Peak life expectancy?

Life expectancy has peaked in some US States according to recent research. This follows research published in 2005 that suggests current living children may not outlive their parents, and that peak life expectancy in the US may be reached between 2030 and 2040. Mostly, this is attributed to the massive spike in childhood obesity which typically results in lifelong obesity and associated health problems.

In coming decades, as obese children carry their elevated risks of death and disease into older age, average life spans could fall by two to five years.

The map below shows areas of the US where life expectancy fell between 1987 and 2007 (in red). At first glance it seems that rural areas are overrepresented in falling life expectancy. There is usually is typically a strong inverse correlation between obesity and income, which would appear consistent, but also one could guess that more automation of rural jobs, and greater propensity of sedentary recreation activities (the internet etc), may be a contributing factor.

Since then more evidence of decreasing life expectancy is dripping into the debate, especially in the US. One recent study suggests that based on data from 2008, the latest available, life expectancy in the U.S. fell 36.5 days from 2007 to 77.8 years.

But the overall picture still looks very good. The below graph compares the growth in life expectancy in a selection of countries.

In Australia, life expectancy continues to grow, but there appears to be no similar geographical disaggregation studies showing the divergence between urban and rural life expectancy. The data below shows that men have gained 3.1 year of life expectancy at birth in the past decade, while women have gained 2.1 years

For me, the surprising thing in these data tables is that our life expectancy at birth is rising mostly due to the prevention of death earlier in life, not the extension of old age. If you make it to 85, you have only gained six months of extra life expectancy over the decade – around a quarter of what you gained at birth (one fifth for men).

The other trend of note is that men are catching up to women in the life expectancy at birth. Again, this concurs with the observation that early preventable deaths are being reduced, as risk taking behaviour is disproportionally male.

A couple of questions spring to mind. First, will the rising trend in life expectance continue in the rest of the world?  And is it possible that people compensating for improved medical care by being less vigilant about their health or taking more health risks?

When I watch extreme sports I often think that it could be a sign that we as a society have made life so risk-free that people need to compensate by pushing themselves near the limit. I would classify this type of risk as low probability but high impact.  Usually, we tightly regulate these types of risks, with seatbelts, helmets, fire alarms and other safety guidelines.

My suspicion is we have removed many high impact low probability risks only to compensated this loss of risk by taking on another type of risk with high probability, but low, or distant, impacts (in addition to the extreme sports variety of compensation).

Poor diet, bad exercise habits, and exempts of this second type of risk.  Smoking laws in Australia are probably the stand out example of regulation in this area, but even with all the well intentioned rules, they are the easiest risks to substitute for others. For example, a former smoker might find that chomping down a bit of chocolate is a good substitute for their addictive habit.

As a general trend we might be avoiding high impact risks by unknowingly substituting for low impact risks. Parents need to be especially aware of this. For example, cycling appears to be dangerous because of the need to wear helmets, so parent might be less inclined to encourage cycling. The same goes with sports where there is a perception of high risk, such as rugby or Aussie rules football. Even the most basic of actions such as walking to school is often seen through the high risk lens (due to the low probability of abduction) and a generation used to being dropped at the gate may be less likely to walk later in life, which is a risk itself.

I have no definitive answer to either question. My gut feeling is that medical breakthroughs will stay one step ahead of any compensatory behaviour, and that life expectancy will creep up ever so slowly. I also feel that life expectancies between countries will continue to converge. But I will be on the lookout for more evidence of a peak in life expectancy elsewhere, and should we see this case arising more frequently, I believe that the theory of compensatory behaviour will need serious investigation.

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Comments

  1. Diogenes the CynicMEMBER

    The analysis of micro factors is good here Rumple but what will happen if the Peak Oil scenario is right and we see a massive decline in oil energy inputs? Economic growth will be flattened or falling and life expectancies are likely to go the same way. Can we afford the sorts of medical technology costs you refer to under that scenario? Probably not.

    • If the Peak Oil crowd are right we are in for a very different life indeed. Over at The Automatic Earth they have long published primers for a post-oil existence that is strongly focussed on self-sufficiency together with small community lifestyle etc. You’re right under that scenario many technologies we take for granted may no longer be available.

      However, I for one do not rule out human ingenuity coming to the fore and entirely new technologies/energies being created. We are a most adaptive species (and in that sense I suspect Bjorn Lomborg is correct in his views as to how to deal with AGW).

      • I will write about peak oil soon. But in short, the economic importance of this absolutely certain physical event depends very much on the speed of the peak. A decades long flat plateau would not be as disastrous as a very sudden fall in possible output. There are also political interactions to consider, that are almost certain to destabilise the period.

        • You might find TAE articles an interesting adjunct to your peak oil research. Foss is a nuclear scientist by training, one switched-on individual.

      • > If the Peak Oil crowd are right we are in for a very different life indeed.

        Peak oil is certain – the peak oil crowd cannot be wrong.

        I suspect you are referring to the peak energy crowd. They state (and with good reason) that nuclear/renewable energy will not fill the gap left by falling oil output.

  2. Pretty sure I saw a paper a while back disaggregating urban/rural life expectancy in Oz and from memory urban lifespan was years longer.

    Also some years ago read a little book by Dr Dale Atrens (Sydney U), The Power of Pleasure wherein he gently debunked a range of guidelines relating to health, obesity and longevity – effectively arguing that a little indulgence is a good thing. Particularly liked his take on alcohol consumption where he compared the Oz 2 drinks a day message with the Italian and French 7-9 drinks a day! I adopt a more Euro outlook on that one.

    Generally, most things in moderation and remember to enjoy yourself. Certainly not a book for some of the more self-flagellating commenters at MB…

    • Sounds like my kind of book! The Oz/Euro comparison is like stock/flow (kind of). Most Euro’s I know drink regular amounts all the time, compared to Aussies that drink nothing from Mon to Fri then do it all Friday night and sometimes all Sat night..

      • darklydrawlMEMBER

        Yeah, from a health perspective a more constant (within sensible limits) level of consumption is far less harmful than nothing all week and a massive bender on Friday night and Saturday.

        I would agree that being happy and relaxed is far better for your health than stressing about too many things, including what you should and shouldn’t eat. All things in moderation is a fairly safe bet.

    • yes alcoholics live longer it s a fact but the brain suffers, my grandma is pretty much 100 and never drink water 😉

  3. Obesity in Australia is a real soap box issue for me. With the exception of people on psychiatric related medicine, certain South Sea Islanders (ie genetic reasons) and the relatively few people with genuine eating disorders, It’s purely due to poor eating practices. A lot of studies have pointed out the relationship between obesity & lower socioeconomic groups. This points the finger unerringly at poor diet, perhaps through larger families and having less time to cook well, and fast food. Unfortunately the condition is extremely pernicious as overweight leads to depression & lack of excercise which reinforces the eating compulsion, thus exacerbating the condition.

    Having said all that, I cannot help but feel prejudiced (rightly or wrongly) when I see the disadvantage being obese puts OTHER people to. I sat in a train the other day with two obese people taking up six seats. Listening to their conversation (rightly or wrongly), they were talking about frequent vists to hospital for various conditions, a lot of which I knew to be largely related to obesity.
    Obesity is the one and only human condition that the vast majority of people can cure through will power alone. Obesity is wrecking the public health service, taking beds and treatment away from children and adults who do take care of their health. It’s not just about shortening life expectancy, it’s about it shortening OTHER people’s life expectancy.

    Bring in the compulsory health camps!
    There, I said it, and [email protected]#$%r the political correctness.

    • or privatise hospital system fully and allow people to pay for their own actions, the rest of us shouldnt be subsidising bad behaviour

    • also how funny that thw western world is so wealthy (relatively speaking) that the poor are eating themselves to death

    • A poor diet is only one side of the equation – sedentary lifestyles push the calorie equation way out of whack beyond just the eating unhealthy part. Unfortunately, going to the gym or having access to facilities is also socio-economically biased towards the higher end.

      • Mark HeydonMEMBER

        “having access to facilities is also socio-economically biased towards the higher end”

        No matter what the socio-economic situation, almost everyone has a pair of shoes, shorts and a t-shirt – it’s all you need to run. It’ll get you fitter than anything I’ve ever seen anyone doing at a gym.

        The thing that’s often missing at the lower socio-economic end is self-motivation and perseverence. That’s much harder to solve.

    • +1 TSpencer & Karan
      I had expected a torrent of abuse from the PC end of the spectrum. Reasoned support, observation & criticism – MB blog scores again..

    • darklydrawlMEMBER

      I would also add Rob, that consuming vast amounts of the wrong food can lead to a condition where you are obese and (somewhat ironically) suffering from Malnutrition due to the poor quality of the food consumed.

      Indeed I know a family member whose attitude is similar to those you mentioned on the train. Always going off to the doctor for tests for things, many of which are seemingly diet related.

      I actually said to her, I am surprised the doctors don’t send you home and tell her “to come back when you have stopped smoking, started eating real food and lost 30 kilos.”

      Only then can they start to see if you have any real medical problems they can fix, rather than it being totally lifestyle related.

      At least that is my opinion.

  4. I can not see it as a peak in life expectency here, sorry.

    Obesity I doubt will be more than a medium term fad.

    There is much discussion on it with a plethora of causation theses, ranging from corporate conspiracies to the rise feminism, and everything in between.

    I personally have had a food revelation since I visited Paris in March and I have lost 11kg in 8 months to be close to ideal weight.

    Correspondingly, I doubt I will ever be overweight again, even though I now have more cream and butter in my cooking than ever before.

    The change has been an entire outlook, not a temporary diet to adjust my caloric intake for a short period.

    I do believe eventually, dietry health will be pronounced, and humanity will go on its merry way on ever increasing life expectency.

    • Well from what I observed and how it has worked for me;

      Smaller portions but better quality food.
      Animal fats are better than vegetable fats.
      No carbs after lunch.

      I do know different dietry habits work for different people, but the emphasis was on the quality and embracing it, rather than shovelling fuel down your htroat.

      • How about how much time you spend in a car vs. taking public transport? That made a massive difference (10kg) for me when I was in London.

        • I drive to work around 4 times a year. But that has been that way for the last 5 years.

          I have added in a 15 minute walk from the train station to work up a gentle hill, as opposed to a connecting bus dropping me in front of work. I also now fit in 4 x 30 minute light weight session.

          But a sign it was more to do with diet was for 6 weeks ago my son started day care, and consequently has been contracting infections all the time. I hadn’t done any exercise in those 6 weeks but still managed to lose weight.

          Now this differes greatly from me pre-Paris diet, with a considerable amount of rice and pasta for dinner, I’d exercise 50% more than I do now and I couldn’t lose weight.

  5. The life expectancy figures for Japan are dodgy. Many alleged centenarians actually died in their 80’s, but their children pretend they are still alive in order to keep collecting their pension. In reality, Australia may well have a longer life expectancy than Japan. The Japanese eat the best diet in the world, but too many of them smoke.

  6. An alternative (or perhaps supplementary) explanation to why life expectancy appears to be falling in many rural areas of the US is that these areas are sparsely populated and thus have much higher sampling error.