Did you know that we evolved from ancestors who slept in shifts?
Our ancestors retired at sunset and slept for a few hours, only to wake up again for a couple of hours to stoke the fire, feed the livestock, or do other caretaking. They then ultimately retired for another 4 hours or so of sleep before waking again at dawn. Our 8 hour night of solid sleep is a newer pattern that is a byproduct of industrialization.
Humans have always had a range of sleep clocks, and this has been an important benefit for the perpetuation of the species – we needed someone to be awake to defend and alert if there was a threat. Today the average midpoint of sleep is 4 am, indicating we are a society made of more night owls than morning larks.
Here are some other interesting facts around sleep – in true/false format – see how many get right, we’ll explore more next time as well 🙂
Sleep and mental health are inextricably linked.
The correlation between poor quality sleep and mental health is staggering:
People are 10x more likely to suffer from depression and 17x more likely to suffer from anxiety with poor quality sleep.
SSRIs (antidepressants) are approved for insomnia.
While widely used to assist sleep, not only are SSRIs not licensed for this use, SSRIs also inhibit REM sleep by 84%. (!!!)
Daylight Savings time is a really bad idea.
Daylight savings is a bad idea with poor health consequences. There is an increased association with depression when we ‘fall back,’ and an increased association with heart attacks when we ‘spring forward.’
It’s beneficial to catch up on sleep on the weekends.
The discrepancy in sleep patterns between the weekday and the weekend can have a similar effect to switching time zones. It’s been called ‘social jet lag’ for this reason. Getting into the pattern of going to bed later and getting up later on the weekends can cause us to feel tired and fatigued when we return to working hours, and it can take 3 weekdays to get back on track.
The more you filter blue light on your screens, the better!
You only want to filter about 30% of blue light during the day, after sunset, it’s safe to filter 100% of blue light. Blue light as a part of the UV spectrum is very important for signaling the suprachiasmatic nucleus of the hypothalamus – our circadian rhythm regulator. So too much filtering could negatively impact sleep.
Poorer sleep is connected to climate change.
A 2002-2011 survey done on 765,000 individuals (who simultaneously tracked night time temperature) linked poor sleep with climate change. Quality sleep is connected with a lowering of body temperature, and nighttime temperatures are hotter now. Global temperature elevation has the most negative impact on sleep in the summer
Does all this make you want to optimize your sleep? Check out my first post for sleep suggestions and consider the following if you aren’t doing this already:
- Connect with the natural world regularly, regular and frequent exposure to natural light is the most powerful support of our circadian rhythm.
- Dim your lights to mimic the light outside.
- Take technology breaks on the weekends.
- Consider a 20-minute mindfulness meditation practice to unwind from the day.
- Make a list for tomorrow so you leave your worries on the shelf for the night.
- Sleep in a cool, dark room.
- Consider ambient, white noise.
Source: Dr. Krista Anderson-Ross’ lecture on sleep @Mid Atlantic Regional Conference 9.2020