Like the doctor in a corny joke, the study published last week by the Journals of Gerontology had some good news and some bad news.

The good news, say researchers from University College London (UCL) and Oxford University, is that people born in the 1940s and 1950s are living longer than their parents. The bad news is that they are more likely to be ill.

The study analysed data from the US, the UK and mainland Europe and found that people in their 60s and 70s experience greater multiple health problems, including obesity and diabetes, than the previous generation. But it would be wrong to assume that poor health is simply the price of a longer life.

According to the lead author of the study, Laura Gimeno, from UCL’s centre for longitudinal studies: “We find that there is a generational health drift, whereby younger generations tend to have worse health than previous generations at the same age.”

This unfolding health crisis has implications for the government, the NHS and society at large, but perhaps the people, other than the infirm themselves, most affected are those dealing with ailing parents and young children or teenagers – the “sandwich generation”.

It’s not a new demographic and its tensions have been well captured in films such as Little Miss Sunshine, in which the sandwiched family was sandwiched in a VW camper van.

The term was first popularised by US sociologists Dorothy Miller and Elaine Brody in 1981. Miller wrote of “adult children” who were exposed to “a unique set of unshared stresses in which giving of resources and service far outweighs receiving them.”

In the past four decades, however, those unshared stresses have steadily grown across the developed world as people live longer and with greater infirmity.

The declining health of older generations has coincided with more parental demands such as the spread of attention-rich “gentle parenting”, the rise in anxiety and depression among teenagers, and the delayed departures from the family home of children in their 20s.

One poll estimated that 6 million Britons now consider themselves to be in this sandwich generation. Increased longevity has also added another designation to the social menu: the four generation “club sandwich”, in which the 40s-60s may have some economic or care responsibility for their children, grandchildren and parents, or alternatively the 20s-40s may be in a similar position with their children, parents and grandparents.

David Goodhart, the head of demography, immigration and integration at the conservative thinktank Policy Exchange, has just written a book entitled Care Dilemma: Caring Enough in the Age of Sex Equality. His thesis is that family obligations have been disproportionately borne by women, but that greater equality has led to a deficit in care, and an ever-increasing and more costly role for the state.

He argues that the solution is not “to push back against equality but to raise the status of care, a realm that has traditionally been female”.

To many women, it’s a realm that remains stubbornly female. As one middle-aged woman carer of elderly parents says: “It is always the daughters who are expected to care, unless there are no daughters, in which case it will generally be the sons with a lot of support from their wives.”

Annalisa Barbieri, the Guardian’s family agony aunt, says the picture that emerges from her correspondents is of men who tend “to absolve themselves of responsibility, either by moving away or just not being emotional about it”.

Goodhart accepts that total equality has yet to arrive, though he points out that the share of domestic labour has shifted from 70:30 25 years ago to 60:40 today. But he maintains that his argument is really about reordering of society’s priorities to liberate women and men to play more active and beneficial roles as carers.

“If we valued care work in the home and the public economy more we would make it easier for one parent to stay at home, at least while kids are preschool – something which is very popular – but such valuable care work tends to be associated with women’s past, not their future,” he says.

To critics who find talk of enhanced family stability a conservative argument that amounts to a return to traditional roles, Goodhart believes that empowering women to be able to combine motherhood and work less stressfully, and the reduction in child poverty that unified families provide, should be “an idea that liberals support”.

Family therapist Jennifer Achan says that while there is a gender ­disparity in society at large, most of the clients who come to her with multigenerational issues happen to be men: “It’s usually because they’re struggling with their marriage as a result of splitting their time between their family and caring for a parent, or their mother moving into the family home and the wife not being happy.”

Laura, a 50-year-old who has three teenagers, is one of three sisters sharing responsibility for an ailing 91-year-old father who lives 90 minutes’ drive away (the names of interviewees have been changed).

“It becomes a little bit: ‘Why can’t you go over there? I did the last two times,’ ” she says of the resentments that can form around parental care. “But you have to get over that and realise that people are doing what they can.”

For Philippa, who is in her mid-50s, getting over it has proved to be a challenging task. She felt abandoned by her brother when their mother started to show signs of dementia. “He responded to her cognitive decline by moving to the other side of the country, leaving me to care for our mother,” she says, still smarting at the memory. “It’s been so hard, I can’t even describe it.”

As Tolstoy’s famous dictum about unhappy families implied, intergenerational dynamics are complex and infinitely varied. But if every struggling familial setup is unique, some are more unique, as it were, than others.

Take, for example, the case of Michael, a 60-year-old builder and writer living in Devon. He has a one-year-old daughter with his partner, who both live in Belgium, a 20-year-old son from a previous marriage studying at university and an 87-year-old father in Derbyshire.

“My father is fiercely independent but when my mother died five years ago, his drinking, which had always been heavy, began to become a bigger problem,” he says.

On a visit to see his suspiciously uncommunicative father, Michael discovered bank statements littered around the house that showed strange online expenses. Further investigation revealed that the octogenarian had been buying items for an online “girlfriend” and spending large sums of money on pornography, chatlines and women’s underwear.

“He was being manipulated and had spent 20 grand in two months,” says Michael, who was forced to gain power of attorney to pull the plug on these unaffordable credit card sprees.

While he recognises the inherent complications of having such a geographically and chronologically diffuse family, Michael says that all but one part of it works well enough. The problem is the anxieties that part provokes are not easy to contain.

“My dad is the biggest worry because everything is a struggle with him,” says Michael. “We’ve approached it from every way, tried love, understanding, anger – and now there’s a feeling of despair.”

Although Michael’s relationship with his Finnish partner in Belgium remains solid, Achan says that many couples reach burnout and then break up as a consequence of the pressures of dealing with children going through development stages, while having to look after parents.

The whole issue of care is one that within the family context is fraught with guilt and shame, which by their nature are private and often well-guarded emotions. Rare is the parent who isn’t severely tested by the job of rearing children, but the large majority are in it for the long run.

The option of not caring for a parent, or just resenting the care, is far more available, even if it takes an emotional toll. “My mother tells a lot of people that I abandoned her,” says Philippa, “even though I moved her to a nursing home near me and visit her every day. I feel really guilty. So there is no satisfaction, no feeling that you’re making somebody’s life better.”

For Emma, a 59-year-old divorced mother of four children, who are all still at home, the guilt comes from her mother’s resistance to help. Emma has asked her mother to move in with her several times, but the 90-year-old is adamant that she doesn’t want to be an imposition.

“When I drive past her house and see her sitting in a chair on her own, it poleaxes me,” she says.

Yet a further divisive strand of this knotted issue is the prospect of assisted dying becoming legal in England and Wales. Although the law would be restricted to very specific cases of terminally ill people, it could, say opponents, inadvertently encourage elderly people to see themselves as unnecessary burdens.

Perhaps the one point thatall interested parties can agree upon is that all forms of care – for young and elderly people – have been neglected by us as a society, pushed to the margins or back into private settings, where all the accompanying anguish and frustration have been left to fester.

Whether or not one agrees with Goodhart’s social perspective, it’s hard to dispute that our attitudes and practices relating to care are due for a radical overhaul. We have to rethink the needs and dignity of people at all stages of life, to humanise these most human of situations. No one should be the meat in a demographic sandwich that is long past its sell-by date.