What Happens To Your Body And Brain If You Don't Get Sleep | The Human Body

[Music] My name is Matthew Walker I am a professor of neuroscience and psychology at the University of California Berkeley and I am the author of the book why we sleep we certainly know that a lack of sleep will actually prevent your brain from being able to initially make new memories so it's almost as though without sleep the memory inbox of the brain shuts down and you can't commit new experiences to memory so those new incoming informational emails are just bounced and you end up feeling as though you're a music you can't essentially make and create

those new memories we also know that a lack of sleep will lead to an increased development of a toxic protein in the brain that is called beta amyloid and that is associated with Alzheimer's disease because it is during deep sleep at night when a sewage system within the brain actually kicks into high gear and it starts to wash away this toxic protein beta amyloid so if you're not getting enough sleep each and every night more of that Alzheimer's related protein will build up the more protein that builds up the greater your risk of going on

to develop dementia in later life what are the effects of sleep deprivation on the body well there are many different effects firstly we know that sleep deprivation affects the reproductive system we know that men who are sleeping just five to six hours a night have a level of testosterone which is that of someone 10 years their senior so a lack of sleep will age you by almost a decade in terms of that aspect of virility and wellness we also know that a lack of sleep impacts your immune system so after just one night of 4

to 5 hours of sleep there is a 70% reduction in critical anti cancer fighting immune cells called natural killer cells and that's the reason that we know that short sleep duration predicts your risk for developing numerous forms of cancer and that list currently includes cancer of the bowel cancer of the prostate as well as cancer of the breast in fact the link between a lack of sleep and cancer is now so strong that recently the World Health Organization decided to classify any form of nighttime shift work as a probable carcinogen so in other words jobs

that may induce cancer because of a disruption of your sleep wake rhythms we also know that a lack of sleep impacts your cardiovascular system because it is during deep sleep at night that you receive this most wonderful form of effectively blood pressure medication your heart rate drops your blood pressure goes down if you're not getting sufficient sleep you're not getting that reboot of the cardiovascular system so your blood pressure rises you have if you're getting six hours of sleep or less a 200% increased risk of having a fatal heart attack or a stroke in your

lifetime there is a global experiment that is performed on 1.6 billion people twice a year and it's called daylight savings time and we know that in the spring when we lose one hour of sleep we see a subsequent 24% increase in heart attacks the following day another question perhaps is what is the recycle rate of a human being how long can we actually last without sleep before we start to see declines in your brain function or even impairments within your body and the answer seems to be about 16 hours of wakefulness once you get past

16 hours of being awake that's when we start to see mental deterioration and physiological deterioration in the body we know that after you've been awake for 19 or 20 hours your mental capacity is so impaired that you would be as deficient to someone who is legally drunk behind the wheel of a car so if you were to ask me what is the recycle rate of a human being it does seem to be about 16 and we need about eight hours of sleep to repair the damage of wakefulness wakefulness essentially is low-level brain damaged