The Centenarian Genome

The secret of living a long and happy life involves a combination of lifestyle factors backed up by good genes. How, though, does this work in practice? According to gerontologists lifestyle consists of four key factors; diet, exercise, psycho-spiritual and social. All these factors are important and the odd 60 a day smoker is just an anomaly.

Thomas Perls of the New England Centenarian Study (NECS) has attributed up to 70 per cent of longevity to non genetic factors. However genes do play a significant part in living to a hundred and beyond, it has been said. For example the chances of a sibling of a centenarian (or supercentenarian) living to a hundred and beyond significantly rises.

The study has also found that the children of centenarians have a far reduced risk (under a third) of dying of cancer and risk of dying from heart disease is reduced by a third.

There are places in the world known as longevity hotspots such as Okinawa in Japan which has 58 centenarians per 100,000 people. This is five times the level of some developed countries. Other such hotspots include Iceland and Sardinia.

It has been found that clustering of genes due to a lot of inbreeding in Okinawa for example, gives evidence of a genetic link for longevity. Interestingly, it appears that environmental factors such as wealth and education are less significant as people age and that genetic factors tend to take over.

Scientists have been able to draw conclusions about ageing from conducting studies of twins. Ten thousand pairs of identical twins in Scandinavia have been compared and it seems that the genetic factor comes into its own after the age of 60. Before that, individual twins have mainly independent odds of reaching a certain age. However, with identical twins over 60, if one twin has reached a certain age there is an increased chance of the other twin doing so too.

Genes do play a huge part in deciding longevity in particular FOXO3A which is more dominant in centenarians even more than 95-year olds. This points to the need for studying what is known as "The centenarian genome".

Scientists should be able to find out more about longevity as the number of centenarians increases. As they learn more they will isolate factors such as how lifestyle factors may influence physiological pathways and so find out how our lives may be enhanced and how we may remain independent and healthy as long as possible.

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