Sleep

Sleeping well is one of the foundations of health, and today almost no one sleeps well. And as with everything, the pills they sell to “sleep” actually make things worse. This chapter is based on the work of A Midwestern Doctor.

Why sleep is everything

Sleep is not a blackout. It is an active process, organized in cycles, and each phase does different work. During deep sleep the brain cleans itself, removing its waste through the glymphatic system — the same drainage discussed in Chapter 7. During dream sleep (REM) it organizes memory, fixes what was learned during the day, and processes emotions. Because REM predominates in the second half of the night, going to bed late or getting up early does not cut sleep evenly: it cuts REM most of all.

Sleep is also the clock that sets every other rhythm in the body. Light is the master signal: the brain reads when there is light and when there is darkness in order to decide when to release melatonin, when to raise cortisol, and when to raise or lower body temperature. Morning light shifts that clock earlier and anchors it to the solar day; evening light shifts it later and pulls it out of sync. This is why when you get your light matters as much as how much of it you get.

It is not only how many hours: it is when, and the same time every day

This is the point most often missed. A 2024 study of nearly 61,000 people, using more than ten million hours of accelerometer data, compared regular sleepers with irregular ones. The most regular had 20–48% lower risk of death from any cause, 16–39% lower cancer mortality, and 22–57% lower cardiometabolic mortality. And most striking of all: regularity predicted mortality better than duration did.

In October 2025 the American Heart Association issued a formal scientific statement in the same direction: circadian disruption has substantial effects on cardiometabolic health, the regularity of sleep timing matters as much as its duration, and people with robust circadian rhythms had 62% less cardiovascular disease than those with fragmented rhythms. This is no longer an alternative-medicine opinion.

There is a name for the gap between your weekday schedule and your weekend one: social jet lag. It works as though you flew across time zones every week. A 2026 analysis of more than 51,000 people found that those with two or more hours of it had 30% higher cardiovascular risk — and the effect held even in people getting a normal number of hours.

The price of sleeping badly

The heart. When the clock moves forward for daylight saving and people must wake an hour earlier, a Michigan study observed a 24% increase in heart attacks the following Monday, and a 21% decrease when the clock falls back in autumn; a 2024 meta-analysis across ten countries confirmed the spring increase, though smaller and variable between studies. A Japanese study of 2,282 workers found that those sleeping less than six hours had four to five times more coronary events than those sleeping seven to eight. A study of 474,684 people found 48% more risk of developing or dying from heart disease with short sleep — and note that it also found more risk with excessive sleep. And one figure that will sting: a Harvard study of 23,000 Greeks found that after they gave up the siesta, over six years they had 37% more risk of dying from heart disease, rising to 60% among working men.

Immunity and cancer. In 2010 the World Health Organization classified shift work — one of the surest ways to wreck the sleep cycle — as a probable human carcinogen. An English study of 10,036 people over 50 found 33–62% more cancer risk with poor sleep. In healthy young men, sleeping four hours instead of eight cut natural killer cells, which eliminate cancerous cells, by 72%. And in a 2002 study, young men who slept four hours a night for six nights produced less than half the antibodies after a flu shot compared with those who slept seven to eight — and that loss persisted even after normal sleep was restored. Among 56,953 nurses, sleeping five hours or less was associated with 1.7 times more pneumonia over four years.

Blood sugar and weight. Too little sleep increases appetite, the pull toward sugary food, and the hunger hormones; it raises blood glucose and lowers insulin sensitivity. In a study of 23,620 Europeans, sleeping less than six hours was associated with 6–41% more diabetes. A meta-analysis found insufficient sleep made children 89% more likely to be obese and adults 59% more likely.

A word about these figures: where a range appears, it is because the range exists in the research. The high figure is usually the first one, and the low figure is what remains after adjusting for other factors. They are given here in full, deliberately. Be wary of anyone who quotes you only the top end.

The mind. Sleep loss brings brain fog and takes memory, and with age that stops being an annoyance and becomes a risk. In 737 adults followed for six years, badly fragmented sleep was associated with 22% more risk of Alzheimer's, and up to 50% in the worst cases. Among 346 older people with normal cognition, those with insomnia proved 139% more likely to develop Alzheimer's. Among those who already have the disease, the most common sleep disorders appear in half of cases or more. And a 2020 study using repeated scans found that disrupted sleep accelerated the accumulation of Alzheimer's plaque and forecast the onset of dementia. In other words: poor sleep does not merely accompany the disease, it runs ahead of it. See Chapter 20.

At the wheel. Driving drowsy is as dangerous as driving drunk. The sleep-deprived brain enters microsleeps: for fractions of a second the person is simply not there. For comparison, at 0.08 blood alcohol the risk of crashing is four times higher, and at 0.15 it is at least twelve times higher. Sleep loss is of the same order.

Teenagers are not lazy

At puberty the biological clock genuinely shifts later: an adolescent falls asleep later and needs to wake later. Forcing them into school before dawn leaves them chronically sleep-deprived, and it is measurable. When a Kentucky county delayed the school start by an hour, accidents involving teenage drivers fell 16.5%, while rising 7.8% in the rest of the state. A Minnesota district that moved from 7:30 to 8:00 saw accidents fall between 6% and 70% depending on the district. One in Wyoming that moved from 7:35 to 8:55 saw them fall 70%. And a 2024 prospective study found that delaying the start by an hour was associated, seven months later, with more sleep, fewer insomnia symptoms, and improvements in depression, anxiety, stress and life satisfaction.

And contrary to what is usually assumed, waking early does not by itself prove a person needs less sleep. What matters is whether they wake refreshed after a real opportunity to sleep, or wake prematurely — tired, irritable, unable to fall back asleep. In children, sleep fragmented by an unrecognized breathing problem often shows up not as daytime sleepiness but as inattention, hyperactivity, or falling school performance.

How much is needed, by age

An adult needs between seven and nine hours, and there are those who argue seven is already too few. Children need far more, because sleep builds the brain: between 4 and 12 months, 12 to 16 hours; between 1 and 2 years, 11 to 14; between 3 and 5, 10 to 13; between 6 and 12, 9 to 12; and between 13 and 18, 8 to 10.

Sleeping pills are a trap

Almost all sleeping pills are sedatives, not sleep aids. The difference is not a technicality: they leave you unconscious while blocking precisely the sleep that repairs. The result is a person sedated all night and exhausted all day, accumulating every harm of not having slept. It is the same mechanism as alcohol, and as the medications in Chapter 21.

The figures are hard. One study found that people using sleeping pills were twice as likely to die, and three times as likely if they used them daily. Another, comparing 10,529 users with 23,676 controls over two and a half years, found 3.6 to 5.4 times the mortality depending on the number of pills; and among those taking at least eighteen a year, 7–99% more risk of dying from cancer. The authors calculated that in a single year those pills were associated with between 320,000 and 507,000 excess deaths in the United States alone. They also increase infections: one large study found 54% more pneumonia and 32% more deaths from pneumonia.

The over-the-counter ones are no better: almost all are antihistamines, and they too are sedatives that ruin the sleep cycle.

Most revealing of all: the first-line treatment that sleep-medicine guidelines themselves recommend for chronic insomnia is not a pill at all. It is cognitive behavioural therapy for insomnia. It exists, it works, and it is almost never prescribed.

Common medications that take your sleep

If you sleep badly and take medication regularly, it is worth reviewing the list with your doctor before adding anything. Among those that disrupt sleep are decongestants, asthma inhalers, common blood-pressure and diabetes medications, antidepressants, opioids, prostate medications, stimulants and corticosteroids.

The GHB case: there was a remedy, and it was buried

This story has the same shape as the DMSO story in Chapter 14 and the one in Chapter 20, which is why it is worth telling.

Gamma-hydroxybutyrate was first synthesized in 1874, and from 1964 it was used in Europe as an intravenous anaesthetic. It turned out to have a remarkable property: it put a person directly into deep sleep, and they woke genuinely rested. For those who had lost the ability to sleep properly — through chronic insomnia, fibromyalgia, or earlier injury — it was not another sedative; it was getting the function back. According to Dr. Ward Dean's review, it also showed effects on growth hormone, on alcohol and opioid addiction, and on anxiety.

When it reached the United States in 1990 and began to be sold as a supplement, the FDA moved. Fifty-seven calls to poison control were publicized, nine of them involving intensive care and none fatal. In parallel, the fear of Rohypnol as a date-rape drug was transferred onto GHB, and the press repeated the word without checking anything. In 2000 Congress placed it in Schedule I, the category for substances with no accepted medical use — more restrictive than cocaine. The same law made an exception for a pharmaceutical preparation of the same compound, which was placed in Schedule III.

The data that existed did not support the campaign. GHB accounted for less than 0.1% of the substances mentioned in emergency department reports. When English police examined 120 sexual assault cases in 2006, 119 involved alcohol and only two GHB. A 2010 review detected it in between 0.2% and 4.4% of reported assaults. And Rohypnol, which genuinely was used for that purpose, stayed in Schedule IV alongside Valium.

Today the pharmaceutical preparation — sodium oxybate — costs between $60,000 and $100,000 a year, almost no doctor can prescribe it, and one must meet the criteria for severe narcolepsy to qualify. In 2010 the FDA voted unanimously against approving it for fibromyalgia, despite several favourable trials, citing its potential for abuse.

Note: this is told as history, not as advice. GHB is a controlled substance and possessing it is a crime in most countries. This book does not explain how to obtain it or in what quantity to use it, and you should not go looking for it: outside medical supervision, and mixed with alcohol or sedatives, it is genuinely dangerous. What matters here is the other lesson, the usual one: when something cheap and effective threatens a large market, it is not debated — it is buried.

How to sleep well naturally

Before the specifics, it helps to understand what is being pushed. There are three levers. One is sleep pressure: through the day the brain accumulates adenosine, and that accumulation is what produces sleepiness; caffeine works by covering that receptor, not by removing the tiredness. The second is the circadian rhythm, the clock that responds above all to light. And the third is that sleeping is an active process that costs energy, so if there are obstacles the body may simply fail to manage it. Almost everything below moves one of those three.

Look after your internal clock. Go to bed and get up at the same time every day, weekends included; regularity, as we saw, weighs more than the total hours. In the morning, get out into natural light as early as you can: that is the signal that anchors the clock to the day.

Look after the light at night. Avoid the blue light of screens and bulbs: use filters like f.lux on the computer, the equivalent setting on your phone, or glasses that block it. At home, prefer warm light in the evening. And sleep in a completely dark room: curtains that really block, and nothing that blinks.

Cool the body. The best temperature for sleeping is around 18 °C (65 °F). A warm bath before bed helps, because on getting out the warm blood rises to the skin and the water, evaporating, cools it.

Caffeine and alcohol. Both ruin sleep by different routes: caffeine covers the tiredness signal, alcohol sedates and blocks the cycle. What matters is that the liver takes time to clear them, that each person takes a different amount of time, and that with age it takes longer. This is why an afternoon coffee costs some people their night, while for others a glass of wine at dinner quietly dismantles it. If you are sensitive, watch chocolate at night too.

Move during the day. It is one of the things that most helps sleep at night, and some consider it the single most important item on this list. You do not need to train; you need to not spend the day sitting.

Give your mind an hour or two to come down. No screens, no work, no arguments. For many people — especially anyone carrying unaddressed anxiety — this is the one that changes the most.

Use the bedroom only for sleeping. Let the brain associate that place with sleep and not with working, arguing or staring at a screen. Take the desk and the television out if you can.

Do not eat late. Although if you wake in the small hours abruptly with your heart racing, it may be a drop in blood sugar: in that case a slowly digesting carbohydrate before bed often helps you stay asleep.

Block the noise. Good earplugs solve more nights than people expect.

Lower the electromagnetic fields. Turn the wifi off at night, leave the phone in aeroplane mode and away from the bed. The source this chapter follows attributes this to the effect of those fields on circulation; whatever the mechanism, there are sensitive people who sleep noticeably better this way, and trying it costs nothing.

Keep a sleep journal. Write down how much you slept and what you did that day: what you ate, at what time, what you drank. It is the simplest way to find what is taking your sleep, and something almost always turns up.

And check for sleep apnoea. It affects a large share of the population and wrecks the cycle without the person noticing: if you snore heavily, wake unrefreshed, or your partner notices you pausing in your breathing, that needs looking at.

Melatonin: use it carefully

Melatonin is useful for resetting the clock once it has been knocked out of place — jet lag is the clear case — taken a few hours before sleep. But it is not a nightly sleeping pill. Two warnings. The first is about quality: many supplements on the market do not contain the melatonin they claim. The second is more fundamental: continuous long-term use may end up dysregulating the pineal gland, which is precisely the gland that should be producing it on its own. Use it deliberately and occasionally, not out of habit. See Chapter 15.

To learn more (sources in English)

This chapter draws on two articles by A Midwestern Doctor, which cite many studies: the first on why there is no cure for insomnia, and “Stopping the War Against Sleep” of 9 August 2026, which expands on it and is the source of most of the figures in this chapter.

The FDA's war against sleep: https://www.midwesterndoctor.com/p/why-isnt-there-a-cure-for-insomnia