In the 1893 Chicago World’s Fair, Nikola Tesla lit 100,000 Westinghouse light bulbs and, like never before in history, night was turned into day. That night in Chicago, dubbed the “city of lights,” started the race to light the world and thus began the endless summer of artificial light. (3)
Electric lighting slowly filled houses, offices, towns, cities, nations and now the entire developed world is dependent on artificial light. (1)
The “Endless Summer Effect”
Before artificial light, in the winter, it would be dark in one’s home by 6pm. Today, lights don’t go off until 10 or 11pm, or even later for many people. As far as our circadian clock goes, these post-sunset, artificially-lit evenings add some 2-5 hours of extended daylight each day year-round – adding up to more than 1000 hours of artificial light each year.
In nature, as a result of millions of years of evolution, every cell in the human body is hardwired to make major light/dark cycle shifts. As the sun sets, cortisol is replaced with melatonin. The sun’s blue light at sunrise suppresses melatonin and triggers the release of the adrenal hormone, cortisol. (2)
The long days and short nights of summer are followed up with winter’s short days and long nights, and our melatonin and cortisol levels adapt accordingly. The short days of winter send an evolutionary message that it is going to get dark and cold, and food will be scarce until late spring. The long days of summer send an evolutionary message to prepare for winter by storing as much energy as possible to weather the long winter.
Summer has sent the message to feast before the famine of winter for some 3 million years. Early humans would gorge themselves on fruits, nuts, seeds, grasses and tubers each summer when they were ripe, loading up on foods rich in carbohydrates and fats to feast on in preparation for the winter famine.
The strong cravings for carbohydrates in the summer is a natural circadian response to prepare for the famine or lack of food during the darkness of winter. (1)
When we light our homes for an extra 5-6 hours after sunset, we are sending the “endless summer” message to our cellular biological clocks that it is time to crave carbs in preparation for the famine of winter.
With artificial lighting and blue light emitted from our electronics, this carb craving can last for 365 days a year.
Sugar, the most concentrated form of carbohydrates, was only available one time of year – at the end of summer, before the onset of winter. From the perspective of an ancestral diet, it would be impossible to get these sugary carbs such as fruits, potatoes, and ripe grains any other time of year. (1)
The excess carbohydrates are stored as fat in the body, as a layer of needed insulation and energy reserve for the winter. Living with hours of artificial light reinforces our natural inclination to gorge on sweets. Ever since the first taste of mother’s milk, humans were conditioned to crave sweets. In fact, we still only have one taste bud for the sweet taste, and have over 300 and counting for the taste of bitter. Bitter foods, like a dandelion, could heal you, while other bitter foods can be poisonous. As a result, we have hybridized most foods to become sweeter and sweeter.
The combination of artificial light at night and an instinctual desire for the sweet taste has been the perfect storm for chronic disease.
10 Tips to Combat the Endless Summer Effect, Sugar Addiction and Melatonin Imbalance
- Go to bed 2 hours after sunset year-round.
- Turn off computers, TV’s and cell phones before bed, or get a blue light filter for your devices.
- When you wake up, get outside and allow the morning sun’s rays to bathe your body for 5-10 minutes whenever possible. Even through a window is OK.
- Make sure there is not ambient light or LED light in your bedroom while you sleep.
- Turn off the Wi-Fi while you sleep at night.
- Stop eating foods with added sugars or sweeteners.
- Eat whole foods and avoid packaged foods.
- Try to fast for 13 hours from supper to breakfast each day.
- Eat 2-3 meals a day and avoid snacking.
- Start your day with a morning meditation – preferably with the morning sun’s rays on your skin.
Blue blocking glasses have helped my sleep. I put them on at dusk and they block all the blue light helping my body produce melatonin. I like the swannick glasses as they’re stylish however there are less expensive versions on amazon.
Go to bed 2 hours after sunset in the winter? Where I live that would be 6 pm… not very realistic!
Hi Zakiah, thanks for the comment! The idea is to do the best you can, and notice how going to bed earlier than 10pm and waking earlier makes you feel. Turning off bright lights and screens at least an hour before going to sleep. Be well.
I’ve heard that the best sleep you can obtain is from sunset to midnight.