A human's lifetime is expected to eventually reach 150 years or more but will we be healthy enough to enjoy our old age, asks Haydn Shaughnessy
Overloaded by scenes of disaster on the autumn television screens, my children have been expressing an early fear of their own deaths.
My own recollection of that fear was that it arrived much later in life, adolescence even, but times are changing and the burden of mortality has begun to fall on the young.
Old age too is assailed with doom. No pension beyond a meagre €10,000 a year from the State, Social Affairs Minister Brennan recently warned community groups. Around 900,000 Irish people will be left in poverty if, of course, they survive the ravages of degenerative disease.
The sense of foreboding that we bring to age and mortality is, according to experts in the field, ultimately misplaced.
Age scientist Aubrey De Grey, of the University of Cambridge in England, believes that enough is known about ageing, and has been known for over 30 years, to reverse the process in the very near future.
"I don't think that any of the more exotic supplements currently becoming fashionable will add more than a couple of years [ if anything] to lifespan and I'm also pessimistic about getting appreciably more than that from caloric restriction [ eating substantially less - the best current bet for extending life].
"In short: living and eating the way your mother told you to is pretty much all there is right now," says De Grey, adding that in 25 years' time, however, this will have changed radically.
We could then be looking forward to lifespans of 150 years and above. Though we may think of extreme age as a science fiction nightmare, its significance, according to De Grey, is that "a cure for ageing is de facto a cure for age-related diseases".
And age-related diseases are the big ones, such as cancer and diabetes.
If De Grey's prescription sounds extreme, age management specialist Dr Alan Mintz argues that while, as yet, we can't affect ageing much at the cellular level (in the sense that we can't postpone it) we do know how to create and sustain a much higher quality of life for longer.
Mintz, who runs the Cenegenics Age Management Institute, in Las Vegas, Nevada, says: "We start to lose quality of life at around 35 but people have a choice where they put their money. Do they put it into a Mercedes or into the quality of their own lives?"
Mintz argues that an investment in healthy ageing is no gamble. He has 12,000 patients, many in Europe, though none that he could recall in Ireland. He too believes we are only 20-25 years away from some form of radical intervention in the ageing process but, in contrast to De Grey, he doesn't welcome it.
"The focus for me," he argues, "is not living longer but living out our lives in a productive way, with high quality.
"I believe in making way for the kids, let them have their time in the sun. A hundred years is enough. We are focused on having a much healthier and more vigorous experience of life from say 45 on."
Mintz puts at between 90 and 100 the age we can already aspire to live in robust good health.
The techniques are simple enough. Lifestyle, good nutrition, says Mintz, nutritional supplementation, exercise and hormonal supplementation, compensating for the gradual inadequacies of the endocrine system.
As the years pass we lose our ability to produce a variety of hormones in the appropriate quantities and Mintz is a believer in supplementing those flagging capabilities.
"We don't talk about hormone replacement," he says. "We supplement what is already there."
Dr David Wikenheiser is an age specialist with a preference for less intervention. He pitches the optimally healthy life at around 80 years.
"Ageing is accelerated by chemical, electrical and emotional insults to our bodies in general, and specifically our genetic code," he says, adding, "We're on the verge of a new era of optimal ageing because people are starting to believe that their lifestyle choices do actually affect their health.
"Scientists are proving that the lifestyle choices of diet, exercise and environmental exposures [ pollution] affect our genes and even how our healthy genes are expressed."
By "expressed" he means how those genes perform their allotted tasks.
Clearly, Mintz and Wikenheiser are talking about relatively simple, if, in the case of hormone supplements, still controversial, mechanisms that would allow us to look forward to our 70s and 80s in pleasant anticipation.
De Grey, however, wants an answer to why we feel so fearful and intimidated by the prospect of super-aged lives of 150 and more.
A society built on the successes of science, we seem to resist the lure of immortality, at least the pursuit of remarkably long lives that science offers, repelled perhaps by the fear that age is replete with disease. What, though, can it mean to "cure" age?
The ageing process is in part caused by mitochondrial damage (damage to the inside of our cells caused by excess free radicals created when we eat), by cell atrophy (the loss of growth hormones, the decline in cell division that, for example, exercise induces, but which theoretically can be compensated by stem cell technology), and a reducing capacity of telomeres, a part of the chromosomes that determines how many times a cell will divide.
Of course, there are other factors but, in short, ageing in this scenario is the byproduct of metabolism. That has to be a fixable dilemma, says De Grey.
Paul Murray of Age Action warns: "We are medicalising old age. Age is regarded as a health issue. The Department of Health takes the lead on care for the elderly, for example. Well, maybe that's wrong. Maybe it should be the Department of Equality and Law Reform."
One of the principal problems of ageing is arbitrary discrimination rather than health, he believes. According to De Grey, one of the biggest barriers to progress and much healthier, longer lives is a general attitude that degenerative illness, and the fear this entails, is somehow the price we pay for the lives we lead, or the "duty" we perform when passing the torch to the next generation. As individuals we fear both death and long life.
According to Wikenheiser: "Optimising ageing and remedying many degenerative diseases is available to each of us in our everyday lifestyle choices."
"The problem is that discipline and common sense are not glamorous, are often boring, and are essential to optimal ageing," he says.
Our policymakers, on the other hand, have still not got the hang of a society where life expectancy has increased from around 47 in 1900 to 78 in 2000.
We've accommodated a general expectation of exhaustion at around the age of 65, but have yet to address how our society might accommodate vibrant, creative and dynamic people in their 70s and 80s. Rather the opposite, according to Murray, we are wrongly fixated on their decline.