The pursuit of extending the human life span is about enabling people to maintain a richer, healthier life for as long as possible, but just how long is it possible for a human to live for? The longest unambiguously documented human lifespan is that of Jeanne Calment. Calment died at age one hundred and twenty-two, and ascribed her longevity to generous amounts of olive oil, port wine and chocolate. While those reaching such an age must live a healthy lifestyle and be blessed with resilient genes, somewhere in this ballpark seems to be the upper limit of the human life span. However, there is research being conducted today into rejuvenating medicine that can combat the cellular causes of ageing, perhaps even allowing humans to live indefinitely.
Ageing is the multi-dimensional change in an organism’s physiology due to the damage caused by on-going metabolism, which eventually leads to pathology, characterised by gene and protein degradation, cell loss, mutations etc. Such types of damage are summarised by Aubrey de Grey, Chief Scientific Officer of the Strategies for Engineered Negligible Senescence (SENS) organisation, as the ‘Seven Types of Ageing Damage’ in his book The Mitochondrial Free Radical Theory of Ageing, where he also suggests possible treatments of these causes.
Gene deletion with periodic stem cell reseeding, a method that removes mutated DNA and introduces stem cells that replicate and provide healthy new cells to replace them, is among the suggested treatments by de Grey for many of these types of damage, as well as cell therapy (introducing of new cells into tissue) and immune stimulation (boosting of the immune system with supporting nutrients).
Caloric/dietary restriction is another method of preventing senescence. The life spans of yeast cells, fruit flies, rodents etc, have been significantly extended by altering the animal’s diet so that it is given almost no caloric intake, which results in a longer life span, but with predictably unfavourable side effects.
Enzymes such as telomerase and resveratrol (found in red wine) have also been found to increase lifespans of similarly primitive animals, and although not quite the ‘Fountain of Youth’, they offer tantalising clues as to how we might some day unravel the ageing process in its entirety and thus develop a mechanism for its prevention.
We are living in exciting times, as the prevention of ageing is currently subject to much exciting research. Although a difficult, multi-faceted endeavour, researchers remain optimistic, maintaining that many of the techniques needed for treatment are available today. The first person to live to be two hundred and twenty-two years old could very well already have been born.