Why do older people get sick? It may seem like an odd question as surely the answer is that as we get older, it's just a biological reality that we'll develop some kind of disease or condition.

But how much of our health in older life is actually caused by things that were set in motion years ago -- even as far back as the social class we were born into, the education and career we've had and the community we've lived in?

Michael Marmot is the director of the UCL Institute for Health Equity (Marmot Institute) in the UK and the world's foremost expert on health inequality.

His influential book 'The Status Syndrome' explained how seemingly small differences in education, job title, income or even the size of your home can have a significant impact on your health and your mortality.

And when it comes to older people's quality of life and health, that impact is still as evident.

"The best things to have to get to older age are high status, wealthy parents, a good education, a good job and not being a smoker," says Marmot. "You might say 'nice work if you can get it' because some of these factors are out of the hands of people. But it is evident that a person's chances of staying well are clearly influenced by their social position."

Marmot is delivering a keynote address on the subject of health inequality in older people at the forthcoming CARDI (Centre for Ageing Research and Development in Ireland) conference in Dublin.

"One thing I'm going to say at the conference is that the inequalities in health that we see in younger people, we also see in older people.

"And secondly, I'm going to emphasise what is now becoming my theme song -- that inequalities in health don't just mean having the extremes of very good health and very poor health. There is a social gradient and that's really important.

Poverty

"Obviously there are older people living below the poverty line and we should be focusing on trying to get them above the poverty line. But there is a hierarchy at play which means that the further down the social gradient you go, the worse health outcomes you will tend to see."

Essentially the social gradient refers to a person's income, wealth, education and their social class (working, middle or upper class).

And Marmot's work was recently borne out by our own Irish Longitudinal Study on Ageing, which is following the lives of 8,000 people aged over 50, until the year 2018.

Its first set of findings released earlier this year show that people with higher levels of education and wealth enjoy better health outcomes in later life.

For example, those who are wealthier and better educated have the highest physical activity levels and the best quality of life is experienced by older people with the highest asset wealth.

But does this mean that we are all victims of fate and that there's not much we can do about it?

"I suggest taking a life course approach," says Marmot. "The problem is that people say it's all over by the end of childhood and the course is set. But this doesn't mean that by the time we get to older life, that we can't make any changes.

"Whether someone is living on reduced means is really important. In my review of health and inequality, I found that there was a minimum income required for healthy living. It's slightly old data now but I found previously that the state pension was insufficient to lead a healthy life. But in that respect, pensioners were not the worst off -- families with young children and particularly single parent families were the worst off."

Research

Marmot's research relates to the UK state pension rather than the more generous Irish one but the key fact is that the more income and, crucially, the more wealth a person has, the better their quality of life.

And when someone suffers a financial setback, such as the wipe-out of a private pension based on bank shares, it can also have an effect on health outcomes.

"Wealth provides a cushion for people in life and can give more optimism," says Marmot.

"Being in poverty, having a bad diet and a cold home can all contribute to a person's health. Another thing is social isolation in old age -- it can kill people.

"I think the question, 'Why do older people get sick?' is a very good question.

"How much can health inequalities be addressed by current circumstances -- fuel poverty, cold homes, inadequate transport, for example -- and how much can be addressed by a person's earlier life?"

The answer to this question can only come through long-term studies of health inequality -- following people throughout their lives.

It's the kind of work being pursued by the Irish Longitudinal Studies and by Marmot. He is currently working on the Whitehall II Study of British Civil Servants.

The original Whitehall Study followed 18,000 male civil servants over 10 years, beginning in 1967. It found a strong link between the grade levels of the civil servants and their mortality rates from a range of causes.

Workers in the lower grades of employment, such as messengers or doorkeepers, had a mortality rate three times higher than that of men in the higher grades. And again, there was a social gradient at play -- the higher up the scale, the longer one might expect to live.

The Whitehall II study is following some of the original participants, who are now between 60 and 80 years of age.

Inequality

Generally speaking though, most health inequality studies focus on people of working age and don't delve too much beyond.

A book which was released in 2009, 'The Spirit Level: Why More Equal Societies Almost Always Do Better', looked at children, for example, but failed to focus on older people.

However, it's worth remembering that as much as older people can be classed as a group, there are also huge differences in terms of their lifestyles.

"Older people are not a homogeneous group," sums up Eamon Timmins, spokesperson for Age Action Ireland. "But it is apparent that if you have a good income and education, it does help your quality of life.

"But as much as money will help get you a long way to ageing, it won't stop you getting cancer, dementia and lots of other illnesses."

Timmins says there is clearly a group of older people who don't have a safety net to fall back on.

"The older people who are most vulnerable are those with a low income, those who live alone, those who have poor health and those with less insulation in their homes.

"Fuel poverty is a reality for many older people and it's something that Age Action will be launching a campaign about. It's a particular concern if the weather is going to be as cold as the reports indicate

"Hypothermia is a concern but what will affect greater numbers of people are cardiovascular and respiratory conditions.

"Energy prices have gone up and pensioners' fuel allowance units have been cut. They either have to put their heating on less or have to find the money to pay for the costs.

"Last year we heard of some crazy situations that older people were in because of the bad weather. One lady was in touch with us to say that when the weather hit minus 12 in her house, she realised that she would become unwell because of it.

"She moved into the corridor of her house and lived there for more than a week -- it was warmer because there were no external walls."

As our population continues to age (by 2041, the number of people aged 75 or more in Ireland will reach almost one million, which will be three times the number of people that age living now), the question of long-term care will become even more of an issue.

"From a policy point of view, many older people's health needs are not really a matter of being hospital based -- we're talking about therapy, rehabilitation, community support, home help and also respite help for carers," says Eamon Timmins.

It's a topic that Dermot Kirwan, spokesperson for Friends of the Elderly, takes up.

"Many elderly people rely on public-funded home help, which can be just a couple of hours a week. An older person who can afford it can top up the publicly funded home help with a private home help.

"Having this extra help can sometimes mean the difference between being able to stay at home, with support, or having to go into a nursing home or hospital.

"And it's clear that elderly people who remain at home do a lot better overall than those who go into care."

Cutbacks

Kirwan says that cuts to the health service are affecting older people.

"Once the medical card kicks in, it is a help to older people on reduced means," he says. "But there have been cutbacks. For instance, treatment for dentures used to be free but now it's only free if the dental condition can affect the person's overall health.

"So if a person's dental plate goes, it could cost them around €150 to get it fixed.

"If the person can't afford it, they'll do without the denture plate and then they'll end up only eating mushy food, which isn't great for their nutrition."

He points out that older people without access to adequate transport only have a limited range of food options.

"Years ago, there was a corner shop that sold fresh fruit and vegetables on most streets. Nowadays, the symbol shops only carry a small range of fruit and hardly ever any vegetables. Most of the food they sell is processed foods.

"Older people who don't have a car can't pick which supermarket they go to -- they have to go to the shops they can walk to and these tend to be the symbol shops."

Interestingly, Kirwan points to two health advantages that people from working or lower middle classes may have compared to their counterparts with more assets and education.

"We get a lot of older women -- in their mid 70s into their 80s -- coming to our services in Dublin. They're aerobically fit because they never had a car. They're inner-city ladies who moved to the inner suburbs of Dublin and they walk in and out of the city centre every day with their shopping trolleys.

"They're also from a generation of women who didn't smoke or drink because it was frowned upon for women at the time -- their husbands did smoke and drink though.

"The other advantage I would see is that older people living in the inner city or inner suburbs can pop their head out the front door and talk to people.

"There's much more of a sense of community than you might find in the leafy suburban areas -- where there's a hedge and a wall around the front garden. If you live there, you could be very socially isolated."

The CARDI Conference, which is titled 'Ageing Globally, Ageing Locally', takes place on Nov 2 and 3 in Croke Park. For more information visit www.cardi.ie

Originally published in