Predicting the time of your death

A new study published in the Annals of Neurology identifies a common gene variant that could also predict the time of day you will die.

Yes, and the time is 11 am in the morning and it is likely to be on your birthday and the day after you get your paycheck!

For more on this, read Lindsay Abrams' great overview of the study and its findings. What's fascinating about it from a tech perspective, though, is the role that technology -- or, more specifically, the absence of it -- plays in making the biggest biological determination there is: the time of our deaths. 

Circadian rhythms are physiological in origin, but they have structural analogs -- analogs that have to do with the highly mediated way we human animals live our lives. When we're younger, we impose schedules on ourselves. We use machines to wake us from sleep. We use artificial illumination to escape a mandatory night.

But the circumstantial realities of old age change that, to a significant extent. "Social jet lag" -- the phenomenon through which our natural circadian rhythms are undermined by rigidly collective social schedules -- is less of a factor for people who aren't (generally) working and whose daily routines aren't (generally) governed by strict itineraries. It is less of a factor, in other words, for people who are relatively unreliant on technology. Retirees can sleep when they need to, wake when they want to, and generally obey the whims of their bodies much more readily than younger people can.

And that change in the way older people live also affects the way they die. Because, just as circadian rhythms regulate things like preferred sleep periods and the time of peak cognitive performance, they also regulate the times during which we're most likely to experience an acute medical event like a stroke or heart attack.

There is a "biological clock ticking in each of us"and the technological freedom that comes with people's retirement can actually end up bringing a kind of cruel regularity to their deaths. Since circadian rhythms control wakefulness -- alertness, blood pressure, heart efficiency -- it stands to reason that the flip side could be true, as well: that the rhythms that stimulate human activity could also stimulate its end.

But, then ... where does the 11 a.m. frequency -- and, for the GG group, a less-common 6 p.m. frequency -- fit into that framework? Why would we be more likely to die during those hours than at other times of the day?

Genetics. Well, genetics and statistics.  For example, there is an increase in cardiac death from about 3 or 4am to about noon. This is thought to coinicide with the increase in hormones, like cortisol and adrenaline, that increase heart rate and blood pressure, and may push someone with cardiac problems over the edge, causing cardiac death. 

That's not to say, of course, that 11 a.m. is also the most common time for getting hit by a bus, or bitten by a snake, or consumed by a ball of Mayan prophecy-fire. But for the population of people who have made it to old age -- the people who will die of natural causes rather than circumstantial ones -- there's a probabilistic element to the time that they will die. And that's because death by "natural" cause is natural in the fullest sense. Once we take leave of our technologies, our biologies take over. 

It is clear that the genetic messages that empower our lives will also, eventually, orchestrate our deaths.