Be Incredible Bites:

• Poor sleep quality predicts mortality more than sleep duration.

• REM sleep is critical for longevity and health.

• Long hours in bed with poor-quality sleep can shorten lifespan.

Sleep Quantity vs. Quality

You might think sleeping longer means better health. However, studies show that it’s sleep quality – not quantity – that predicts lifespan.

Matthew Walker explains that while getting less than 7 hours of sleep increases health risks, sleeping more than 9 hours also correlates with higher mortality. But it’s not the extra sleep that’s harmful.

“The reason is that people who sleep longer often have poor sleep quality,” Walker clarifies. These individuals may stay in bed longer to compensate for fragmented, low-quality sleep.

REM Sleep Is the Key to Longevity

A Harvard study confirmed that REM sleep, not just deep sleep, is the best predictor of mortality. When researchers placed non-REM and REM sleep side by side in statistical models, REM sleep was the stronger indicator of health outcomes.

“The less REM sleep you had, the worse your mortality risk,” Walker says. The relationship was linear – the more REM sleep you lose, the higher your risk of dying prematurely.

Why Longer Sleep Can Be Misleading

If someone consistently sleeps 9-10 hours but wakes up tired, the culprit is likely poor sleep efficiency. This leads to:

• Increased risk of cardiovascular disease

• Weakened immune system

• Higher rates of neurodegenerative diseases

Boosting Sleep Quality for a Longer Life

To improve your sleep quality and longevity:

• Prioritize REM sleep by reducing alcohol and caffeine.

• Create a dark, cool sleeping environment.

• Track your sleep to identify patterns.

Better quality sleep, even if shorter, can significantly improve your health and extend your life.