The benefits of getting older
[1] “Growing old is great – when you consider the alternative,” as the saying goes.
Welcome to the age of ageing. With more than 800 million people over 60 and more centenarians
than the population of Iceland (that’s about 329,000), the world is having to brace itself for the economic –
and social – consequences. From a deluge of diseases to sagging skin and the dulling of the senses, old age
[5] is beset with creeping failures, medical interventions, and low expectations. But can there be a silver lining
for those joining the grey brigade?
Growing old has been synonymous with bodily decay since ancient times. The Greeks had a
particularly dire view – many saw ageing itself as a disease. Yet the latest scientific research suggests
ageing isn’t a straightforward decline after all. As BBC Future has reported before, life peaks later than you
[10] might think.
When does old age begin?
The poet Dante believed old age started at 45. A survey of the British public concluded that it starts
at 59 – the older the respondent, the greater the number of years they considered old. But the United Nations
and most scientists define it as any age after 60.
[15] Fewer colds
It’s not just the brain that gets wiser with age. The human immune system encounters millions of
potential dangers every day. As the body’s police force, it needs to learn to spot the dangers. For this, we
produce unique white blood cells which are tailored to the molecular appearances of millions of different
invaders. When they recognise a foe they stick around, forming an “immune memory”. The next time it
[20] turns up, they help to rally a rapid response.
The immune system remembers past enemies, making colds easier to beat when you get older
(Credit: Science Photo Library)
John Upham from the University of Queensland says this memory can last a long time. “People who
have gone through various epidemics, their immune systems can remember the virus for 40 or 50 years in
[25] some cases. It does begin to drop off in your 70s or 80s, but there’s a bit of a sweet spot for people –
particularly from your 40s through to your late 60s and early 70s – where the immune system remembers
the viruses experienced over the years.”
This cumulative protection translates into fewer colds. While 20-year olds can expect to catch two or
three in a year, over 50s average only one or two.
[30] Other immune defences however, tend to weaken with age. The body produces fewer new white
blood cells, and they become sluggish. Aged immune systems also produce less antibodies – proteins which
stick to pathogens to help identify and eliminate them. But what if this could be life-saving? […]
Declining allergies
And there’s good news for those with allergies, too. While the ultimate causes of allergies are still
[35] hotly debated, all are mediated by antibodies. The main culprit is Immunoglobulin E and like all other
antibodies, its production diminishes with age.
Mitchell Grayson from the Children’s Hospital of Wisconsin says the older you get, the less severe
the symptoms are likely to be. “Allergic disease peaks in childhood and then seems to decrease throughout
late adolescence and into their 20s. In the 30s there is another resurgence until people get into their 50s
[40] and 60s when the symptoms tend to get less common.” [...]
(Disponível em: <http://www.bbc.com>. Acesso em: 3 nov. 2015.)
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