Hmm, had no idea long sleep is also linked to developing more diseases. Also makes one wonder in what way the causal effect (if any?) works, i.e. do those people tend to sleep more because of the diseases or is it the other way around?
That’s a fallacy, because most people are in the 7 to 9 hour range, thus the overall probability is lower. The other ranges are usually people with non-nominal lifestyles, which can also very likely impact disease probability.
You can’t just turn around a graph like a mathematical equation... unless it’s sensationalism.
The sound of the study is retrospective (looking back) instead of controlled; so they probably didn't do anything to account for if someone was already healthy or sick before enforcing a sleep duration.
I've experienced this myself and have witnessed it in coworkers and in my father, all of us having worked the different shifts at one point or another. For me, whenever I was on 2nd or 3rd shift my health, state of mind, and life in general suffered. I also never felt rested or clear-headed no matter how much or how little sleep I got.
Should you live near a school with an 8am marching band out in practice, or maybe you live in or near an apartment complex with a yard service peaceably armed with a lawnmower and leaf blower at 9am, then good luck to you. Setting up the equivalent of a photographic dark room gets me only so far.
Nowadays I avoid shift work as much as possible. The money isn't worth it for me.
There was a short BBC documentary series about sleep a few years ago, and one of the episodes focused on a man who slept for ten hours a day and still felt drowsy and without energy. After going through a sleep clinic with all kinds of tests, the conclusion was that he should try to sleep only six hours.
The basic issue was that because he spent ten hours a day in bed, trying to catch up on what he thought was a lack of sleeping causing his tiredness, his body never got tired enough to enter deep sleep. Because he missed his deep sleep cycles, his sleep did not recover his energy properly. So this was a vicious cycle.
After a few weeks of forcing himself to wake up after six hours of sleep his problems were basically solved.
So the thing to remember is that duration of sleep tells you nothing about the quality of sleep.
EDIT: While we're here, I've had a lot of sleeping problems in the past, so here some other tips that I remember from this series, and from my sister who studied chronobiology (the science of internal clocks in biological systems, including sleep cycles):
- Note emphasized enough by this article: the deep sleep cycle is necessary for cleaning your brain from neurodegenerating toxins[0]. Getting that stage three deep sleep is essential for your mental health!
- Don't use alcohol to induce sleepiness: yes, it makes you fall asleep faster, but it also prevents you from the deep sleep. You end up not being refreshed afterwards.
- Train your brain to associate your bed with sleeping. If you can't sleep, leave the bed, do something that's not so stimulating that it keeps you awake like reading a book (avoid that mobile phone at all cost) until you feel sleepy enough to go back. This article singles out teenagers here, which is ridiculous: adults are just as guilty of doing this to themselves.
- Because of the previous point, make sure you don't use your laptop/phone in bed, nor have a TV in the bedroom.
- The reason warm baths can help with falling sleep: a fast drop from a high core temperature to a low temperature triggers drowsiness. So what the bath does is heath you up until you are warm. If you then leave that bath and enter a cold bed that needs to be warmed up this triggers a sleep response. Hot milk probably gives a similar trigger, but I'm sure about that one.
- Fasting can help with jet lag. Specifically: don't eat for at least sixteen hours (drinking water is fine), then eat your first meal at breakfast (tangent: "break fast"). This resets the body clock.
[0] https://www.nih.gov/news-events/news-releases/brain-may-flus...
I can usually fall asleep fine, but will often wake up early and can't get back to sleep. If it's anytime after 5am, I just get up and start my day.
The fact that there are multiple kinds of exhaustion, and that we might not distinguish them, can in itself be part of the problem, since you can end up trying to fix the wrong thing.
Although exercising is never a bad idea anyway.