Gran-on-grandad action may be one of the last taboos, but studies show that at least 50 per cent of people over the age of 70 are sexually active. We live in a world flooded with sexual imagery, but in Hollywood and on television, that imagery barely stretches to people over the ripe old age of 30. Why is there an assumption that the menopause transforms women into asexual beings? And, why, when people bring up the subject of sex and septugenarians, is the universal reaction, "uggh don't"?
Women over 65 are already the fastest growing segment of the population and when the baby boomers begin to hit pensionable age around 2011, the demographic will go through the roof. In Britain alone, the number of over 60s is set to rise from 11.5m in 2003 to a staggering 19.5m by 2031.
Present-day pensioners come from a generation for whom sex was something that was done, but seldom discussed, even among partners. But all that is changing.
At 68, Nancy Friday, author of the best- selling book about women's erotic fantasies, My Secret Garden, is a cheerleader of women's sexuality. "All of us have been programmed to begin thinking of ourselves as old when menstruation stops. I don't think the menopause in any way affects my sexual identity," she says.
Friday believes that after years devoted to reproduction and child rearing, women deserve a little indulgence. Currently she is a host of www.powersurge.com, a website for women in midlife who are worried about not being sexually desirable. Here, she argues that women should use the power and status that age often confers to attract members of the opposite sex; just like men do: "They're pudgy, their teeth are yellow, they're bald, but they wear that power... They emanate it."
Friday's theory raises an intriguing question: would a wealthy grandmother have the same pulling power as her male equivalent? But, leaving that aside, there are other indicators that older women are gaining in sexual confidence.
Barbra Streisand, who turns 63 in April, made a return to the big screen last week in Meet the Fockers. In the film she plays Roz Focker, a Miami- based sex therapist who enjoys a vigorous sex life, often involving the imaginative use of cream cakes, with her on-screen husband who is played by Dustin Hoffman.
Elsewhere, Still Doing It, a recent US documentary which explores the sex lives of a group or women aged between 67 and 87, offers some illuminating experiences. "My son is so horrified at the thought of me having sex," says one interviewee, voicing a universal concern. Another, Frances, 87, didn't meet the love of her life until she was 80. Despite breaking her hip and needing to move to a nursing home two years ago, she now enjoys a healthy sexual relationship. Ellen, meanwhile, was a model 1950s suburban housewife who put up with a sexually unsatisfying marriage for years. Now aged 68, she has found happiness and a new lease of live with Dolores, aged 70.
Sexually active seniors may represent a demographic that advertisers have been slow to catch on to. But drug companies, recognising a potential multi-billion-pound market, have done better. While Cialis, Levitra and Viagra are doing the trick for men's erectile functions, the pharmacological race to find an equivalent boost for the post-menopausal female libido is hotting up.
Weird as it may sound, it's testosterone levels in women that ensure a healthy libido. And by the time most reach their sixties, these are roughly half of what they were before the age of 40. In December the FDA denied Procter & Gamble approval for a new medication aimed at increasing female libido - the testosterone patch - because of lack of information about its long-term effects. But this is something, we can rest assured, they're working hard to rectify.
And that's not the only thing that is surely going to change, to cater for an ageing population who are no longer willing to spend their twilight years accompanied by nothing more kinky then their knitting basket.
Internet dating is one area with huge potential to milk the grey pound. And since sex is the only form of physical exertion that some people are willing to take, doctors will also be advised to encourage all their patients to remain sexually active. It's even possible, assuming the right position can be found, that an active sex life could be good for joint problems such as arthritis.
But the downside to all this is likely to be a continued rise in sexually transmitted infections. Already the figures in the UK make alarming reading. In 2002, the incidence of gonorrhoea rose by an incredible 500 per cent in men over 65. And the number of older people with HIV/Aids is also growing. One out of every 10 people diagnosed with Aids in the US last year was over 50.
Still, Betty Dodson, 74, isn't one to let stats like that scare her into submission. She met her 26-year-old boyfriend in cyberspace more than four years ago and has been living with him ever since. With the aid of lubricants, she continues to have regular sex with him and says that age has also increased her experience in giving and feeling pleasure.
Despite being brought up in Bible belt Kansas and educated to think of marriage in a white dress to a prince as the ultimate erotic fantasy, Dodson was fortunate enough to see the light while still relatively young. She had assumed, as many women of that generation did, that when she found no pleasure with her first husband, she was at fault. But in the 1960s, after reading the findings of psychologist Virginia E Masters and gynaecologist William H Johnson that all orgasms are centred in the clitoris with its 8,000 nerve endings, Dodson realised it wasn't her fault and promptly sought a divorce.
Since the 1970s, Dodson has been running sexual consciousness-raising groups for women. These days, she says, more and more women who are over 60 are turning up at her midtown Manhattan apartment for private lessons in the art of masturbation.
Meanwhile, 30 years after the publication of her erotic opus, Nancy Friday is working on another book about women's fantasies. This time there'll be a fair share of pensioners contributing. "We are the first generation of women to have lived through the birth of feminism," she says. "We have an empty blackboard on which we pioneers can write how we are going to invent an age of sexually powerful, menopausal women." n
To buy a DVD of `Still Doing It', visit www.still doingit.com; www.power- surge.com; `Meet the Fockers' is at cinemas nationwideReuse content