Sheree Russouw
Sarie Nortman’s four children stare at her in quiet admiration as she bakes yet another cake, works out on her exercise bike, nurtures her vegetable garden and happily consents to working overtime at her job in Germiston. Somehow, she still finds the time, and the seemingly boundless energy, to take care of her disabled husband. “Being busy just keeps my brain active. I prefer to be on the go than to just to stay in bed and moan about how old and tired I feel.”
The 66-year-old is a vital part of the longevity revolution pioneered by Professor Tom Kirkwood, the head of the department of gerontology at the University of Newcastle in Britian. “Today’s older people are the vanguard of an extraordinary revolution in longevity that is radically changing the structure of society and altering our perceptions of life and death,” he says in his book Time of Our Lives.
The United Nations Division for Social Policy and Development says that while global communication is shrinking the world, global ageing is maturing it. Indeed, Kirkwood’s revolution has been spurred on by a worldwide demographic change. Only 100 years ago 1% of the world’s population was aged 65 and older. It is estimated that by 2050, the world will be decidedly greyer with one in five people including those living in developing countries 65 or older.
According to Kirkwood, we are heading towards a “brave old world”, where people must adopt new attitudes towards old age. He says that ageing is “neither inevitable nor necessary”.
The UN echoes Kirkwood’s view, saying that ageing is not a separate issue but rather one integrated with social integration, gender advancement, economic stability and issues of poverty. “Ageing has developed a connection with many global agendas and will play, increasingly, a prominent role in the way society interacts with economic and social-welfare institutions, family and community life and the roles of women,” says the UN.
Such views run counter to the traditional Western notion that old people are meant to spend the rest of their days in retirement homes.
Kirkwood believes that providing elderly people with choices is fundamental. “Treating old people as weak spirited because they are frail does them the same terrible injustice that is often done to disabled people,” he says. “Prejudice about old age must not be allowed to force a premature closing down of the freedom to choose, particularly when the nature of old age is being changed by the longevity revolution.”
The oldest person is believed to have lived until the age of 122. The good news for aspirant centenarians is that Kirkwood believes that humans may live past this record in the future. However, he is dismissive of the ideal “fountain of youth” because he says there is no quick fix for the ageing process.
“People mistakenly believe that it’s just going to be a matter of a few years before scientists discover some genetic switch that can be thrown [to prolong life], some magic substance that will make us live for 200 years. The reality is that while science will increase our understanding of the ageing process dramatically, and allow us to make some very real improvements in the quality of life at later ages, it’s going to be extremely difficult to postpone this complex process that attacks us on many fronts,” he told the BBC in a radio interview last year.
Since 1977 Kirkwood has examined the role of DNA in ageing. He believes the process by which DNA gets hit, damaged and repaired is what causes ageing. Recent research has revealed that simple organisms such as fruit flies and nematode worms have a range of gene mutations that markedly affect length of life.
But Kirkwood maintains that it is highly unlikely that the genes for ageing will be discovered. Genes account for only about a quarter of what determines individual length of life.
“The genes we should be looking for are not ones that make us age, but rather the genes that keep us alive. We age because our genes, evolving at a time when life was ‘nasty, brutish and short’, placed little priority on the long-term maintenance of our bodies. As we get older we become more likely to fall prey to any of a number of diseases that might ultimately kill us, like cancer and heart disease.
“So, understanding the relationship between these diseases and what we might call the normal ageing process is one of the great challenges. Although individual diseases might be distinct clinical entities that require a particular course of medical treatment, there’s a very strong overlap between the kinds of molecular damage that leads to the overall ageing process and that leads to increased vulnerability to these particular diseases as we get older.”
He is certain there is no death gene to inhibit population growth. We are programmed for survival and our cells are not programmed to die. “What we know is that we don’t have some built-in genetic mechanism that programmes how long we will live and turns on something that will kill us.
Instead, what makes us age is the build-up of damage within the cells and organs of our bodies as we live our lives.
“So we actually need to look in close cellular and molecular detail at the processes that produce ageing or age-related disease. The turning point in the longevity revolution is to deal with degenerative conditions associated with old age.”
More than 2 000 years ago Aristotle grimly pronounced that ageing and death were the result of sexual activity. Kirkwood says that while there is no evidence of a link between sexual activity and ageing, there is a profound link between sexual nature and the way we age.
“The body is divided into cells that are designed for reproduction and those that make up all the other organs. From an evolutionary view point, there is a much greater need to protect the reproductive cells than the others. Damage to reproductive cells would lead to extinction; but the body, once it has passed on its genes to a new generation, is expendable.”
This knowledge has the potential to provide insight into why we become frail, grow old and die. “Evolution, through natural selection, has put a premium on the sexual part of our make-up and has been prepared to allow our bodies to wear out,” he says.
This helps to explain why women live longer than men and also why women experience menopause. Menopause represents a definite evolutionary advantage, he says, and may reflect the fact that older women have an exceptional contribution to make towards the continuation of the species.
So are ageing and longevity governed by genetic factors? “There is the obvious fact that different species have different lifespans and where better to look for the underlying causes than their genomes?
“Longevity shows a statistical tendency to run in families and the lifespans of identical twins are more similar to each other than the life-spans of non-identical twins. But you can’t choose your parents. Nor can half of us choose to be women as women do live longer than men.”
So what is his recipe for a long life? “Genes for longevity do not simply count our days and then kill us. They endow us with a given level of protection against damage. How long we actually keep going is then strongly influenced by factors like lifestyle the foods we eat, the exercise we take and luck. We have to take responsibility for our bodies. We only get one body in life. We might as well look after it if we want it to reach old age in good shape.”
Professor Tom Kirkword will be talking on Ageing, Sex and Death on Saturday March 16