Monday, October 20, 2008

Why Worry About Aging?

Humans are vulnerable to seemingly endless intrinsic and extrinsic risks. Consider for a moment the multitude of environmental risks we face each day. These range from being in a traffic accident and consuming contaminated food we purchased at the grocery store or a restaurant to being assaulted or falling down a stairway.

Taking some risks is unavoidable. Locking oneself inside their home all day will not insulate one from risks of harm. For such behaviours have their own risks- like malnourishment, muscle atrophy and jeopardizing one’s mental health! Furthermore, no one lives on an isolated island like Robinson Crusoe. So even one’s home is only as safe as one’s neighbourhood... country... planet.

Given the diverse and pervasive nature of the risks facing any given population, we need to think clearly and rationally about managing these risks. As individuals, we must consider the consequences of our lifestyle- like our diet and physical activity. These actions can have a dramatic impact (for better or worse) on our health prospects. And governments must prioritize the various policies they could pursue to protect and improve the health prospects of the population.

Given the magnitude of the stakes involved in these kinds of deliberations about risk, it should be apparent that such deliberations are among one of the most important things individuals and societies could do. For if we invest all our energies into tackling the smallest and most trivial of risks, we then leave ourselves vulnerable to the most probable and costly of harms. Tragically, we do not do a good job of thinking rationally about risk (see this great book, for example).

Examples of the errors we commonly make about thinking sensibly and consistently about risks are all too common. For example, think of the case of an overweight smoker who decides to stop consuming anything with aspartame because they are worried about its possible adverse effects on their health. Or a mother who smokes while pregnant and then worries about having her child immunized for fear that it will cause her child to develop autism.

And governments do not always fare much better. Recall this post and the obsession the Bush Administration has paid to reducing the likelihood that any American will die from terrorism. And yet this Administration has done little to prevent the 300,000 deaths a year associated with obesity and excess weight, or the 400,000 deaths a year associated with cigarette smoking. And while global action to tackle climate change often dominates the news, there is little attention paid to things that could actually aid the globally disadvantaged now (and for little cost), like providing bed nets for malaria and removing farming subsidizes.

There is a vast array of empirical research that examines how individuals and groups reason poorly about tackling risks. These range from problems of limited knowledge and biases to group polarization. I am now spending a good deal of my time reading this literature and doing so has proved very useful in bringing together diverse threads of my academic research. Here I will mention just one- the importance of aging research.

When people ask me what I am working on I inevitably mention aging and the aspiration to retard human aging. This provokes many different responses. The most common response is a sense of surprise that we might actually be able to do something about aging. This is of course understandable, for if one had not been following the field of biogerontology for the past few years one might assume that aging is immutable, for that was a common belief. But this belief has been proven wrong- aging is not immutable.

Once I note this people often persist in their scepticism, and express doubt that we could actually develop a technology that could slow aging in humans (rather than just in mice). Again, this scepticism is understandable, indeed some scepticism is warranted. But I often ask them how much scepticism they have about finding a cure for cancer, or reversing climate change. And when it comes to these issues they are pretty optimistic about the likelihood that these goals could be achieved.

So I push them a bit further... and it becomes evident that this optimism is not based on any scientific experiments that demonstrate a particular therapy could cure all 200+ types of cancer, or that climate experiments demonstrated that we could reverse the rise in global temperature. What their optimism is based upon is the desire to achieve these things, that they would create enormous benefits for humanity. Again, I understand the appeal of this line of thinking. We want to believe that we can achieve those things that would really do a lot of good in the world.

Well, when it comes to aging the good news is there is an even sounder scientific basis for thinking we could actually retard human aging AND the magnitude of these benefits (say slowing aging by just 7 years) would be even bigger than a cure for cancer or reversing climate change. And so these points provide all the more reason for getting behind longevity science!

And so this takes me to the title of this post- “Why Worry About Aging?” Well, let me give you a few reasons. Firstly, we should worry about aging because aging is one of the biggest risks factors for death and disease in the world. Odds are, most people you know who have died in your lifetime were older than you are. This is not just a coincidence! Aging increases the risks of morbidity and mortality. After age 28, your risk of death increases almost exponentially. Biodemographers estimate that every 7 years during your adult life your risk of frailty, disability and death doubles. That is a very sobering insight!

So given the magnitude of the harms of aging, coupled with the fact that scientists have made incredible advances in understanding the biology of aging (like which genes can increase the lifespan of a species), you would expect everyone to be worried about aging. Is this so? My own sense is that this story is mixed and complex.

As individuals, few adults are overjoyed with the fact that they have aged yet one more year every time they celebrate a birthday. In fact, I think it is only children who really *celebrate* a birthday. Most adults grumble and complain about getting older. They would prefer not to be reminded of how old they are with a cake filled with a wide stack of candles.

And so at some level everyone knows, to some degree, that aging is a big problem for them as individuals. No one enjoys the fact that their risk of cancer, heart disease, stroke, AD, etc. will continue to rise for all of their remaining years. When in certain moods, we can all admit this. But we don’t want to go on and on about it every day. It’s depressing! And so we tend to bury these feelings deep inside and go on with our daily activities wearing “aging-blinders”.

And so we find there is an enormous disconnect between what the public actually demands of their governments- like protection from terrorists, tackling abortion , etc.- and what would actually substantively improve their lives. If you really want government to reduce your chances of death and disease, then get behind aging research. If there was no chance that scientists could actually develop a drug or intervention that could modify the rate at which the molecular and cellular damage of aging occurs then it would be cruel to tell people to “worry about aging”. But given where the science actually is, it is irrational and irresponsible *not* to tell them to worry about aging. Especially when people fear so many things that really do not pose a great threat to their health and well being.

And this highlights another challenge for longevity scientists- trying to motivate people to get behind aging research by telling them they have good reason to worry about aging, and yet at the same time not depressing people so much that their mental health is jeopardized! So I don’t subscribe to instilling “fear of aging”. Fear is usually the enemy of sound, responsible policy-making. But I admit that walking the “worry about aging” line is a challenging and fine line to tread.

People are often very disturbed when I start telling them about the realities of aging; like how it increases our risks for disease and death. They wonder how I sleep a night. They fail to see that my concern with aging is not primarily driven by a concern about my own health prospects (though of course I do care about that), but rather about the impact aging will have on the future of humanity. Senescence will cause more disease and death this century than anything else. What does trouble me most at night is that fact that we invest very little in the science that could actually substantively improve the life prospects of those living in both poor and rich countries.

And so I think more public discussion of why would should worry about aging can be a good thing. The way I look at it is like this- we all worry about something. And it is best to worry about those things that (a) are really a big (rather than small) problem and (b) are problems we could actually do something about. Once you realize there is a scientific basis for believing that aging satisfies (b), then you will want to get people more worried about aging and supporting aging research.