When we think about the human population of the earth in future and issues regarding population growth, its easy to jump right to birth rates. However, one also must consider the fact that mortality rates are changing as we learn more about treating and preventing disease. And, because of this, we are living longer.
According to the Centers for Disease Control, as of 2011, life expectancy in the United States was an average of 78.7 years. It is estimated that life expectancy has nearly tripled for humans since their earliest days; much of that advance has occurred just since the industrial era. Although a great deal of this improvement has been due to improved sanitation and the ability to avoid and treat infection, a shift has been occurring and more recent increases in life expectancy are now attributed to extension of life, a decline in death rates in older populations from heart disease, cancer and other illnesses associated with aging. (Barazzetti)
It appears to be commonly accepted that average lifespans will continue to increase, to an extent, as we are better able to treat disease, but should we investigate ways to deliberately increase the lifespan? Certainly, most peoples’ first concern is likely to be what the quality of an extended life would be. In health care today we put a premium on quality of life, not just quantity. For the purposes of this piece, I will assume, as Dr. de Grey does, that increasing longevity is associated with prolonged quality life and delays morbidity and will not result in a “global nursing home”.
One of the common concerns when discussing extending lifespan is the idea that extending life is unnatural in some way. Some people see it as against their religious beliefs; the argue that to extend life would be to spiritually “miss the essence of life”(Pijnenburg) or that it is “playing God” (Partridge 2009). Some may feel that it would be like tampering with evolution or nature although it can be argued that deliberately prolonging life expectancy through health care and technology is no different that what we have done for centuries through public health and medical care. (Partridge 2007)
David Gems argues in his proposal that to “decelerate ageing” (reducing the incidence of and delaying the onset of age related diseases), because of its ability to reduce suffering on such a large scale, is a positive thing. De Grey also makes a strong case that “curing ageing” is really the same as saving a life; he compares treating a young person’s leukemia to delaying aging:
In each circumstance we are giving the beneficiary a greater remaining healthy potential lifespan than they would have if we held back, which is the beginning and end of what we mean when we say we have saved their lives, and also of what we mean when we say we have extended their lives. (de Grey, 662)
He goes so far as to say that not investigating and advancing longer life spans can actually be seen as ageism and a violation of human rights. “Human rights do not get any more fundamental than the right to go on living.”
Another issue arises around the justice of extending lifespan. Obviously, this would be something that is (at least at first) to those in First World countries and would likely increase disparities between the “haves” and the “have nots”. (Pijnenburg) Partridge and Hall quote Tom Mackey as asking how we can justify advancing the “selfish desires of relatively affluent people to live to 150 when millions of poor people die before 50.” They go on to counter that research into extending lifespan does not preclude concurrent efforts to prevent premature death. “Moreover,” they contend, “we do not demand a guarantee of equal access to new technologies before they are developed. If we did, no technological progress could be made.” (Partridge 2007) And this is certainly true. How many advances in medicine and health care were immediately available to all populations? The arguments about disparity certainly deserve consideration as certainly an already wide gap between socioeconomic classes will likely increase, but I do not feel they alone are enough to stop investigation.
There are also more practical reasons for opposing extending lifespan including the societal and economic impact of having a population that lives to be 120, 150 or more. How will work be distributed? How will health care be rendered? How will wealth distribution change? How will we balance population growth? Do we have the resources to support the additional population? Certainly, these very practical issues need to be considered as we go forward. Even without research and investigation into specific therapies to increase lifespan, there will be some increase just as a consequence of better treatment of disease as we have already seen. We need to evaluate all of these issues as our world’s population continues to grow, with or without dramatic increases in longevity.
I agree with David Gems response to concerns about what some see as a “post-human” future:
Yet, in the end, the shape of the future is so uncertain and subject to future discoveries within the field, and the potential benefits so great, that none of these arguments seem to come close even close to being reasons for stopping research that may lead to deceleration of human ageing. (p 111)
Certainly, we must give all of these areas (and many more) due consideration as people live longer.
CDC FastStats. Deaths: Final Data for 2011. http://www.cdc.gov/nchs/fastats/life-expectancy.htm
Partridge, B., Lucke, J., Bartlett, H., & Hall, W. (2009). Ethical, social, and personal implications of extended human lifespan identified by members of the public. Rejuvenation Research, 12(5), 351-357. doi:10.1089/rej.2009.0907 http://dx.doi.org.library.esc.edu/10.1089/rej.2009.0907