Sleep and longevity

Did you know that someone who lives to 90 spends an average of about 32 years asleep? That may seem like a lot, but sleep is not a waste of time. It is one of the most active recovery processes your body has. During your sleep, there is intense work on repair, renewal, and balance. And there is growing evidence that good sleep also contributes to a longer and healthier life.

In this article, you’ll read how sleep affects your health and your longevity. We explain what happens when you sleep, why the sleep cycle and REM sleep are important, and how you can improve your sleep quality.

What happens when you sleep?

Although your consciousness takes a break, your body is actually hard at work. Every night, all kinds of processes take place that contribute to your recovery:

• Muscle and tissue recovery: During deep sleep, damaged cells are repaired and growth hormone is produced. Important for recovery after exercise or illness.
• Building the immune system: At night, your body produces immune cells and anti-inflammatory substances. Sleep deprivation can disrupt this process and make you more susceptible to infections.
• Tissue and muscle recovery:
  During deep NREM sleep, damaged tissues are repaired, muscle cells are built, and growth hormone is released. This makes sleep essential for physical rejuvenation and recovery, especially after exercise or illness.
  
• Cell renewal & immune system:
  At night, your body produces immune cells and cytokines that fight infections and reduce inflammation. Chronic sleep deprivation suppresses this immune function and makes you more susceptible to illness.
  
• Brain cleansing (glymphatic system):
  During sleep, your brain flushes out waste products such as beta-amyloid—a protein linked to Alzheimer’s. This natural detox process is only active during deep sleep.
  
  
• Memory, learning & emotional processing:
  During REM sleep, your brain processes information, stores memories, and organizes emotions. Sleep deprivation disrupts these processes, leading to mood swings, forgetfulness, and concentration problems.
  
• Cardiovascular recovery:
  During sleep, your blood pressure and heart rate drop. This literally gives the heart a moment of rest, which reduces the risk of cardiovascular disease.
  
• Hormonal balance:
  Sleep regulates, among other things, ghrelin (the hunger hormone), leptin (satiety), and cortisol (the stress hormone). Poor sleep → more hunger, more stress, greater chance of weight gain.
  
• Circadian rhythm synchronization:
  Your internal clock determines, among other things, your energy level, appetite, and mood. Sleep keeps this rhythm in balance. Disrupted sleep also disrupts your biological clock, similar to chronic jet lag.
  
• Skin & appearance
  During sleep, collagen is produced, blood flow to the skin improves, and oxidative damage is repaired. Lack of sleep accelerates skin aging → wrinkles, dull complexion, sagging.

How does the sleep cycle work? 

Sleep occurs in cycles averaging 90 minutes. Each night, you go through several of these cycles. Each cycle consists of four stages:

1. Phase 1 (light NREM): your body relaxes and your breathing slows.
2. Phase 2 (light NREM): your heart rate and body temperature decrease.
3. Phase 3 (deep NREM): physical recovery, cell renewal, and immune function.
4. Phase 4 (REM sleep): dreaming, memory processing, and emotional regulation.

For optimal sleep, it’s important to go through these cycles uninterrupted. Waking up often or having trouble falling asleep disrupts this process.

The sleep cycle and REM sleep

A good night’s sleep consists of multiple sleep cycles of about 90 minutes each. During such a cycle, you go through four stages, from light sleep to deep sleep and finally REM sleep. In deep sleep, most physical recovery processes take place, while the REM stage is especially important for your memory, creativity, and emotional balance.

You need several of these cycles per night to truly feel well-rested. If you often wake up or have trouble falling asleep, you lose valuable time in those deeper sleep stages. 

5 practical tips to improve your sleep quality

A good night’s sleep doesn’t start only with what you do at night, but precisely with the choices you make during the day and in the evening. Small adjustments to your lifestyle can already make a big difference in how quickly you fall asleep and how rested you wake up.

Based on scientific insights, there are a number of practical strategies that can support your sleep quality. Below you’ll find five actionable tips that contribute to a better sleep rhythm and a deeper, more restorative night’s sleep.

1. Start your day with daylight

Exposure to natural daylight in the morning is one of the most effective ways to support your biological clock and improve your sleep. Light signals through your eyes stimulate the suprachiasmatic nucleus (a small area in the brain that functions as your biological clock), which regulates your circadian rhythm.

Morning light helps suppress melatonin production during the day and ensures that this sleep hormone is produced on time in the evening. This promotes a natural sleep rhythm, helping you fall asleep faster and sleep more deeply.

Research shows that people who get more exposure to daylight in the morning experience better sleep quality and have fewer sleep problems. Outdoor light (even on a cloudy day) is much more effective for this than indoor artificial light.

2. Avoid screens before bedtime

Using smartphones, tablets, and laptops in the evening can make it harder to fall asleep. This is mainly due to exposure to blue light, which suppresses melatonin production.

Studies show that people who use screens before bedtime fall asleep later, experience less deep sleep, and feel less rested the next day. In addition, the mental stimulation from, for example, social media or work-related content keeps your brain active when it should be winding down.

Avoiding screens in the last hour before going to sleep is therefore a proven strategy to improve your sleep quality.

3. Sleep in a cool, dark room

Your sleep environment directly affects how quickly you fall asleep and how deeply you sleep. An important part of this is temperature. To sleep well, your body temperature needs to drop slightly. A cool bedroom (about 16–19°C) supports this process and helps you fall asleep faster.

Darkness is also essential. Even small amounts of light can disrupt melatonin production and affect your sleep cycle. Research shows that exposure to light at night can lead to more fragmented sleep and fewer deep-sleep stages.

A dark, quiet, and cool environment is therefore one of the most effective ways to improve your sleep quality in a lasting way.

4. Maintain a consistent evening routine

A fixed evening routine helps your body prepare for sleep. By going to bed around the same time every night and repeating familiar relaxing habits, you train your brain to associate sleep with these cues.

In science, this is also applied in treatments such as cognitive behavioral therapy for insomnia (CBT-I), where consistency and sleep rhythm are central. Research shows that consistent bedtimes and routines contribute to falling asleep faster and better sleep quality.

In addition, a calm evening routine helps lower stress levels and brings the nervous system into a relaxed state, which is essential for a good night’s sleep.

5. Support your sleep with magnesium (L-threonate)

Magnesium L-threonate is getting increasing attention because of its effects on the brain and sleep quality. Unlike many other forms, this variant was developed with the aim of crossing the blood–brain barrier, making magnesium more directly available to brain cells. Research shows that magnesium L-threonate may contribute to improvements in cognitive performance and sleep quality. 

Magnesium L-threonate is an innovative form specifically developed with absorption in the central nervous system in mind. Recent studies, including a placebo-controlled trial (Hausenblas et al., 2024), show positive changes in sleep duration and perceived sleep quality.

Because sleep is closely linked to brain processes such as memory and the glymphatic system, magnesium L-threonate is increasingly being seen as a targeted supplement within a modern sleep routine.

What is the best bedtime?

There is a review study (Chaput et al., 2018) that looked at how much sleep people need at different ages.¹ The researchers conclude that there is no “one size fits all” for sleep duration. People differ greatly in how much sleep they need to feel energetic during the day. Those who get enough sleep wake up well-rested and function better throughout the day.¹

The study also emphasizes that, in addition to the amount of sleep, the quality, regularity, and the time you go to bed are just as important.¹

Newborns sometimes sleep as much as 17 hours a day. Adults need an average of 7 to 9 hours. In older adults, sleep is often less deep, but that doesn’t mean they need less sleep.

Is 6 hours enough? For most people, no. You’re then probably getting too little deep sleep or REM sleep. So it’s not just about the number of hours. Regularity and quality also play a major role. People who go to bed at different times all the time, look at screens a lot before going to sleep, or are bothered by light and noise often feel less well-rested.

What is the effect of sleep on longevity?

In a large study of more than 172,000 people, conducted by the American College of Cardiology, it was found that good sleep habits are associated with a higher life expectancy²Men with five healthy sleep habits lived an average of 4.7 years longer. For women, this was 2.4 years.

What were those five habits?

• 7–8 hours of sleep per night
• No trouble falling asleep or staying asleep
• No sleep medication
• Waking up rested (at least 5 times per week)

According to the researchers, 8% of all deaths in the study population could be linked to poor sleep. They also emphasize that more research is needed, especially into differences between men and women.

Sleep as an investment in yourself

Good sleep is not an extra. It is just as important as eating, drinking, and exercising. Yet it is often underestimated. Many people still see sleep as something you “can catch up on” or “less important than being productive.” But that is a misconception. Sleep supports almost every system in your body. Your brain, your heart, your immune system, and even your skin recover at night.

What does this mean for Longevity? Sleep is also important for healthy aging. It supports your recovery, immune resilience, memory, and energy level. Not sleeping, or sleeping too little, leaves its mark in the long run.

Sources 

1. Chaput, J.-P., Dutil, C., & Sampasa‑Kanyinga, H. (2018). Sleeping hours: What is the ideal number and how does age impact this? Nature and Science of Sleep, 10, 421‑430. https://doi.org/10.2147/NSS.S163071

2. American College of Cardiology. (2023). Getting Good Sleep Could Add Years to Your Life. https://www.acc.org/About-ACC/Press-Releases/2023/02/22/21/35/Getting-Good-Sleep-Could-Add-Years-to-Your-Life
   
   
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