The movie âÄúIn Time,âÄù in theaters now, imagines a future where age has been cured. Characters live to be hundreds of years old, yet retain all the vitality of their youth.
This is not just a fantasy. The prospect of curing age is something we ought to take seriously, in the same way weâÄôre serious about curing cancer or any other disease. Indeed, curing age ought to be our societyâÄôs single greatest priority.
ItâÄôs important to differentiate the two different concepts we refer to when we use the word âÄúage.âÄù
 The first refers to how long a person has been alive. The second meaning is biological age, which is accompanied by symptoms such as wrinkles, graying hair and the deterioration of oneâÄôs physical and mental capacities. It is this latter sense of age, otherwise known as senescence, (from the same Latin root as âÄúsenilityâÄù) that is a disease.
Senescence is essentially the accumulation of damage to a personâÄôs body over time. The damage begins in the womb before youâÄôre even born. Your body has self-defense mechanisms that repair this damage, but at some point during middle age, the damage accumulates faster than your body can repair it. If we can improve the bodyâÄôs self-repair mechanisms, we can slow down and perhaps even reverse senescent damage.
In principle, we know that senescence can be cured. In the same sense in which we know that we could cure cancer if we could just prevent cells from growing out of control, we could prevent senescence if we could prevent cell damage from accumulating in our bodies.
We also have a great deal of empirical evidence to demonstrate that age is curable. Researchers have conducted a multitude of studies that demonstrate that when animals such as mice and fruit flies are placed on restricted-calorie diets, they live far longer than normal. When placed on near-starvation diets, the lifespan of mice more than doubles. Lower calorie consumption is also the primary factor that explains why women have longer average life-spans than men, (even after one takes into account the increased probability that men will die in war or crime-related violence or accidents). Essentially, the less food one consumes, the less oneâÄôs body metabolizes, which reduces the amount of damage that accumulates in the body.
This is not to suggest that we should promote anorexia. First, while calorie-restriction reduces senescence, one needs to ensure adequate nutrition in oneâÄôs diet; the consequences of malnutrition are usually worse for oneâÄôs health than senescence. Second, a longer lifespan is probably not worthwhile if those extra years are filled with miserable hunger pains.
However, the fact that we understand a great deal about how senescence works, and that we have empirical evidence that the process can be slowed down, give cause for optimism that we could find an alternative mechanism to mimic the benefits of calorie restriction.
Furthermore, even if scientists are not able to make any major breakthroughs, the anti-senescence research already available offers a great deal of practical advice on an individual basis. Competitive eating contests, for instance, are inadvisable for oneâÄôs health. One should also think carefully before engaging in high-intensity exercise activities such as marathons. Contrary to what one might expect, regular marathoners do not have longer life expectancies than normal. The reason is that in order sustain that level of exercise, marathoners eat far more than average, often double or triple the normal caloric intake. The lesson is that there is a sweet spot for an ideal level of exercise: Moderate exercise is extremely healthy for an individual, but at a certain point the benefits are nullified by the increased food consumption required.
The most common objection to curing age is that it will create an enormous overpopulation problem. While thatâÄôs certainly true, reducing population growth is not an acceptable reason to refrain from curing a disease.
To illustrate the point, consider how you would react if someone told you they opposed a cure for cancer because it would exacerbate the population crisis. The only difference between curing cancer and curing senescence is that the latter would save far more lives.
âÄúIn TimeâÄù imagines a dystopian solution to the overpopulation problem, where people are simply killed off when they are no longer considered productive to society. After a person turns 25, they have one year left to live, after which they must buy âÄútimeâÄù with either labor or commerce. If they run out of time, they die. The poor frequently die young, while the rich are functionally immortal.
While âÄúIn TimeâÄù captures the zeitgeist of widespread opposition to inequitable distribution of wealth, it fails to give a realistic account of how society would most likely react to senescence cure. Rather than increasing the death rate by killing people off, the far more likely and far more desirable reaction to overpopulation would be to reduce the birth rate by regulating reproduction. Nations would need to decide how large a population they could sustain, and limit reproduction accordingly.
Governments and universities should shift a greater proportion of their medical research toward curing age. While research on ailments such as heart disease, AlzheimerâÄôs disease, and cancer are all worthwhile objectives, the money we spend on them is like hacking at branches when we could be solving the problem at the trunk, because young people seldom suffer from those ailments. If we can figure out how to cure senescence, we will cure those other diseases in the process. Ultimately, senescence is responsible for two-thirds of deaths worldwide, making it the most lethal disease in the world. We need to shake off our complacency and recognize age as a curable disease.