An open access review on the topic of aging and longevity, largely focused on mainstream work aimed at producing ways to gently slow aging by metabolic manipulation:

Aging drives disease. Nearly every major killer in developed countries shares a common feature: your risk of getting the disease increases dramatically as you get older. For example, the likelihood of being diagnosed with Alzheimer's disease doubles every five years after the age of 65. A similar kind of relationship can be seen for most types of cancer, heart disease, diabetes, kidney disease, and many others. What is it about getting older that simultaneously increases risk for all of these disorders? Are there common molecular changes that cause an organism to switch from youthful and healthy to aged and infirm? Can we intervene in this process to do something about it? These are some of the big questions that scientists who study the biology of aging are interested in answering.

The perspective that most age-related disorders share a common underlying biology is a departure from traditional biomedical science, one that potentially offers a more powerful approach towards improving human health. Rather than focus on curing the individual disease, interventions that target the molecular processes of aging can simultaneously delay the onset and progression of most age-related disorders. Such an intervention is predicted to have a much larger effect on life expectancy than can be attained by treating individual diseases. This is because even if one disease is cured, the relationship between age and all the other disorders of aging still holds. For example, it has been estimated that curing cancer will lead to only a 3-5 year increase in survival for an average 50 year-old woman, while slowing aging to an extent that is routine in laboratory organisms has about a 5-10-fold greater impact on life expectancy.

Importantly, these added years from slowing aging are spent largely free from chronic disease and disability, while the relatively small gains in survival by curing cancer (or any other individual disease of aging) are still associated with the inevitable age-related declines in function of every other bodily system. This concept of extending the period of life spent free from chronic disability and disease, referred to as healthspan, is a critically important idea in the field of aging-related research.

Link: http://dx.doi.org/10.12703/P5-5

Source:
http://www.fightaging.org/archives/2013/03/considering-longevity-aging-and-medical-science.php