Science says sleep is essential for brain health, but just how important is it? At Sömn, it’s no secret that we all function much better after a good night’s sleep. Our bodies feel more robust. Our memories are clear and sharp. Perhaps most importantly, we’re alert and emotionally present for those who love and depend on us.
According to the latest research, sleep may even help clear out toxins linked to conditions like Alzheimer’s, but it has to be the right kind of sleep. Deep sleep is what the brain needs for optimal health and wellness.
A lot of the cutting-edge research on brain health and sleep comes from Dr. Lisa Mosconi, associate professor of neurology and radiology at Weill Cornell Medicine and Director of the Women’s Brain Initiative and Alzheimer’s Prevention Program. She is also the author of ‘The XX Brain,’ ‘Brain Food,’ and ‘The Menopause Brain.’
Even as experts like Dr. Mosconi strive to fully understand the benefits and mechanisms of sleep, there’s already a lot of evidence about the mental and physical problems caused by a lack of rest. Some of the connections include depression, heart disease, and diabetes. Overall, we have plenty of reasons why it’s never a good idea to skimp on sleep!
Scientists have classified sleep into two types—rapid eye moment (REM) and non-rapid eye movement (NREM). We all go through these cycles about five times a night, about every ninety minutes.
Deep sleep, also known as slow wave sleep, happens in the third stage of NREM— this is what’s critical for brain health, according to Dr. Mosconi, who calls this phase the brain’s “me time.” When the body is almost perfectly still, the brain cells, called neurons, fire less often. During this slow-wave activity (SWA), brain waves are more predictable. This is when the cerebrospinal fluid, the liquid around the brain and spinal cord, flows in and out of the brain, flushing it almost like a car wash, removing toxins, byproducts, and waste products, including Alzheimer’s fragments.
When we’re awake, our brain waves are fast and frenetic, regulating body functions and responding to the various stimuli in our environment. During deep sleep, the brain mostly tunes out the outside world, so much so that it can be challenging to wake up during this time, even in response to loud noises. Anyone abruptly awakened understands the feeling of groggy disorientation as our motor and sensory performance struggle to catch up, a psychological state called sleep inertia.
About 20% of all our sleep will be deep sleep. However, this can be impacted by age and diet. Those over 65 may only benefit from about 30 minutes of deep sleep. Moreover, factors like caffeine and alcohol can be interruptive, leading us to wake up in the middle of the night, so the process must start all over again.
Overall, the quality of our sleep affects the whole body and contributes to many factors vital to health and wellness:
- A robust immune system
- Memory
- Learning
- Cardiovascular health
- Tissue and muscle repair
- Hormonal balance
- Metabolism
Sleep’s immense importance to mental and physical health is driving a wave of research. For example, experts are examining how frequencies like white noise may enhance deep sleep. Even tech companies have jumped onboard, releasing apps that claim to track and monitor sleep patterns.
Science could eventually produce breakthroughs, but for now, healthy sleep comes down to good hygiene and small, consistent efforts: a warm bath before bed, regular exercise—even pyjamas and bed linens that support healthy rest. It’s really about what we need to feel at ease and relaxed individually.
So, how do we know if we’re getting enough sleep? The best and easiest method is simply assessing how we feel after waking up. Our bodies are sophisticated. The brain will let us know if we’re getting enough deep sleep by how we feel and function.
We just have to learn to listen.