Sci-fi aside, how long will I live?
Living to 100 will soon become a routine fact of (long) life. Life expectancies have been rising by up to three months a year since 1840 and although gains in the UK began to slow in 2011, it is still estimated that more than half the babies born in wealthier countries since 2000 may reach their 100th birthdays.
It is an impressive increase: in the early 1900s, the probability of a baby reaching 100 was 1%. A newborn in the UK today has a 50% chance of living to 105. There were 3,600 centenarians in 1986. Today there are some 15,000.
You do not have to be a newborn to benefit from this trend of increased longevity, though. A 60-year-old in the west today has an even chance of living to 90 and a 40-year-old can expect to live to 95.
But the longevity boost is not done yet: it is generally agreed that the natural ceiling to human life is somewhere around 115. Others say that even without cutting-edge AI or other technological wizardry, we could live far longer. Opinion broadly divides into three groups: the “levellers” who say we are at peak lifespan now. The “extrapolators” who argue that technology and education have made their biggest leaps but can squeak us up to a ceiling of 120 before levelling off for good. And the “accelerators” – those determined to defeat ageing, who believe we are on the verge of major breakthroughs in scientific and technological research that will increase longevity, pushing us into the realms of immortality.
Why are we living so much longer?
Life expectancy has been increasing since we cracked infant mortality in the 19th century. Economy, technology, healthcare and education have all combined with vaccines, safer childbirth and medical advances in the care of stroke and heart attack patients to keep the relentless pace of increasing longevity going strong.
But the growth in life expectancy began to slow in 2011 in the UK and people live longer in more than two dozen other countries.
There has not been a big medical or health gamechanger in the past couple of decades. While some argue that we should celebrate the longest lifespans that humans have ever attained, others warn that illness and infirmity risk turning long lives into slow, miserable declines.
How to avoid this? How can I stay healthy for longer
In his essay on ageing, De Senectute, Cicero says there are four reasons why people write off old age: it stops you working, it makes your body weak, it denies you pleasure and every day is one step closer to death. Then he shows why each argument is wrong. “The old retain their wits quite well,” he notes, “so long as they exercise them”.
Dan Buettner coined the term “blue zones” for five regions he identified as having populations who live healthier and longer lives than others (they are Okinawa in Japan, Sardinia in Italy, the Nicoya peninsula in Costa Rica, Loma Linda in California and Ikaria in Greece). The diets of those living in these regions, he discovered, consist almost entirely of minimally processed plant-based foods – mostly wholegrains, greens, nuts, tubers and beans. Meat is eaten, on average, five times a month. They drink mostly water, herbal teas, coffee and some wine. They drink little or no cow’s milk.