Sleep: A Free and Simple Way To Extend Your Lifespan
Longevity's Little-Known Shortcut
Most people’s favorite topic (after a good meal) is optimizing for a good night’s rest— and for good reason. Sleep has long been associated with overall health and longevity.
First, let’s discuss ‘what is sleep.’ It’s more interesting than you might think. Sleep is a complex physiological state not merely characterized by reduced awareness of the external environment and diminished physical activity. During sleep, the brain goes through several stages, each with distinct patterns of neural activity. These stages are essential for various cognitive and restorative functions.
For instance, synaptic homeostasis, a process where unnecessary neural connections are pruned, predominantly occurs during sleep, optimizing brain function and memory consolidation.
In fact, one of the most well-researched functions of sleep is its role in memory consolidation. During wakefulness, the brain encodes and stores new memories in the hippocampus, a region involved in short-term memory. During sleep, particularly during non-rapid eye movement (NREM) sleep, these memories are replayed and transferred to the neocortex, a region involved in long-term memory storage.
This process strengthens neural connections and integrates new memories with existing knowledge. This reminds me of how neuroplasticity works, namely the ability of the brain to reorganize itself by forming new neural connections throughout life. This ability allows neurons (nerve cells) to adjust their activities in response to new situations or to changes in their environment, for instance, when a patient suffering an incomplete spinal cord injury has spasms during exercises while learning to walk, again. I have a family member overcoming this very experience.
Synaptic plasticity, similarly, refers to the brain's ability to rewire and strengthen or weaken synapses (connections between neurons) based on experience and learning. Sleep, especially REM sleep, is believed to play a critical role in synaptic plasticity, optimizing the brain's neural networks. The relationship between sleep and the brain cannot be overstated.
Remove and Restore
Our brains consume a significant portion of the body's energy, mainly in the form of glucose. Sleeping well allows the brain to restore its energy reserves. Adenosine, a byproduct of cellular energy consumption, accumulates in the brain during wakefulness and contributes to the feeling of sleepiness. Sleep helps in clearing adenosine, ensuring that the brain is energized and alert upon waking. This is also why a good night’s rest makes us feel “good.”
REM sleep, in particular, has been associated with emotional regulation. During this sleep phase, the brain processes and integrates emotional experiences, which can help in reducing emotional reactivity and enhancing emotional resilience. A deficit in REM sleep can lead to increased emotional reactivity and reduced ability to cope with emotional challenges. Chronic sleep disruption can lead to imbalances in neurotransmitter activity, potentially resulting in mood disorders, cognitive impairments, and other neurological issues, particularly dementia.
Recent discoveries have shed light on the brain’s “waste clearance system” I mentioned earlier, known as the glymphatic system. This system becomes particularly active during sleep, allowing cerebrospinal fluid to flow more freely through brain tissues and remove waste products, including potentially harmful proteins like beta-amyloid, which is implicated in Alzheimer's disease. A lack of sleep could impede this clearance process, potentially contributing to neurodegenerative disorders. In fact, some research suggests that “impaired sleep represents one of the earliest symptoms of Alzheimer’s disease.”
Hormones
When the deep stages of (NREM) sleep occur, there is also a surge in the release of growth hormone. This hormone plays a pivotal role in cellular growth, metabolism, and repair. Lack of adequate deep sleep can lead to a decrease in growth hormone secretion, which could potentially hamper tissue repair and regeneration. This can accelerate the aging process and contribute to age-related diseases. This is because sleep isn’t just about resting, but rebuilding.
At a cellular level, sleep is a period of restoration. When you’re asleep, your cells engage in repair processes, including DNA repair and the clearance of metabolic waste products. Chronic sleep deprivation can lead to an accumulation of cellular damage, including oxidative stress, which in turn can accelerate cellular aging and increase the risk of age-related diseases.
It bears repeating that chronic sleep deprivation can lead to an increased risk of various health issues, including cardiovascular diseases, diabetes, obesity, and even all-cause mortality. Recent research indicates that individuals who consistently get fewer than six hours of sleep per night have a higher risk of premature death compared to those who receive seven to eight hours. Not good for those of us seeking optimal healthspan.
There is extensive research on the intricate relationship between sleep and the immune system, as well. As the above study suggests, sleep and circadian rhythms have a profound effect on immune function. During nocturnal sleep, there's a rise in undifferentiated naïve T cells and pro-inflammatory cytokines. On the contrary, immune cells with immediate effector functions, like natural killer cells, peak during the day.
This redistribution and extrava
sation of T cells during sleep might suggest an enhanced immune surveillance and a more efficient immune response following potential exposure to pathogens. Chronic sleep deprivation could lead to an imbalanced immune function, making individuals more susceptible to infections and possibly reducing the efficacy of immune responses to vaccines.
Sleep Well
In essence, sleep is not just a passive state but an active and restorative process that profoundly impacts health, cellular aging, and longevity. Ensuring adequate and quality sleep should be paramount in any health and longevity strategy. Again, the relationship between sleep and the brain should be emphasized, especially in the context of healthy aging. In a study I mentioned earlier, entitled “Sleep Quality and Aging: A Systematic Review on Healthy Older People, Mild Cognitive Impairment and Alzheimer’s Disease,” discussing the early signs of AD and impaired sleep, goes on to say that a “total of 71 studies were included, and the whole sample had a mean age that ranged from 58.3 to 93.7 years (62.8–93.7 healthy participants and 61.8–86.7 pathological populations).
“Of these selected studies, 33 adopt subjective measurements, 31 adopt objective measures, and 10 studies used both. Pathological aging showed a worse impoverishment of sleep than older adults, in both subjective and objective measurements. The most common aspect(s) compromised in AD and MCI (mild cognitive impairment) were REM sleep, sleep efficiency, sleep latency, and sleep duration. These results underline that sleep alterations are associated with cognitive impairment.”
So how can we improve our sleep to improve our health, or at least to enjoy the comfort of rest? I can speak about what works for me. There are a litany of lists one could find online, which all boil down to the similar advice: don’t eat and drink before bed, keep the room cool, et al. I’ll share what has worked for me. I don’t use alarms to wake up, for instance, as the disturbance, as mentioned, might be linked to impairment. I also don’t wear pajamas to bed. I also gave up the identity of being a “nightowl,” and effectively “hacked my chronotype” by increasing my physical intensity per day. I walk a minimum of 10,000 steps everyday, whether it’s a gym day or not (non-gym days are much higher), and I eat lots of protein, despite eating one meal per day.
Here are 10 things I do to optimize my sleep:
Sleep cold (66-68 degrees) with a HEPA filter.
Sleep in the least amount of clothing (bamboo underwear and tank)
Comfortable mattress, gel pillow, cover / duvet only (no sheet)
Pitch black room
High Intensity Interval Training (HIIT)
Always shower before bed
Minimize food and fluid 2-3 hours before bed (except grass-fed jerky, which kills nightmares)
No eating, drinking, or tech, in the bedroom. No negotiations!
Deep breathing, meditation, prayer, just before sleeping
Wake up naturally
Goodnight.