekindled sex drive.
We've interviewed women in their 60s, 70s and 80s who still enjoy an active sex life. We've also spoken to women who feel great sadness because their sex life is over due to divorce or bereavement. Indeed, the absence of a partner is the biggest predictor of older women having no sex life at all.
Improved sex after 40 can be due to increased self-confidence, being less worried about the "small stuff" and having more time to focus on pleasure. Women who feel "sexy" in their bodies, and who have a lower BMI, report higher sexual activity.
The baby boomer generation invented the sexual revolution. So why expect these women to become asexual in their later years? The generation that brought us free love, the pill and guilt-free divorce is re-writing the rules on sex in later life.
As the boomers challenge myths about ageing and sexuality, they are a living testament to mind over matter where sex is concerned. The sexual body may change as we age, but pleasure and satisfaction can stay the same - or even get better.
Jane Ussher is a Professor of Women's Health Psychology, Centre for Health Research at University of Western Sydney. She receives funding from the Australian Research Council, Cancer Council NSW, National Breast Cancer Foundation, Prostate Cancer Foundation Australia, Family Planning NSW and Parramatta Community Migrant Resource Centre, for research on sexuality.