The photo above is of John D. Rockefeller. The founder of the Standard Oil Company, he is considered by many historians to be the single richest human being who ever lived. Mr. Rockefeller was simultaneously a ruthless businessman and a very generous philanthropist, and is thus remembered as both a villain and a hero of American history. But for the purposes of this article, what’s relevant is that Mr. Rockefeller lived to the age of 97, and remained mentally sharp and physically active right up until almost the very end of his long life.
I’ve mentioned in a prior blog post that I’m a history buff and that I sometimes wonder whether we can learn anything from the past about better health habits. So it was that while reading a biography of Mr. Rockefeller a few years ago, I was struck by something – John D. Rockefeller was a devotee of circadian medicine, nearly a century before the field was even invented.
I’ll come back to John D. Rockefeller in a moment, but first: what is Circadian medicine?
To summarize it a bit simplistically, it’s the study of how our health is affected by the time of day, and by various inputs from the environment – particularly sunlight during the day and darkness at night, but also the timing of meals and exercise, temperature, and other factors as well.
Over the past few years, scientists have discovered something remarkable about the human body, and that is that every cell inside of us has a proverbial “internal clock” that syncs to the time of day, and that determines whether that cell is “fully online” versus in a state of rest and repair.
I am fascinated by circadian biology, because I think it offers a lot of promise to help us live healthier lives (and have seen some remarkable benefits from it, both in my own life and in those of my patients). I will have more to say about it in the future. But for now I will highlight just a few findings of interest:
One of the best ways to sleep better at night is to get a few minutes of sunlight exposure shortly after waking. Doing so “sets the clock” inside our brain that helps control wakefulness versus sleepiness. While it may seem hard to fathom, spending 15 minutes or so outside shortly after waking up can lead to a much better night of sleep 16 or so hours later.
Blood glucose responses to the same food, in the same person, can be very different depending on the time of day. For example, eating a big meal during daylight hours often has a gentler effect on blood glucose than eating the same exact meal at 9:00 pm.
Your workouts will be more effective if you do them at approximately the same time of day, because the “clocks” in your muscles will “get into the habit” of functioning most optimally at that time. Moreover, evidence suggests that human strength peaks in the late afternoon. Therefore, if you can do so, you will likely get the most benefit from your workouts if you can do them around 4:00 or 5:00 pm. (If you can’t, however, it’s still vastly preferable to workout regularly at the “wrong” time of day than to not work out at all.)
If you are interested in learning more about this topic, I highly recommend the book “The Circadian Code” by Dr. Satchin Panda, a leading researcher in the field of circadian biology. One of Dr. Panda’s key recommendations is to try as best as possible to live by a regular schedule: wake at the same time every day. Eat your meals at the same time every day. Exercise at the same time every day. Go to bed at the same time every day. There is more nuance to the topic than this, but simply getting into the habit of following a regular schedule can “train” your body’s internal clocks to function more optimally, thus leading to better health.
Which brings me back to Mr. Rockefeller. In one of those fun synchronicities of life, I read a biography of John D. Rockefeller (which I highly recommend if you have any interest in 19th century American history) not long after reading Dr. Panda’s book. In this context, one of the things that really stood out to me was how rigidly Mr. Rockefeller stuck to a regular schedule. He woke at the same time every day, ate his meals at the same time every day, took a walk at the same time every day, played golf at the same time every day, and went to bed at the same time every day. In fact, John D. Rockefeller was so devoted to his schedule that he was even known for excusing himself from dinner parties that he himself was hosting to go to bed, while leaving his guests to continue the festivities on their own.
We’ll never know for sure why John D. Rockefeller lived almost to the age of 100, in excellent health, during a time when so many died young. No doubt genetics and luck played a big role, and he had a lot of other habits that we would now consider healthy (he exercised regularly, made it a point of pride to eat small portions of food, and never touched alcohol or tobacco). But one can’t help but wonder if part of his longevity was due to the fact that his rigid devotion to a daily schedule created an optimum circadian biology.
