As a biological anthropologist (in a previous life) I understand that evolution has no directional goal, it simply states that there is a natural selection for those gene variations that yield a better chance of survival and subsequent reproduction (in that particular environment). We can look at many mammalian and human features and rationalize them with this lens. For example, we are standing on two feet which may have an advantage to see predators in tall grasses, or that we have eyes in the front of our head giving us stereoscopic vision for swinging better in trees.

Those variations gave a survival advantage and were then able to live to spread their genes.

Sleep is a puzzling evolutionary trait, what advantage is there to spending 30% of our lives in an unconscious, paralyzed state which makes us vulnerable to predators, not reproducing, protecting our offspring or getting nutrients? One theory is that mammalian life started out in this sleeping state and over time evolved to live in a waking state, as sleep is the price we paid in order to be in this waking state. Thinking about sleep being our proto-state helps in understanding its function a bit better, at least from an evolutionary point of view. Regardless, sleep is incredibly important in resetting our brain and body’s health. It helps to regulate hormones, our immune system, physical recovery, learning, solidify the creation of new memories, clean out the toxin buildup that accumulates throughout the day in the brain neurons, and emotional regulation just to name a few. There is a lot we do not know about the effects of sleep on the body but we see evidence that lack of sleep can affect every tissue in the body.

Sleep as a process is a very complex orchestration of brain cellular activity. The process progresses through a predictable cyclical pattern of stages of sleep. Each stage provides some contribution to the ‘resetting’ of the system.

Because sleep affects every tissue in the body the converse seems to be somewhat true as well, that every tissue in the body may disrupt sleep… or so it may seem. For many of us sleep becomes more elusive as we age and thus will throw us in a catch-22 for chronic disease development. Sleep deprivation will drive up our stress hormones, most notably cortisol, which is one of our ‘fight or flight’ hormones. Cortisol will work to increase our serum glucose levels by mobilizing glycogen stores and peripheral fat bringing it to our liver for conversion into glucose. When the pancreas senses the elevation of glucose in the blood it increases the insulin production to push the glucose into the muscle cells. If the muscle cells are full and cannot store any more glucose (insulin resistant) then the insulin will tell the liver to put the glucose back into storage form in the form of visceral fat (fat that is stored around organs like our liver, pancreas, heart, and kidneys) which increases all-cause mortality. And that is just one reason that I see sleep as a pillar for preventing chronic disease as well as ‘step one’ for treating already developed chronic disease.

Contact us to explore how your sleep stacks up and how it might be improved to optimize your healthspan.