Regardless of the huge strides scientists have made towards reaching the elusive goal, immortality remains a pipedream.

But one researcher in the anti-ageing field believe we could get there — or at least extend human lives beyond the current biological boundaries — without any miracle pill or injection.

Dr Alex Zhavoronkov, head of biotech company Insilico Medicine, says human clones could offer the answer to eternal life.

Theoretically, the sci-fi concept of growing bodies in labs would provide people with ‘spare’ vital organs when theirs begin to fail in order to extend their life.

Animals — most notably Dolly the sheep in 1996 — have already been cloned as part of scientific experiments to develop genetically modified livestock.

Dr Alex Zhavoronkov, head of Hong Kong-based biotech company Insilico Medicine, believes clones will become available to humans within the lifetime of young people and will provide 'spare' organs for when they become unwell Dr Alex Zhavoronkov, head of Hong Kong-based biotech company Insilico Medicine, believes clones will become available to humans within the lifetime of young people and will provide 'spare' organs for when they become unwell

Dr Alex Zhavoronkov, head of Hong Kong-based biotech company Insilico Medicine, believes clones will become available to humans within the lifetime of young people and will provide ‘spare’ organs for when they become unwell

Dolly the sheep (pictured) was the first successful animal clone, using cells taken from the udder of a six-year-old sheep, after nearly 300 attempts by researchers at The Roslin Institute, which is part of the University of Edinburgh Dolly the sheep (pictured) was the first successful animal clone, using cells taken from the udder of a six-year-old sheep, after nearly 300 attempts by researchers at The Roslin Institute, which is part of the University of Edinburgh

Dolly the sheep (pictured) was the first successful animal clone, using cells taken from the udder of a six-year-old sheep, after nearly 300 attempts by researchers at The Roslin Institute, which is part of the University of Edinburgh

And plants have undergone the same process — simply through taking a cutting — for thousands of years.

Academics hunting for immortality think the same feat is possible in humans, too.

Dr Zhavoronkov, whose Hong Kong-based firm develops drugs to treat age-related illnesses, believes the technique will become available to humans within the lifetime of today’s kids.

It will provide ‘spare’ vital organs, such as the heart, liver or lungs, for people when they inevitably become unwell.

Such body parts would be harvested from their clone and transplanted.

Blood plasma infusions doubles lifespan of rat, raising hopes for anti-ageing therapy available to humans 

A lab rat has lived to the record age of four-years-old after receiving injections of blood plasma taken from younger rodents, scientists have revealed.

Scientists hope the findings will lead to a similar treatment being rolled out to people within the next 20 years.

Rats usually live for just two to three years, on average, but Sima, the rat in the study, surpassed the previous longest lifespan by one-and-a-half months.

The study involved giving rates infusions of a purified and concentrated form of blood plasma, called E5, taken from younger animals to see whether it prolonged their lives.

Results so far suggest that those who received a placebo infusion lived 34 to 38 months, while those who received the plasma infusions lived 38 to 47 months.

Dr Harold Katcherr, chief scientific officer at Yuvan Research, which led the study, told The Guardian: ‘The real point of our experiments is not so much to extend lifespan, but to extend youthspan, to rejuvenate people, to make their golden years really potentially golden years, instead of years of pain and decrepitude.

‘But the fact is, if you manage to do that, you also manage to lengthen life and that’s not a bad side-effect.’ 

Plasma, which makes up around 55 per cent of blood, is a yellow-coloured liquid that carries platelets, red blood cells and white blood cells around the body.

Studies suggest that the treatment reinvigorates organs and tissues in animals and extend life by slowing the ageing of the liver, heart and brain. 

However, the same result is yet to be spotted in humans.

Dr Katcher said if larger animal trials show the same results, the approach could be tested in humans.

But the therapy requires the same amount or more plasma than that already in the body – meaning it could be collected at pigs in abattoirs. 

However, the idea of human clones — which Dr Zhavoronkov believes will eventually become as accessible as a car or iPhone — is hugely controversial.

This is due to the scientific difficulties, such as a high rate of death and bodily deformities among cloned animals.

There are also ethical concerns about creating a human genetically identical to another person who currently exists, or has previously. 

This could conflict with long-standing religious and societal values about human dignity and infringe on the principles of individual freedom, identity and autonomy, according to the US National Human Genome Research Institute.

Others fear the system could be abused by supporters of eugenics.

But Dr Zhavoronkov, who was born in Latvia but now works in Hong Kong, believes creating ‘many’ clones of people is the most likely method for boosting life expectancy among people.

He told MailOnline: ‘Cloning, in my opinion, is the only way to make a dramatic leap in life extension and turn longevity into an engineering problem.’

Scientists would need to develop a way of successfully cloning humans and disabling their cognitive functions so they could only be used for organs, he noted. 

Dr Zhavoronkov said: ‘If someone figures out a way to get around the ethical and regulatory problems, the technology will be available to a select few at the beginning.

‘But just like with the iPhone or cars, it should not be too expensive and you may be able to get a new body from time to time as a regular consumer.’

‘You would have spare parts for a very long time,’ Dr Zhavoronkov added, suggesting that they would be stored in specialist labs or factories.

If a person was hit by an illness, such as kidney disease, then they would receive the healthy organ from their clone, under the system.

All vital organs deteriorate with age and can be hit by illness, which can be fatal, so replacing them can, in theory, keep people alive for longer.

Dr Zhavoronkov said: ‘Transplantology has already advanced to the extent that you can transplant virtually anything.

‘If there is no rejection, since it is a perfect clone, you can have a perfect body and just focus on the longevity of your brain.’

However, organ transplants — which have been carried out since the 1950s — do carry an array of risks, including infection, blood clots and nerve damage in the short-term. 

In the longer term, the body can reject the new organ — caused by an overreaction of the immune system.

Dr Zhavoronkov is confident there will be ‘significant advances in longevity science within the next decade’.

But he noted that it would take ‘at least’ 15 to 20 years to grow an adult clone, from which organs could be harvested from.

‘So for today’s 80-year-olds, [their] chances of rejuvenation are pretty slim — their probability of dying of any cause is very high and increases with age,’ Dr Zhavoronkov said.

People who are in their eighties or older ‘have virtually no chance to live past 122’ — the current record set by Jeanne Calment, who died in 1997 after spending her whole life in Arles, southern France, he said. 

The Office for National Statistics predicts the life expectancy of men born in 2070 in the UK will reach the age of 85 on average, while women will be nearly 88 when they die The Office for National Statistics predicts the life expectancy of men born in 2070 in the UK will reach the age of 85 on average, while women will be nearly 88 when they die

The Office for National Statistics predicts the life expectancy of men born in 2070 in the UK will reach the age of 85 on average, while women will be nearly 88 when they die

Ms Calment, who smoked cigarettes and drank alcohol every day, sparked debate among scientists about what upper age limit is for humans.

However, there has since been speculation that her actual age at death was 99. 

WHO WAS JEANNE CALMENT?

Jeanne Calment, pictured with her Guinness World Record Jeanne Calment, pictured with her Guinness World Record

Jeanne Calment, pictured with her Guinness World Record

Jeanne Louise Calment holds the Guinness World Record for being the oldest person ever.

Born on February 21, 1875, she is reported to have lived to the age of 122 years and 164 days.

She passed away in a nursing home in Arles, in the south of France, on August 4, 1997.

Her unparalleled longevity has been the subject of numerous studies, both before and after her death.

She stunned doctors by continuing to smoke cigarettes and drink alcohol every day.

Jeanne enjoyed good health for the majority of her life, having even taken up fencing as a hobby at the age of 85.

Ms Calment also claimed to have met the artist Vincent van Gogh, to whom she sold painting canvasses in her father’s shop as a teenager.

‘He was ugly as sin, had a vile temper and smelled of booze,’ she said. 

Those who are in their twenties today ‘have a real chance of living many times longer than previously thought possible’ due to the possibility of a scientific breakthrough in this field, Dr Zhavoronkov said.

However, the ‘jury is still out’ on those who are middle aged due to uncertainties around the speed of breakthroughs and the rules around how they are used, he said. 

Dr Zhavoronkov also pointed to pharmacological interventions — taking drugs — as a potential way to boost lifespan.

Promising studies suggest organ transplant, diabetes and blood pressure drugs may all have anti-ageing effects.

Ongoing research, by the US National Institute of Aging, logs how drugs affect the lifespan of mice.

Results have shown that ‘reasonably safe drugs’ such as rapamycin, developed as an immunosuppressant for organ transplant patients, and type 2 diabetes drug acarbose increase longevity in mice, Dr Zhavoronkov said.

And separate analysis suggests PDE-5 inhibitors, which are used to treat people with high blood pressure, reduce the risk of age-related diseases, he said.

However, Dr Zhavoronkov believes medication will ‘only help us achieve moderate life extension’.

He said: ‘The real breakthroughs will come from regenerative medicine.

‘The ability to replace the old tissues and organs is likely to provide people with a much greater longevity runway than pharmacology.’ 

Dr Zhavoronkov added: ‘We should not really set a limit on human life expectancy.’

Reproductive cloning, which was used to duplicate animals like Dolly and would likely be the method used to clone humans, involves removing cells, such as a skin cell, from the entity that is being cloned.

The DNA from these cells are transferred into an egg cell that has had its DNA removed.

Dolly the sheep was the first successful animal clone, using cells taken from the udder of a six-year-old sheep, by researchers at The Roslin Institute, which is part of the University of Edinburgh.

But human cloning has remained elusive, despite disproven claims from some researchers that they have achieved it.