Sleep Deprivation: New Insights about The Brain’s Hidden Cleaning Crisis

By Ram Rao, Ph.D., Principal Research Scientist for Apollo Health

A groundbreaking 2025 MIT study has uncovered something both unsettling and illuminating: after just one night of poor sleep, the brain begins cleaning itself during wakefulness, and each time it does, attention and focus momentarily collapse. Deprived of deep-sleep maintenance, the brain forces “micro cleaning cycles” throughout the day, slipping into brief sleep-like states to compensate, and each time it does, your attention temporarily collapses. Using simultaneous fast fMRI and EEG in 26 adults, the researchers observed large, slow waves of cerebrospinal fluid (CSF) sweeping across the brain during wakefulness, identical to the waves seen only in deep sleep. These daytime cleaning cycles unfolded in a precise sequence: (1) attention drops first, (2) 0.5 to 2.5 seconds later the CSF surges outward, (3) after 6 to 8 seconds the surge wave peaks, and (4) attention returns. Every CSF cleaning wave corresponded with a measurable lapse, missed cues, slowed reaction time, pupil constriction, and changes in breathing and heart rate.  In short, “the brain goes into a cleaning mode at the cost of your focus and attention, whether or not it is convenient for you”.

Why This Matters: The Science Behind These “Attention Blackouts”

Have you ever read the same line three to five times after a sleepless night, or found your car drifting as your eyes briefly closed, or blanked out mid-conversation? These are not moments of “zoning out.” They are micro-maintenance intrusions, where the brain momentarily diverts resources from attention to cleanup. During deep sleep, the glymphatic system expands to flush out toxic proteins such as amyloid-β and tau, as well as other metabolic waste. When sleep is inadequate, the brain attempts this cleanup anyway, but in fragmented, inefficient bursts during the day, thereby compromising attention, productivity, and safety.

The Glymphatic System: The Nightly Detox Pathway: Discovered in 2012, the glymphatic system is the brain’s waste-clearance network. During deep sleep:

• Cell spaces expand by ~60%
• Fluid flow increases 10 to 20-fold
• Clearance of Alzheimer’s-related proteins doubles

Poor sleep quality or insufficient sleep can raise amyloid and tau levels by 35 to 55%, and even a single sleepless night can increase amyloid burden by as much as 5%. This is why the study findings are critical: daytime “emergency cleaning” cannot replace the efficiency of deep sleep. Many studies now show that chronic poor sleep is emerging as one of the major modifiable risk factors for accelerated cognitive aging.

Ensuring a Good Night’s Sleep

Multiple factors contribute to poor sleep during midlife, including but not limited to shift work, deadlines, caregiving, stress, anxiety, and lifestyle habits. Some are beyond our control, but many are not. If you routinely get only four to five hours of sleep due to late-night work or screen use, it may be time to re-examine these patterns. Otherwise, the long-term risks, including cognitive decline by retirement age, become very real. A consistent, restorative night’s sleep supports the brain’s clearing and repair functions and is essential for memory consolidation and long-term resilience.

At Apollo Health, quality sleep is foundational to the KetoFLEX 12/3 Lifestyle. We recommend getting 7 to 8 hours of quality sleep each night. Our Sleep guide, available to all our ReCODE and PreCODE members, offers evidence-based strategies, sleep hygiene practices, tools, and aids to help you optimize your nightly rest.

A New Year Focus: Reclaiming Your Sleep

As we step into the New Year, there is no better and no more scientifically grounded resolution than prioritizing both the quantity and quality of your sleep. With new insights showing how profoundly sleep shapes attention, mood, metabolism, and long-term cognitive health, making sleep a non-negotiable part of daily self-care may be the single most powerful investment you make in your brain this year. Here’s to beginning the year with calmer nights, clearer days, and a healthier brain for life.