In her controversial book, Lights Out, T.S Wiley argues that light is a physiological trigger that controls dopamine and hormones like cortisol. Wiley argues that by extending our waking hours beyond the natural day with artificial lighting, very few people get enough rest at the hormonal level to achieve and maintain optimal health. In her view, chronic sleep deprivation leads to fatigue and an unnatural appetite, which in turn lead to weight gain, exhaustion and disease.
Writing in view of evolutionary theory, Wiley argues that chronic late-nights send our bodies the message that we are constantly in a pre-hibernation phase (summer) of carbohydrate storage, which leads to an insulin resistance that never amounts to actual hibernation. Instead, we stay in the state of fat accumulation, insulin resistance, and subclinical hypertension ALL YEAR ROUND. This tends toward obesity and all the conditions associated with it. It is noteworthy that all of the symptoms associated with cardiovascular disease – – high blood pressure, blood vessel constriction, increased clotting factors, high cholesterol, and lax calcium channels, all mirror the symptoms that would actually serve us during prehibernation. The problem is that they are chronic and there is no rest.
Melatonin is a master-switch hormonal controller and when we go to sleep at sunset, our whole body is soaked in a melatonin bath. When this switch is out of sync due to chronic fatigue, it responds by aging the body prematurely, interpreting this disturbance as an indication that you are no longer viable.
Melatonin levels enhance leptin and leptin is what keeps your brain in the ‘fed’ stage so you stay asleep and produce more melatonin. But when you sleep less at night, the lower melatonin levels result in lower leptin levels, which make you hungrier, both day and night.
Aside from the melatonin bath it provides us, going to sleep with the sun results in a sharp increase in prolactin, the most major effect of which is to enhance the production of T cells and NK (natural killer cells), both of which are the first lines of cancer defense.
Longer sleep and lower carbohydrate intake go hand in hand. More sleep allows us to regulate the hormones that control our cravings and conversion of carbohydrates. Lower carbohydrate intake, in turn, decreases the raw materials that our body (in a perpetual state of pre-hibernation) uses to convert into fat to store for the famine that never comes. Lower carbohydrate intake and longer sleep our ways that we can help prevent the health-risks associated with the advent of agriculture and electricity.
Serotonin is the neurotransmitter responsible for controlling our impulses. Its levels are highest when there is a lot of insulin, which the body interprets as a sign that there is an abundance of carbohydrates: it’s summer! Serotonin levels increase during this perceived state of nature to prevent your impulsiveness from screwing up your chances at mating and fighting, in short, surviving. It reduces impulsive behaviour by reducing your ability to make connections: sensory input is filtered and memory retrieval is blunted. When our serotonin levels are high, we literally become stiffer and rigid in our behaviour, which is often expressed as repetitive, obsessive-compulsive, or paralytic.
The only good news to Wiley’s account is that when we do rest, all of these symptoms are reversible. With adequate sleep, melatonin levels increase and our cravings for carbohydrates are quelled, helping us break the vicious cycle.