Has the elixir of youth come of age?

Consumers in the West devote a large amount of time and money to holding back ageing. File photo / Greg Bowker

It is one of the oldest jokes in the gerontologists' book - if you want to live to a grand age, choose your parents carefully. Jeanne Calment, who had the longest confirmed human life span in history, attributed her longevity - she died in 1998 aged 122 years, five months and 14 days - to a diet rich in olive oil, regular glasses of port and her ability to "keep smiling". But destiny undoubtedly played the most important part.

We spend millions of pounds each year on anti-ageing tonics, potions, vitamins and creams, trying to stave off the ravages of the years. But our genetic inheritance trumps all other factors in determining how well we age and how long we live.

By unravelling the genetic determinants of longevity, scientists believe they will be able to manipulate them to add not only years to life, but also life to years. An elixir of youth remains a distant dream but medicines to help us live longer and better are moving closer.

At a conference this week, Turning Back the Clock, organised by the Royal Society, researchers described the progress that has been made in the science of ageing.

At least 10 gene mutations have been identified that extend the lifespan of mice by up to half, and in humans several genetic variants have been linked with longevity. They include a family of genes dubbed the sirtuins, which one Italian study found occurred more commonly in centenarian men than in the general population. A subsidiary of drug giant GlaxoSmithKline is now looking at sirtuins, and their association with a range of age-related diseases including type 2 diabetes and cancers.

Other gene variants affect the production of growth hormone and insulin-like growth factor (IGF), both of which increase metabolism - organisms with higher metabolism tend to die sooner.

A possible of way of slowing ageing would be to slow metabolism by blocking receptors for growth hormone and IGF. A small Massachusetts biotech company, Proteostasis, is investigating this pathway involving IGF as a potential target for anti-ageing drugs.

Another key drug target is an enzyme called cholesteryl ester transfer protein (CETP), which affects levels of "good" cholesterol, that help protect against heart disease. Drugs that inhibit the enzyme are being developed by two other major pharmaceutical companies, Merck and Roche.

Also promising, but still far from yielding concrete results, are telomeres, which are present in every cell. Telomeres shorten with every cell division, like a burning fuse; when they can shorten no more, the cell dies.

Inhibiting the enzyme telomerase to prevent the shortening of the telomeres in effect extends the lifespan of the cell, and, as we are comprised of millions of cells, could extend life.

Developments such as these herald a new era of longevity research and drugs based on them will "probably be available for testing from 2012", Professor Nir Barzilai of the Albert Einstein College of Medicine in New York told the conference.

He said: "I'm seeing 100-year-olds who are not only 100 years old but in great shape. They're driving and painting, and they say life is beautiful. I have this bias that makes me believe we have the ability as a species to get to 100 if we prevent some of these age-related diseases."

Centenarians tended to have genes that delayed the onset of conditions such as Alzheimer's and heart disease.

"When they eventually die they die of the same things that people die of in their seventies and eighties. It's just that they do so 30 years later," Professor Barzilai said.

"The cost of treating 100-year-olds in their last two years of life is a third of what it costs to treat somebody aged 70 to 80. People who die between 70 and 80 are sick in the last few years of their life. Centenarians are dying healthy, all of a sudden."

His "vision" was of a once-daily pill that would stave off the effects of old age and would probably be taken when a person reached their forties or fifties.

But to achieve it, ageing would need to be classed as a treatable condition in order to stimulate the research funds needed to develop it. Drugs regulators in the US and Europe would only licence medicines for specific illnesses, not for something as general as ageing.

"[Ageing] is something that is very important in the background. It needs to be defined as a disease," he said.

Consumers in the West need little persuading - we devote a large amount of time and money to holding back ageing. It is an irresistible target for "snake oil salesmen". Hundreds of compounds that are claimed to boost memory and learning ability are available over the internet. Cosmetic surgery is booming and anti-ageing-products are the fastest-growing area of the UK's £673m skincare market, according to analysts Mintel.

Three years ago, an anti-ageing skin cream called Protect and Perfect by No7 caused near riots as shoppers scrambled to get their hands on it after a BBC Horizon programme revealed laboratory tests showed it worked better than more expensive creams. Boots sold almost six million tubes in the nine months following the programme, proving the marketing power of hard science.

In 2009 a study published in the British Journal of Dermatology confirmed its superiority and it became the first anti-ageing cream scientifically proven to eliminate wrinkles.

Ageing cannot be reversed but it could, perhaps, be delayed. The emergence of the extremely old population has only happened in the past 50 years and is chiefly due to improvements in the health, lifestyle and environment of the elderly that started in the 1950s - how we eat and drink, where we live, what we do.

Life expectancy soared by more than 30 years in richer nations during the 20th century and shows no sign of slowing. It has risen steadily, by three months every year, for the past 160 years, and there is no reason to think it has hit a limit.

In the early part of the last century, improvements in infant and child survival contributed most to growing life expectancy, but since the 1950s, the biggest gains have been in the over-eighties, who now have more than twice the chance of surviving to be 90. We are living better for longer, and spending fewer of our extra years disabled and dependent on others.

What worries most people about ageing is losing their faculties and the ability to perform the daily tasks of living - eating, dressing, bathing and getting around.

But despite increases in cancer and chronic conditions such as diabetes and arthritis, disability has been falling. This apparent paradox is explained by earlier diagnosis and improved treatments which have rendered these conditions less disabling.

In the future, more of us will fall ill, but the illnesses will affect us less. The result is that we may live to see our great-grandchildren and even our great-great-grandchildren.

Within a couple of generations living to be 100 could be as routine as collecting a bus pass is today. Some scientists go further and believe the first person to live to 150 may already have been born.

Increased longevity is one of the modern world's great successes, but long life without health is an empty prize.

As Jeanne Calment indicated on her 122nd birthday: those who live moderately live long.

- INDEPENDENT