20 February 2021 | New Scientist | 47certain chemicals such as phenols and
phthalates, to smoking, air pollution, maternal
stress and to the mother being overweight.
Genes and prenatal conditions mean
that some people are born with telomeres
consisting of as few as 5000 base pairs – the
building blocks of DNA – while others have
as many as 15,000. Considering that adults
lose between about 30 and 50 base pairs of
telomeres per year, this represents a huge
difference at the start line.
That disparity can increase throughout
early childhood. Fast growth and rapid cell
replication mean that telomere length
decreases quickly in this period. However, the
rate varies enormously. From birth until the
age of 4, children can lose anywhere from
270 to more than 1000 base pairs of telomeres
per year. One reason for this variation may be
the adversity a child experiences. A recent
meta-analysis of more than 40 studies showed
that poverty, abuse and maternal depressionwere among the factors linked to faster
telomere shortening.
Where telomere length is concerned,
most of our cards have been dealt before we
finish primary school. Once we enter our
second decade of life, telomere shortening
slows. Thereafter, how our telomere length
compares with that of other people of the
same chronological age may not shift much,
according to research by Abraham Aviv at
Rutgers New Jersey Medical School and his
colleagues. His team measured the telomeres
of 67 pre-teen children and their parents and
ranked them in order of telomere length.
Fourteen years later, the ranking remained
unchanged for 90 per cent of them. “If you
are in the 90th percentile of the distribution,
you are likely going to stay there for the rest
of your life,” says Aviv.
Not everyone is convinced that our telomere
ranking barely budges over adulthood.
Nevertheless, many do agree that popular
methods touted to increase telomere length
are often based on little more than hype.
Despite what you might read online, for
example, meditating for 15 minutes each day
won’t make you five years younger, nor will
eating broccoli with every meal – although, >“ At birth, some
people’s telomeres
are a lot longer than
those of others”