The circadian rhythms of death

This is possibly one of the weirdest things I have read this year.

You (yes, you) are more likely to die around 11:00 am than any other time. That is, provided your death is the sort that happens in old age, as opposed to, say, being hit by a bus.

That's because of circadian rhythms — the biological processes that, among other things, regulate when we get tired and when we wake up. For most of our lives, we consistently manipulate these cycles — setting alarms, enforcing bedtimes, getting just tipsy enough that we don't notice it's 1:00 in the morning. But for the elderly and the very sick, those socially mandated sub-routines no longer apply. Over time, your body starts slipping into patterns that are governed internally, rather than externally.

And, it turns out, the majority of humans have an internal cycle that makes them more likely to die at 11:00 am. At The Atlantic, Megan Garber explains:

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. As study co-author Clifford Saper -- who is also the James Jackson Putnam Professor of Neurology and Neuroscience at Harvard Medical School, and also the chairman of the Beth Israel Deaconess Medical Center Department of Neurology -- explained to me over email: There is a "biological clock ticking in each of us."

In an interview with the lead author on the paper this information comes from, Garber gets into a much-more-detailed explanation — including the genetic variants that seem to control this timing. While the majority of us are most likely to die at 11, a minority is most likely to die around 6:00 pm.


  1. If someone knows which group they’re in, AA, AG or GG, would it be a good idea for them to take it easy at certain times of the day, or would it not matter?

    I’d heard of the “Sundowners’ Club,” people who hang onto life until the sun sets. They might be part of the GG group mentioned in the article. It’s interesting that the group that’s represented by 16% of the population gets a nickname.

    1. In medicine, ‘sundowner’ usually refers to someone who becomes (obviously) confused or demented at the end of the day.

  2. Makes perfect sense in that the 11 am folks die for the diurnal carnivores and the 6 pm folks die for the nocturnal carnivores, right?

  3. I work near a hospital, and I may pick a particular time of day to take a break and have a nice, relaxing stroll over by the emergency department, from now on. (911 on speed dial.) 

  4. Thanks Maggie. I’m 64, eat few vegetables, take little exercise, have an unenviable family medical history and it’s 5 minutes to 11 o’clock.

    Pray for me!

  5. All caring individuals should immediately contact there legislators and demand that 11am be removed from the official clock.

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