Why We Live Longer These Days, and Why You Should Worry

Increased life expectancy brings burdens as well as solutions.

Posted Jan 02, 2013

One of the most misunderstood statistical figures is life expectancy. We hear the phrase bandied about as a marker of how long we can expect to live. Today, we can feel very smug, as on a worldwide basis, we now live longer than ever before. I won’t bore you with a mass of data, but suffice to say that a baby born today has a life expectancy in the eighties. In comparison, a baby born in the mid-19th century had a life expectancy in the fifties.

The most naïve mistake a person can make is to assume that ‘life expectancy’ is the age at which you die, but this is incorrect.  One definition of life expectancy is that it is the age at which half the people born in the same year will have died. Life expectancy says nothing about how long an individual person will live. They could be in the 50% who die before life expectancy is reached, or the 50% who live longer.  Another definition of life expectancy is that it is the average length of time a person can expect to continue living. Again, this tells us little about an individual, since some people will live shorter than the average length, some longer than the average length.  But one thing is clear – life expectancy does not set an upper limit on how long you will live. It is important to stress this because people sometimes hold the quaint belief that in historical times, there were no old people. There were, but they were simply rarer than they are today.

In industrialised countries, for the first time in history, the majority of the population can expect to reach old age. In many countries, older people outnumber children and teenagers. And developing nations are rapidly catching up: with the exception of countries with severe HIV problems, the life expectancy figures are rising much faster than in industrialised countries, and will eventually catch up.

The principal reason for our increased life expectancy is very simple – we don’t die young. This sounds a very stupid thing to say, but it’s accurate. The reason why there are a lot more people living into old age is because a lot more of them do not die in the first few years of life from what used to be killer diseases such as measles, whooping cough and similar. In part this is because of mass vaccination, but increased standards of public sanitation, better housing, better nutrition, etc, also have played a major role. Bear in mind that in historical times, 50% of infants died before they were five years old. This same figure still holds for parts of the developing world.

Because more people survive childhood and what used to be the riskiest time for our health, more people will live long enough to reach old age. Indeed, the longer you live, the less the modern world can help your continued survival.  This can be neatly demonstrated by looking at historical differences in life expectancy at different ages. A baby born today has a life expectancy of three decades more than one born two hundred years ago.  But if you consider someone aged sixty today versus someone aged sixty in 1813, the difference in remaining life expectancy is down to about seven years. Okay, seven years is still a meaningful figure, but it is a lot smaller than thirty years. And as people get older still, the historical difference in remaining life expectancy drops and drops.

Why should this matter? After all, our life expectancy is not affected by how long our forebears could expect to live. This is perfectly true, but that is not why I presented these figures. As stated above, what the data tell us is that as we get older, the less the modern world can do to keep us alive. Modern living and medical care have removed a lot of the danger from early life, but they have not done the same to later life, or the historical differences in remaining life expectancy would stay constant and not diminish.  Instead, what we find is that having failed to claim us in early life, debilitating and deadly illnesses have waited patiently and now claim us in later life instead. Thus, we enter old age only to be confronted by arthritis, rheumatism, respiratory problems, cardiovascular illness, cancer, dementia, Parkinsonism, and all the other lovely things that can make later life such fun.

Let’s take one specific psychological example. Researchers often talk about there being an ‘epidemic’ of dementia. This can give the impression that there are more cases of dementia per head of population than there were in the past. This is not so, but because the older population is increasing and dementia is omnipresent in the older population, the absolute number of cases of dementia is doomed to rise.  

And here lies the problem. Who is going to care for the added number of cases, and how? As the older population increases, so the younger population diminishes in size. This means fewer adult children to care for parents, and with changes in work patterns, fewer stay at home women who traditionally were expected to assume the role of caregiver [please don’t flame me for sexism, I’m merely stating historical fact].  Placing older demented people in institutionalised care might not be the answer. Even in countries with a developed state welfare system, fewer younger people means fewer people working, and this means lower tax revenue to pay for welfare care.  And that’s just dementia …

Governments and health authorities routinely bombard us with advice on healthy living – don’t smoke, regulate your drinking, take exercise, be careful of fatty foods, eat lots of fruit and vegetables, cut down on your caffeine, etc, etc. All no doubt sane advice, though (with tongue in cheek) it occurs to this cynic at least that over the past thirty years, the medical profession has done a brilliant psychological operation in persuading the general public that if they get ill with anything, it’s their own fault for their choice of lifestyle.

Be that as it may, all this advice is intended to get more of us into old age whilst being a lesser burden on the health services. But as more and more of us reach old age, what is going to happen then? Arguably, as governments and health authorities have done so much to encourage us to become old, it is their responsibility to look after us when we get there. But we all know that is not going to happen. Even something as relatively simple as mandatory pension provision seems beyond most governments. So instead, we need to prepare ourselves practically and mentally for later life far more than we do.  As a new year’s resolution, I strongly urge all of you below retirement age to take a long hard look at how you will spend your later life. The deeper you put your head in the sand at that thought, the more you probably need to do it.

And with that thought I wish you a belated happy new year.