Friday, October 10, 2008

Discarding Our “Aging-Blinders”

This is a long, but important, post...

This term at Queen’s I am teaching my favourite undergraduate course entitled “Genetics and Justice”. This course examines the ethical, social and legal implications of the genetic revolution. And yesterday the class had a spirited debate and discussion on the aspiration to retard (and even eliminate) senescence.

To set the context for the class, we first watched this video which presents the cutting edge research on longevity science. And we then read “Pursuing the Longevity Dividend” and debated the proposal to invest $3 billion a year in aging research. In the last part of the class two students gave seminar presentations on arguments for radical life extension. The first was on Nick Bostrom’s paper “The Fable of the Dragon Tyrant”, the second on Aubrey De Grey’s “Life extension, Human Rights, and the Rational Refinement of Repugnance”.

Those who have read some of my academic work, or past entries on this blog, will know I am an advocate of longevity science. I am very interested in hearing the arguments and reactions people have to the aspiration to slow human aging, for I myself shared some of these reservations when I first began thinking about these issues. But over time I realized that many of my initial reactions or concerns to longevity science were either misinformed or focused on concerns that are, in the big picture of things, minor when compared to the enormous benefits of extending healthy life.

So here I want to reflect a bit on some of the issues that arose in our class discussion and debate concerning tackling human aging. For this exercise actually aids me in my own research and deliberations, as I attempt to get a clearer sense of the arguments for and against retarding human aging.

I began by asking my students, who are all in their final year, how many of them have taken a university course that addressed some of the health or social implications of human aging. Only one student had taken a course that briefly addressed an issue pertaining to aging. It was a course on the welfare state and examined social provisions like pensions. But besides that, no one had taken a course that engaged with the kinds of issues that we were about to discuss.

My own education as a student was very similar to that of my current students. None of the courses I had taken in my 9 years of University addressed the issue of aging. Of course if one had taken a degree in gerontology, rather than philosophy or political science, things would be very different. But it is surprising that aging does not figure more prominently in programs that have a heavy policy focus (like political science) or deal with profound questions concerning ethics and justice (like philosophy).

So the current neglect of the empirical realities of humans, and human societies, is, in my opinion, one of the greatest shortcomings of the current state of higher education. And a central goal of my career aspirations is to help remedy this intellectual deficit. But it is a difficult aspiration. Disciplines, and researchers, work within established paradigms and there are lots of incentives for “going with the flow” and large disincentives for going against the grain.

Take contemporary philosophical discussions of distributive justice, for example. There are lots of incentives for working within the current established paradigm- you are more likely to get your work published in the established journals, make connections with other like-minded researchers, be invited to give talks, etc, etc. And if one is early in one’s career- either trying to land that first job or get tenure- these things matter a great deal. And I believe this explains part of the reason why scholars interested in distributive justice almost completely ignore the realities that we are temporal beings and that this has significant implications for the basic structure of society. The risks of forging new ground, especially early in one’s career, often outweigh the proposed (career) benefits. And so there is a strong bias for working within the status quo. And if the status is impoverished, as I believe it is, this is a problem.

For those in mid-career and beyond, other kinds of considerations can impede a scholar’s ability (or rather willingness) to go against the grain. It is much easier to continue building on one’s earlier work rather than start over again building a new foundation. And a major shift that involves learning extensive empirical knowledge, or crossing traditional disciplinary boundaries, requires a curious intellect and commitment, and that fire might not burn in the belly of many post-tenure scholars.

Thus a discipline like political philosophy (and ethics) can continue on for decades without anyone realizing that we are wearing “aging-blinders”. And now that there is a scientifically credible basis for believing that we may be able to alter the rate at which molecular and cellular damage occurs to our bodies and minds, we must discard these “aging-blinders”.

Having said all the above, it is important to note the really incredible advances that are being made in the study of the biology of aging and Universities are starting to take this seriously (though I think it is fair to say scholars in the humanities and social sciences have not caught up with these advances, hence the large vacuum I mentioned above). Many universities and non-profit organizations are spear-heading serious study and engagement with human aging. Below I link to a random sample of some links to give you a taste of some of the interesting work being done (click the links below for a “snapshot” of these):

1 2 3 4 5 6 7 8 9 1011 12 13 14 15 ...

Scholars in the humanities and social sciences should take human aging seriously as it raises many profound questions in need of serious scholarly attention. What contribution could a philosopher, for example, aspire to make? Let me give it a shot....

OK, so let’s get down to some details about how we might set the stage for the claim that human aging is actually a very important ethical and social issue that should receive far greater attention than it currently does. It is important to recognise that there are many, many challenges facing humanity this century. And we constantly hear our elected officials championing the importance of different national and global goals. From the war on terror and climate change, to infectious disease, conflict and poverty- we face many problems and it is not easy to determine what our biggest priorities ought to be.

When thinking about priorities one could invoke many different dimensions of wellbeing. For example, addressing the current economic crisis is a priority because it has an impact on people’s retirement savings, their ability to pay their mortgages, their employment, etc. So financial wellbeing can certainly be one dimension we invoke to help us get a handle on priorities.

But there is an even more fundamental dimension of wellbeing than financial wellbeing- and that is being (and staying) alive in the first place. Of course a financial crisis that leads to unemployment is a problem. But a financial crisis that leads to unemployment and starvation and death, well that is a much BIGGER problem. And so human deaths, while not the only measure of the magnitude of the severity of a problem, ought to play a prominent role in our deliberations about priority setting.

OK, so what causes most human deaths? We must be careful how we answer this question. If we ask it historically (i.e. what killed most humans in the past?- say a 100 years ago, or 10 000 years ago, etc.) then the answer will be very different than if we ask it as a forward-looking question (i.e. what will most likely kill the world’s 6.4+ billion population?). Furthermore, it is sometimes tricky to identify just one thing as the cause of death. Sometimes many factors play a role (e.g. diet, inactivity, etc.). Putting aside these points, let’s look at the things that killed humans in the year 2005.

According to the World Health Organization, approximately 58 million people died in the year 2005. And if we examine what was (primarily) responsible for these deaths, we can get a better sense of what our biggest priorities ought to be.

Some estimates suggest that around 150 000 people died from climate change in that year. Road crashes killed 1.2 million (and injured or disabled another 50 million). HIV killed 2 million, and cancer 7.6 million.

So let’s stop here. When presented with this kind of data we begin to see how big certain problems are in relation to other ones. Cancer, for example, is a leading killer. And so is poverty. And these factors are often interconnected. Most of the 7.6 cancers deaths in 2005 were in low and middle income countries. Furthermore, the death toll does not settle the priority issue- we must also consider what it would cost to tackle the issue in question as well as the likelihood that our action would bring about the desired result. But the death toll does add some vital insight to the determination of what the magnitude of any particular problem is. And so comparing the numbers in this way is useful in helping us grasp a sense of the “big picture”.

Now, where does aging figure in the story of human death? Pinning down the numbers is a source of contention. But some estimate that aging is responsible for 2/3rds of all human deaths, worldwide. That would mean that somewhere in the neighbourhood of 38 million deaths in 2005 were age-associated. Given the staggering numbers involved here, you would think that we are trying everything we can to lower the prevalence of age-related death. Sadly, we are not. Why is this the case? (see this)

Two things are important to bear in mind here. Firstly, these death trends are new and unprecedented in human history. Historically, most human beings that lived on this planet died well before the diseases and afflictions of senescence would be visited upon them. Thomas Hobbes was right- life was “nasty, brutish and short”. However things look very different for the 21st century. Now unprecedented numbers of human beings, 2 billion by 2050, are expected to live beyond 60 and they will fall prey to the diseases of aging. Our risk of disease, frailty and death *doubles* every 7 years during our adult life. And we must take urgent action to try to alleviate the disease and suffering that will come with the world’s expanding, aged population.

OK, so those are the kinds of considerations that have won me over to the “aging is a big problem” camp (and I hope they will motivate you to think about these issues as well). Aging is a global problem. It is also clearly a domestic problem for the developed countries. Most of your family and loved ones will suffer one of the diseases of aging- cancer, heart disease, stroke, etc. And so if you care about the fate of these loved ones then you should care about longevity science.

Now if, as I contend, aging is such a big problem, we need to ask- can we really do anything about it? And unless one has been closely following advances in aging research, one could be forgiven for thinking the answer is no. But that is false. There is a sound scientific basis for thinking that we can intervene in the biological process of aging, thus extending the number of years people can expect to remain healthy. And one of the major obstacles to our achieving this is the current neglect (and hostile attitude) many people have to the aspiration to modify the rate of aging. Permit me to now challenge some of the most popular objections people have.

Consider what I will call “Key Value Premise”: Suffering disease and death is bad. If you agree with Key Value Premise, then you must also come to grips with the reality of aging. Let’s call this “Key Empirical Premise”: aging increases our risk of morbidity and mortality; not just by a small amount- these risks increase *exponentially* with age (until around age 95, when late-life mortality plateaus).

So if suffering disease and death is bad, and aging dramatically increases these risks, then we ought to be seriously considering ways of tackling aging. When things are clearly laid out like this, it is hard to see how anyone could object to making longevity science more of a priority (who can deny the value and/or empirical premises noted above?)

Well, there are some important challenges that I think are worth taking seriously. And these reactions are ones students in my classes have raised over the years. The first objection is the claim that it is wrong to prioritize the effort to extend the lifespan when there is so much poverty in the world. A second objection is that any anti-aging intervention will no doubt be unequally accessible to the rich and poor in the world. So these technologies would simply exacerbate existing inequalities.

Let’s call the first objection the “Messed Up Priorities Objection”, and the second objection the “Inequality Objection”. And for the time being I will only address these in the context of a discussion of global (rather than domestic) justice.

These kinds of objections are the most interesting and compelling (even if, ultimately, flawed) objections to longevity science. Why is the “Messed Up Priorities” objection flawed? There are a few problems with this line of reasoning. Firstly, if one accepts Key Value Premise (that suffering disease and death is bad) then one must accept the reality that something bad will be visited upon the 2 billion plus senior citizens who will populate the world by 2050. And given the sheer number of people involved here, it seems odd to say that worrying about their disease and death is a “messed up” priority. Most of these people are people that are currently alive in the developing world. So the goal of tackling the diseases of aging is something that aspires to help (in the future) those currently alive in poor countries!

Contrary to what most people in the richest countries believe, people in other, less rich countries, are in fact living longer and will suffer the same afflictions that currently kill our own population. Recall this earlier post where I pointed out that the top 3 causes of death in the United States is identical to the leading causes of death in China. The number of human beings that suffer from chronic disease is twice the number of deaths due to infectious diseases (including HIV/AIDS, tuberculosis and malaria), maternal and perinatal conditions, and nutritional deficiencies combined! And that fact should illustrate why the “Messed Up Priorities Objection” to tackling aging is flawed.

Now there is a further detail worth addressing here. One might accept Key Value Premise, but retort that it is even worse to suffer disease and death early in life than it is to suffer these things later in life. So getting cancer at age 10 and dying is worse than getting it at age 80 and dying. I agree. But that does not change the fact that it is still bad to suffer disease and death at age 80. And when one considers how many people will suffer age-related morbidity and mortality, we are hard pressed to deny that tackling aging ought to be a top priority. I address the issue of priorities and aggregation in greater detail in this recent paper.

Now let’s turn to the “Inequality Objection”. So this objection states that we should not invest public funding in longevity science because any benefits likely to come from this science will not be equally enjoyed by all. There are many things to say here. Firstly, if we are really committed to tackling aging then we can make *equal access* to these interventions a priority. Secondly, even if one thinks it is impossible to ensure equal access to these technologies, the fact that not everyone in the world would have equal access to a novel intervention should not keep us from pursuing it. Would we object to pursuing a cancer therapy simply because it would not be immediately available to everyone in the world? No.

Thirdly, over time most medical interventions come down in price, thus resulting in more people enjoying them. And so we must ask- is it better to completely forfeit a beneficial technology if it will not be immediately accessible to everyone in the world rather than permit it to be unequally accessible for some period of time? To answer this question let’s consider the most important (though often neglected) public health technology of the past two centuries- the sanitation revolution.

All three of the countries that I have lived in have had safe, piped water connected to homes, and sewers rinsed with water. These measures have dramatically lowered the risk of disease and death in the countries I have lived in. Tragically, 40% of the world’s population still do not have access to basic sanitation. This is a gross injustice. But what is unjust is not that there is an inequality in access, but that the poor lack access to basic sanitation. So the goal would be to ensure everyone has access to basic sanitation, not to deny those countries that can afford basic sanitation these technologies. The same is true of anti-aging interventions. We should not try to prevent anyone from having access to these technologies simply because they might not be equally accessible to all. Rather, we should support policies that would ensure the largest number of people possible have access to them. And so the “Inequality Objection” is premised on a confused moral sensibility that leads to disastrous policy prescriptions.

Finally, to those who say all this talk of life extension and slowing aging is nonsense, I wish to leave you with one final statistic to mull over. Consider the incredible increase in life expectancy that the United States has enjoyed over the 20th century. In the year 1900, 18% of males born in the US died before their first birthday. By the end of the century, the cumulative mortality rate in the US doesn’t hit 18% until age 62! Through our hard work and innovation amazing improvements in our health prospects have taken place. Who knows what amazing things await humanity this century. Contrary to the pessimists who think the earth will be destroyed by climate change or terrorists, I actually think my children and grandchildren could inherit a wonderful and exciting future. And I am committed to fighting for the realization of that optimistic future! And so we must discard our "aging-blinders".