The ONS Life Expectancy calculator is one of my favourite websites. Whilst others are looking at Facebook or Instagram, I’m busy comparing life expectancy figures. The simplicity of the site is great – you put in your age and gender, and the ONS tells you how long you are expected to live.
I read quite a lot of academic articles about longevity, and these have consistently told me that, if you live in the South-East of the country and you are affluent, you tend to live longer than the average.
What I do regularly hear from my clients is that their personal life expectancy is higher because “long life runs in the family”. This seems to be borne out anecdotally – if your parents lived longer than average, then it seems more likely that you will too.
Unlike me, you probably need to have good genes from both parents for this to be the case; my sisters and I are hoping to have got the life expectancy gene from our Dad (who is still having a great time at 91, though he has given up work now!).
Genetics does have an influence, and the effect is there to see when comparing species. Some species of mayfly only live for five minutes whilst the Greenland shark can live to 400 years old.
However, it turns out that academics generally agree that genetics aren’t the biggest influence on the difference in longevity amongst humans. The consensus, if there is one, is that genetics accounts for about 25% of the variability of lifespan amongst humans; that’s not insignificant, but it’s not the biggest factor. Added to that, it seems likely that family members teach each other lifestyle habits, and this masks the genetic factors.
Scientists think (but they don’t all agree) that a high amount of an enzyme called telemorase will result in fewer of your cells aging (telemorase affects a section of DNA at the end of each of our chromosomes – a bit like the plastic bit on the end of your shoelace – and this helps to reduce the ageing of cells).
However, lifestyle has at least as much of an effect. In Italy life expectancy went from 29 years in 1861 to 82 in 2011 – there was a big change in Italian lifestyles during that time, but no change in Italian genetics.
Lorna Harries of the University of Exeter puts it succinctly “Genetics can set you up for a long life, but you then need to do the right things to realise that”. As the change in Italian life expectancy shows us, a good lifestyle can have a much bigger impact than inheriting the right genes.
Philip Wise | firstname.lastname@example.org
Managing Director and Chartered Financial Planner