The APOE4 sleep protocol that took my REM from 12% to 20%+

Most advice treats sleep as one more healthy habit. For us it's load-bearing. Two findings changed how I think about it. First, carriers show reduced REM sleep — lower percentage and duration — even without any cognitive symptoms [Andre et al., 2024]. "I feel fine" doesn't mean your sleep architecture is fine. Second, sleep problems and APOE4 are synergistic, not additive : in a 2024 study, the group with both had higher plasma NfL — a marker of neurodegeneration — than either factor alone [Yu et al., 2024]. The mechanism is the part that stuck with me. Your brain clears waste, including amyloid-beta, through the glymphatic system — and that clearance drops about 90% when you're awake [Gaur et al., 2022], with slow-wave (deep) sleep being when the clear-out happens [Lee et al., 2020]. One honest caveat: much of the glymphatic mechanics are mapped in animal models, with human evidence still building. But the direction is consistent — deep sleep is the power-wash, and we can't afford to skip it.