Is it possible to extend lifespans to, say, 120 years, or longer, asks Devangshu Datta.
There have been many stunning advances in the biosciences but the process of ageing remains mysterious.
Life expectancy has increased in most places due to better nutrition, improved hygiene and healthcare, buttressed by new medicines and genetic research that tackles previously incurable diseases and conditions.
The average person can expect to live longer, and maintain better health than in any previous era.
But can the longevity of the species itself increase?
Every historical era has produced the odd individual who lived 80-90 years, or longer, in times when average life expectancy was less than 40.
We can certainly hope that more people will attain longer lifespans.
Life expectancy across the EU exceeds 80 years, and Japan, Singapore and Switzerland are 85-plus. (India is 69).
But is it possible to extend lifespans to, say, 120 years, or longer?
Some people think so.
There are therefore, two related but different goals, for researchers and policymakers.
One is to create a policy environment where more people live longer, and remain healthier.
The other, more ambitious goal is to understand ageing, and reverse its effects to extend potential lifespan.
There are around 500,000 people aged 100–plus at the moment.
This number will roughly double in every future decade.
A statistical analysis in Science journal suggests there may be no obvious limit to lifespan.
Italian demographers Elisabetta Barbi and Francesco Lagona, and the Italian National Institute of Statistics, looked at the records of 3,836 people, aged 105 or older in Italy, between 2009 and 2015.
As we know, intuitively, as well as statistically, the risk of dying increases for every adult.
That is, a 21-year-old is slightly more likely to die in the next 12 months, than a 20-year-old, and that risk continues to rise with every year.
Oddly, this study indicates that the risk "plateaus" after 105 -- the risk of dying in any given 12 month period seems to stay at around 50 per cent after the age of 105.
This could be a statistical, or methodological quirk, or it could indicate some biological phenomenon where cell-repair processes balance off ageing effects.
The XPRIZE Foundation, which has supported space research and robotics, among other things, recently became interested in longevity research.
One of the XPRIZE Board members, Sergey Young, has raised $100 million for a Longevity Vision Fund.
This will invest in biotech startups, researching longevity-related areas.
Young believes lifespans can be increased to 200 years and that the technologies to enable this can be made available to over 1 billion people.
X-PRIZE founder, Peter Diamandis is more measured but upbeat in saying, "Adding 20 to 30 healthy years on a person's life is likely to be the largest market opportunity on Earth.
"The convergence of genome sequencing, AI and cellular medicine will enable breakthroughs that will make 100 years old, the new 60."
XPRIZE recently held a longevity conference and released a road map, which listed 12 areas, where breakthroughs or improvements could promote better health and increased life expectancy.
According to The Lancet, over 70 per cent of deaths are due to chronic age-related diseases.
The list includes cancer, Alzheimer's, heart disease, liver disease, etc.
The 12 listed breakthrough areas include:
- Creating big databases that collect real-time ageing data from individuals;
- Creating a list of universally accepted biological markers as a global benchmark for ageing research;
- Replicating and fine-tuning studies that indicate calorific restriction could prolong life;
- Tools or tests to provide early warnings of at least three ageing-related diseases;
- Any cycle of rejuvenation that works with animals;
- Postponing the emergence of at least three ageing-related diseases with broad-spectrum treatments;
- Analysis and insight into the capacity to process nutrients;
- A quantified "theory of ageing" that ties all the mechanisms of ageing together;
- And easy exercise systems, or biomedical systems that replicate the positive effects of exercise.
These are ambitious but understandable areas for study.
The three "science fiction" objectives are: First, "arresting ageing by completely stopping the ageing process for at least one year".
This would have to be demonstrated first on mammals and then on humans.
The second is creating a model of the human body which is detailed and accurate enough to replace experimentation with human subjects.
This could circumvent current restrictions on research, which could be of potential benefit but likely to be dangerous to the subject.
The third is "ageing circumvented: A method to move the brain -- with or without the entire head -- of one person to the body of another, or to a non-human vessel, for over a year, while maintaining conscious thought or (in the case of cryonics) demonstrating that consciousness can be recovered after a time".
Achieving this would effectively mean immortality.