During an interview on the BBC's Hardtalk show, anti-ageing researcher Aubrey de Grey was challenged by a journalist, who put it to him that in spite of the hype the experts cannot slow the ageing process by a single day – certainly not with any magic pill. And yet most science writers agree that such interventions will soon be possible. But if so, when? And what will the consequences be?
In his recent book Homo Deus, Oxford professor Yuval Harari states bluntly that the great scientific quest of the 21st century will be to "cheat death." And yet the idea of slowing, or even halting, the ageing process remains controversial. Critics argue that it is not only impossible but immoral. The world is already overcrowded, and in parts of it, most notably Africa, the birth rate continues to rise.
Others point out that the moral argument is irrelevant since it is practically impossible. For example, Joanna Masel, a professor of Ecology and Evolutionary Biology, has said "ageing is mathematically inevitable... There's logically, theoretically, mathematically no way out."
The problem, say the critics, is that we are in a catch-22 situation. As you age, most of your cells wind down, while others grow out of control. Clear out the dysfunctional, sluggish cells and cancer cells will proliferate; do something about the cancer cells, however, and the sluggish cells will accumulate. Either way it means problems.
Those who wish to slow the process, on the other hand, argue that acceptance is the major obstacle they face. People have convinced themselves that ageing is natural and that trying to stop it is blasphemous. They have done so, argue the researchers, because the best way to reconcile yourself to something dreadful is to pretend you welcome it.
Researchers also roll their eyes at any talk of "ageing gracefully." For most people, ageing is an ugly, wretched experience, filled with pain, indignity and loss. Your looks fade, your libido drops, and your body creaks and aches. And such pain is not only physical. For many, ageing also means depression, fear, and loneliness.
First, a distinction needs to be made between one's biological and chronological age. Imagine a New Year's Eve party in 1999, where you meet two twins, born in 1939. Their chronological age is exactly the same – 60. But one of them has been a lifelong alcoholic and binge-eater who never exercised. The other is a fitness instructor who jogs every day and eats carefully. Though they have the same chronological age, biologically the first is older than the second. In other words, his body has aged faster because he has taken so little care of it.
Ageing is the consequence of changes that occur to the body over time. And these occur throughout life. They also tend to be for the worse. Even teenagers, for example, lose their childhood ability to hear sounds above 20kHz. And women in their mid-20s are already undergoing a decline in fertility. The middle-aged start to lose energy and muscle mass, and around half of all men have lost their hair by their 50s.
We accept ageing because we see it everywhere, not just in ourselves and those we love but in our pets and even the flowers in our garden. And yet not everything does age. A species of jellyfish known as Turritopsis, for example, doesn't. In fact, it can reverse the ageing process! Even some species of turtle do not age, since their organs don't gradually break down.
So ageing means deterioration over time. But why do we deteriorate? Human beings are composed of cells. Just as the atom is the basic building block of matter, the cell is the basic building block of life. And ageing takes place at the level of the cell. As the years pass, substances known as age pigments build in the cells, interfering with their metabolism, which gradually wears out, causing a breakdown in organ function.
Clearly, some people age more quickly than others. Stress certainly plays its part, as does obesity, smoking, poor diet, lack of sleep and lack of exercise. And yet at present there is little we can do. Even if you were to retreat to the woods, live a stress-free life, eat nothing but raw vegetables and fish and practise yoga and meditation every day, you would still age.
So how close are we to radically slowing the process? The answer, of course, is that no one knows. All we can say is that serious work is being done. Until very recently, the idea of slowing the ageing process was dismissed as the dream of cranks and charlatans. Today, billions are being invested in the project.
Even the most skeptical admit that some kind of progress is inevitable. For example, in 2013, Calico, an independent research and development company, was founded by Google Inc. to find ways of combatting ageing. Peter Thiel, the PayPal founder, has also invested a small fortune in the project.
Perhaps most significant of all, ageing research now attracts investors who are not themselves scientists. For example, Jim Mellon and Al Chalabi have just published Juvenescence, an overview of what life science companies are actually doing. Mellon made millions by recognising investment opportunities; such men do not invest in something unless they are sure of a return.
What makes such research even more exciting is that the money is not being spent on just one technology, which will either succeed or fail. Some are working on stem cell therapies, others on gene therapies; some put their faith and time into nanotechnology or senescent cell clearance, others into tissue engineering and advanced robotics. Artificial intelligence will also play its part. While it is quite possible that one or two of these will disappoint, it is hard to believe that all of them will.
Given all this, many believe we will be able to control ageing by the mid-2030s. That does not mean immortality. And it doesn't mean a "cure for ageing." Neither does it mean that people will no longer die. It simply means that for the first time we will be able to repair accumulated damage and slow the process down.
This will mean an ever-greater disparity between biological and chronological age. Indeed, some imagine a future in which 150-year-olds look no different to those in middle-age, where people will be shocked to discover that their handsome date is in fact a 95-year-old.
The first and most obvious worry is overpopulation. The world's population has dramatically increased over the last couple of centuries, and it is still rising. Some parts of the world, such as Germany, do have relatively low birth rates, but others, especially Africa, still have very high ones.
The social effects also need considering. For example, imagine it is the 2030s. Thanks to medical advances, average life expectancy is around 120 in the developed world, and people in their 70s have the energy and appearance of fit 40-somethings. What will this mean for career advancement? Traditionally, the managers and leaders of industry, academia, etc., stepped aside in their 60s and 70s to make way for a new generation. What if they decide to remain in post for another 30 years?
And what about the impact on families and relationships? Could a marriage really last 100 years? In his book The World in 2030, Ray Hammond imagines 70-year-olds who look like 30-year-olds. That would mean greater temptation. If people remain sexually attractive into their 90s, could they also remain loyal to one partner for such a long time?
Still, this is all hypothetical. Right now, medical science can do little to slow the ageing process. Even the healthiest inhabitant of the richest country is fortunate to live beyond 90. And if he or she does, they will almost certainly have several chronic health problems. In any case, many find the whole idea repellent, flatly stating that they don't want to live to 150, that even if it were possible they'd find it unbearably dull.
However, many do welcome these advances and would like to live a lot longer. And, though your doctor may not be able to rid you of wrinkles and gray hair, there are things you can do. Laura Deming, for example, a leading researcher into ageing, told the U.K.'s Sunday Telegraph newspaper "sugar is the worst thing you can eat in terms of ageing." And that includes refined carbs, especially things like cookies, cakes and white bread.
Inflammation also speeds ageing. Again, you can reduce this by cutting out sugar and refined carbs. The supplement turmeric also has anti-inflammatory properties, so take a capsule a day and use it on your food. Oily fish, like tuna, salmon and sardines, combat inflammation as well. If you dislike eating it, take a fish oil capsule each day.
Exercise is also important, but avoid rough contact sports like boxing, rugby, American football, etc, all of which lead to inflammation. Instead, try swimming, pilates, yoga and hiking. And push yourself, not just physically but mentally. For example, if you love literature, reading Milton or Tolstoy demands little effort. Though Paradise Lost or War and Peace may be tough, you will be using the same parts of the brain you have always used. Instead, take a course in physics or pottery.
Rudi Westendorp, a Dutch professor and author of Growing Older Without Feeling Old, stresses the need to eat a "colorful" diet. Obviously, you should eat lots of fresh fruit and vegetables and reduce the amount of junk food and alcohol. But eating the same things every day is not enough. You need to eat a wide variety of fruits and vegetables, of many different colors.
Finally, there is calorie restriction. The more you eat, the quicker you age. Not only do people eat badly, they simply eat too much. As Harari observes, for the first time in human history more people are dying from eating too much than from eating too little. Westendorp goes further, arguing that "the advice to stick at the right weight is far more important than the specifics of what you eat."
Whether we ever "conquer ageing," as some people put it, is impossible to predict. It is also impossible to predict when the first interventions will be available. All we can say for sure is that such technologies are coming – and we'd better be prepared.