Sleep is the foundation upon which other pillars of health stand. That’s according to Dr. Matthew Walker, Professor of Neuroscience and Psychology, Director of the Center for Human Sleep Science at the University of California, Berkeley, and author of the international bestseller Why We Sleep: Unlocking the Power of Sleep and Dreams. His growing body of data suggests that 7 to 9 hours of good sleep every night is important for effective immune function, regulating metabolism, as well as controlling glucose and its mechanisms in appetite and weight gain. Lack of sleep is also a risk factor for illness from minor colds to serious diseases such as cancer and Alzheimer’s. Says Walker, “The biggest misconception is that our bodies are dormant during sleep, and this couldn’t be further from the truth.”

Sleep is the single most effective thing that you can do to reset your brain and body health every day. The shorter your sleep, the shorter your life. It’s the elixir of life and the Swiss army knife of health.

During sleep, our body undergoes a remarkable overhaul of all of its physiological systems—cardiovascular, immune, metabolic, hormonal, and in the brain. Dr. Matthew Walker’s research shows that deep sleep is when our body’s sewage cleansing system kicks into high gear. Our brain literally washes away all of the metabolic byproducts that build up when we’re awake. This is a particularly important function as it relates to dementia and Alzheimer’s Disease. Our heart rate slows down with more benefits than any blood pressure medication could ever offer. Sleep also stimulates many immune factors that help fight off infections. In addition, deep sleep is when our brain processes information and commits it to long term memory. It can also contribute to good mental health and creativity. Thus, all night cramming for a test or brainstorming for a presentation won’t serve you as well as a good night’s sleep.

All of this begs the question—how do we get a good night’s sleep in our non-stop demanding lives? Aside from more complex sleep disorders, Dr. Walker says there are several simple steps for ensuring sleep. These include a regular sleep schedule, a dark and cool room without our devices, stopping caffeine intake after midday, and staying away from alcohol. Alcohol induces sedation but causes fragmented sleep. Furthermore, if you’re having trouble falling asleep, Dr. Walker suggests getting up for a short while and then returning to bed.

With so much at stake, why aren’t we prioritizing sleep more? Says Walker, “Sleep is the neglected stepsister in the health conversation of today, but getting sleep tonight is literally an investment in tomorrow. Sleep is probably mother nature’s best effort yet at immortality.”