Like it or not, life expectancy is going to increase. We are poised to witness a biomedical revolution in which aging is seen as a disease, and not a necessary natural process.
The latest research in this quest for a fountain of youth has demonstrated that it is possible to reverse aging in mice by feeding them a chemical called 4-OHT, thus ramping up the activity of a naturally-occuring enzyme called telomerase, whose function is to repair the broken DNA sequences called telomeres that cap the ends of chromosomes. Every time a cell divides, those telomeres get shorter, so in a sense, the number of times that a cell can divide is limited, but telomerase can lengthen the shortened telomeres, and prolong the cell's life.
In the study, the organs of the mice damaged by aging were regenerated to a youthful state, including the brain.
The only caveat that needs to overcome: telomerase seems encourage the growth of tumors. For some it's a deal breaker, but for others, such as Ronald DePinho (a cancer geneticist) and David Sinclair (a molecular biologist), telomerase would actually prevent cancer in the first place by protecting DNA from damage.
Granted, repairing broken telomeres would not be a perfect cure for aging, as short telomeres is not the only cause, but combined with other therapies, it would become part of a wonderful medical arsenal against this deadly condition.
Now, I know, I can hear some of you yelling 'But what about overpopulation?". Well, that's an entirely separate question,
The fact that this game-changing research could potentially make overpopulation worse, should not be used as an excuse not to pursue a cure for aging. Besides, with aging cured, the need to procreate and ensure the continuation of the species is not as dramatic. Overpopulation is easy to fix. Aging is not. But aging is the more important problem to fix in the short term. We can't ignore the real, immediate problems we have today because we don't want to deal with future hypothetical problems.