lack of SLEEP and its connections (cancer, stress, OBESITY, poor memory)

So let's now look at sleep deprivation. Huge sectors of society are sleep-deprived, and let's look at our sleep-o-meter. So in the 1950s, good data suggests that most of us were getting around about eight hours of sleep a night. Nowadays, we sleep one and a half to two hours less every night, so we're in the six-and-a-half-hours-every-night league. For teenagers, it's worse, much worse. They need nine hours for full brain performance, and many of them, on a school night, are only getting five hours of sleep

One of the things that the brain does is indulge in micro-sleeps, this involuntary falling asleep, and you have essentially no control over it. Now, micro-sleeps can be sort of somewhat embarrassing, but they can also be deadly. It's been estimated that 31 percent of drivers will fall asleep at the wheel at least once in their life, and in the U.S., the statistics are pretty good: 100,000 accidents on the freeway have been associated with tiredness,loss of vigilance, and falling asleep. A hundred thousand a year. It's extraordinary. At another level of terror, we dip into the tragic accidents at Chernobyl and indeed the space shuttle Challenger, which was so tragically lost. And in the investigations that followed those disasters, poor judgment as a result of extended shift work and loss of vigilance and tiredness was attributed to a big chunk of those disasters.

If you are a tired brain, the brain is craving things to wake it up. So drugs, stimulants. Caffeine represents the stimulant of choice across much of the Western world. Much of the day is fueled by caffeine, and if you're a really naughty tired brain, nicotine. And of course, you're fueling the waking state with these stimulants, and then of course it gets to 11 o'clock at night, and the brain says to itself, "Ah, well actually, I need to be asleep fairly shortly. What do we do about that when I'm feeling completely wired?" Well, of course, you then resort to alcohol. 

Another connection between loss of sleep is weight gain. If you sleep around about five hours or less every night, then you have a 50 percent likelihood of being obese. What's the connection here? Well, sleep loss seems to give rise to the release of the hormone ghrelin, the hunger hormone. Ghrelin is released. It gets to the brain. The brain says, "I need carbohydrates," and what it does is seek out carbohydrates and particularly sugars. So there's a link between tiredness and the metabolic predisposition for weight gain.

Stress. Tired people are massively stressed. And one of the things of stress, of course, is loss of memory, which is what I sort of just then had a little lapse of. But stress is so much more. So if you're acutely stressed, not a great problem, but it's sustained stressassociated with sleep loss that's the problem. So sustained stress leads to suppressed immunity, and so tired people tend to have higher rates of overall infection, and there's some very good studies showing that shift workers, for example, have higher rates of cancer.Increased levels of stress throw glucose into the circulation. Glucose becomes a dominant part of the vasculature and essentially you become glucose intolerant. Therefore, diabetes 2. Stress increases cardiovascular disease as a result of raising blood pressure. So there's a whole raft of things associated with sleep loss that are more than just a mildly impaired brain, which is where I think most people think that sleep loss resides.