Learning
and staying in shape key to longer
lifespan, study finds
University of
Edinburgh
People who are
overweight cut their life expectancy by two months for every extra kilogramme
of weight they carry, research suggests.
A major study of the
genes that underpin longevity has also found that education leads to a longer
life, with almost a year added for each year spent studying beyond school.
Other key findings are
that people who give up smoking, study for longer and are open to new
experiences might expect to live longer.
Scientists at the University of Edinburgh analysed genetic information from more than 600,000 people alongside records of their parents' lifespan.
Because people share
half of their genetic information with each of their parents, the team were
able to calculate the impact of various genes on life expectancy.
Lifestyle choices are
influenced to a certain extent by our DNA -- genes, for example, have been
linked to increased alcohol consumption and addiction. The researchers were
therefore able to work out which have the greatest influence on lifespan.
Their method was
designed to rule out the chances that any observed associations could be caused
by a separate, linked factor. This enabled them to pinpoint exactly which
lifestyle factors cause people to live longer, or shorter, lives.
They found that
cigarette smoking and traits associated with lung cancer had the greatest
impact on shortening lifespan.
For example, smoking a
packet of cigarettes per day over a lifetime knocks an average of seven years
off life expectancy, they calculated. But smokers who give up can eventually
expect to live as long as somebody who has never smoked.
Body fat and other
factors linked to diabetes also have a negative influence on life expectancy.
The study also
identified two new DNA differences that affect lifespan. The first -- in a gene
that affects blood cholesterol levels -- reduces lifespan by around eight
months. The second -- in a gene linked to the immune system -- adds around half
a year to life expectancy.
The research,
published in Nature Communications, was funded by the Medical
Research Council.
Data was drawn from 25
separate population studies from Europe, Australia and North America, including
the UK Biobank -- a major study into the role of genetics and lifestyle in
health and disease.
Professor Jim Wilson,
of the University of Edinburgh's Usher Institute, said: "The power of big
data and genetics allow us to compare the effect of different behaviours and
diseases in terms of months and years of life lost or gained, and to distinguish
between mere association and causal effect."
Dr Peter Joshi,
Chancellor's Fellow at the University of Edinburgh's Usher Institute, said:
"Our study has estimated the causal effect of lifestyle choices. We found
that, on average, smoking a pack a day reduces lifespan by seven years, whilst
losing one kilogram of weight will increase your lifespan by two months."