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Phoenix APOE4 Research · Reviewed by Kevin Tran, APOE4/4 carrier and founder · Data through 2026-08-23 · How to read this research
How to read this
Observational research: real APOE4 carriers tracked over time, each compared with their own earlier self. Members chose their interventions, with no randomisation or placebo group. Everything else they changed is shown beside each result.
Read the full methods and limitsPhoenix has measured Morning caffeine against 2 exact outcomes for APOE4 carriers. Deep plus REM sleep was 3 minutes lower at one tagged day and 8 minutes lower among 24 members with at least ten tagged days. One curated member rated morning-caffeine sleep lower while another felt no change despite a wearable-stage decline.
| Outcome | Direction | What we observed |
|---|---|---|
| Deep plus REM sleep | Opposite direction | Deep plus REM sleep was 3 minutes lower at one tagged day and 8 minutes lower among 24 members with at least ten tagged days. |
| Subjective sleep quality | Mixed results | One curated member rated morning-caffeine sleep lower while another felt no change despite a wearable-stage decline. |
Phoenix has measured Morning caffeine against 2 exact outcomes for APOE4 carriers. Deep plus REM sleep was 3 minutes lower at one tagged day and 8 minutes lower among 24 members with at least ten tagged days. One curated member rated morning-caffeine sleep lower while another felt no change despite a wearable-stage decline.
Deep plus REM sleep was 3 minutes lower at one tagged day and 8 minutes lower among 24 members with at least ten tagged days. Support: 43 logged members, 24 members with repeats, 2 observations.
One curated member rated morning-caffeine sleep lower while another felt no change despite a wearable-stage decline. Support: 2 logged members, 2 members with repeats, 2 observations.
Search by health goal or intervention to see what changed for real members, including results that moved the wrong way.
Morning caffeine · 2 outcomes shown.
Deep + REM sleep: Decrease 8 min
Repeat members: 24Average
Deep plus REM sleep was 3 minutes lower at one tagged day and 8 minutes lower among 24 members with at least ten tagged days.
Morning caffeine
↘Opposite directionDeep plus REM sleep was 3 minutes lower at one tagged day and 8 minutes lower among 24 members with at least ten tagged days.
Morning-caffeine days carried 111 fewer minutes of deep plus REM sleep.
What else changed: no nearby starts were recorded.
Next study: A placebo-controlled crossover found dose and clock time mattered, supporting explicit dose-and-time capture instead of one blanket caffeine label.
Morning-caffeine days carried 82 fewer minutes of deep plus REM sleep while felt sleep was unchanged.
What else changed: no nearby starts were recorded.
Next study: A placebo-controlled crossover found dose and clock time mattered, supporting explicit dose-and-time capture instead of one blanket caffeine label.
A placebo-controlled crossover found dose and clock time mattered, supporting explicit dose-and-time capture instead of one blanket caffeine label.
Sleep quality: Mixed result Mixed
Cases: 2
One curated member rated morning-caffeine sleep lower while another felt no change despite a wearable-stage decline.
Morning caffeine
✓ / ↘Mixed resultsOne curated member rated morning-caffeine sleep lower while another felt no change despite a wearable-stage decline.
Her subjective sleep rating dropped on morning-caffeine days.
What else changed: no nearby starts were recorded.
Next study: repeat Subjective sleep quality after a dated Morning caffeine window.
Her subjective sleep rating was unchanged despite lower wearable deep plus REM sleep.
What else changed: no nearby starts were recorded.
Next study: repeat Subjective sleep quality after a dated Morning caffeine window.
The 43-page study: what members tried, how their bloodwork and wearable results changed, and what else changed alongside them.
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