Topic
Circadian rhythm
Everything we've written on Circadian rhythm — 7 articles covering the mechanism, the evidence, comparisons, and practical considerations.
7 articles
Sleep and recoveryThe chronobiology of aging — how time-of-day biology shifts across decadesIn October 2017, the Nobel Committee awarded its Prize in Physiology or Medicine to three American scientists — Jeffrey Hall, Michael Rosbash, and Michael Young — for work they had been doing since the 1980s in fruit flies. The work seemed, at the time, like beautiful basic science. They had identified the molecular machinery that makes biological clocks tick: not just the observation that living things have circadian rhythms, but the actual gears — the genes, the proteins, the feedback loops that generate a 24-hour oscillation at the cellular level. The prize recognized that this machinery is conserved across nearly all forms of life, that it is present in every human cell, and that its disruption underlies an array of conditions whose connection to time-of-day biology had not previously been obvious: metabolic disease, cancer risk, neurodegeneration, immune dysfunction, mood disorders.12 min readSleep and recoveryClock genes and the molecular machinery of circadian rhythmsIn 1971, a Caltech neurobiologist named Seymour Benzer and his student Ronald Konopka did something that looked, at the time, like a footnote. They exposed fruit flies — Drosophila melanogaster — to a chemical mutagen and then watched what happened to the flies' behavior. Normal flies follow a precise 24-hour activity rhythm: active during the day, inactive at night, eclosing from their pupal cases at a consistent circadian time. Some of the mutant flies lost this rhythm entirely. Others ran on 19-hour cycles. Others ran on 28-hour cycles. Benzer and Konopka mapped all three behavioral mutations to the same genetic locus, which they named period. It was the first identification of a gene controlling behavior — a gene that, when altered, didn't change what the animal did but when it did it.11 min readSleep and recoveryWhy melatonin stops working after 40You started with half a milligram and it worked. Then it worked less well and you moved to one milligram, then three, then five, then ten — the gummy your partner saw on the nightstand that said ten milligrams on the label as if that were a reasonable thing to put in a gummy. And sleep has gotten worse, not better, or marginally better in a way that doesn't match the dose escalation. And somewhere in the background is a nagging sense that you're doing something wrong but you don't know what because melatonin is natural and natural means safe.7 min readSleep and recoveryMelatonin discovery — how a frog skin extract became the world's most-taken sleep aidIt was 1958, and Aaron Lerner was working with a problem that had nothing to do with sleep. The Yale dermatologist was trying to understand what caused certain skin diseases — vitiligo in particular, the condition that removes pigment from patches of skin in irregular, spreading patterns. He had a hypothesis: somewhere in the body, there was a substance that acted against melanin. Where melanin darkened the skin, this hypothetical compound would lighten it. He called it, before he'd found it, a melanocyte-lightening substance. And he believed, based on older papers suggesting the pineal gland had some relationship to skin pigmentation in frogs, that the pineal might be where it lived.10 min readCognitive supportWhat people are reporting about PinealonThis article summarizes experiences reported in public online communities including Reddit, longevity forums, and discussion boards. We are not advocating human use of any compound discussed here. Many of the peptides discussed are not FDA-approved for the uses described, and some are explicitly not approved for human or veterinary use. What follows is a synthesis of what people have reported, presented to give readers context on the public conversation — not as guidance, not as evidence of safety or efficacy, and not as a recommendation. Decisions about any compound should be made with a qualified prescribing provider after a full medical evaluation.8 min readSleep and recoveryCan't stop thinking at night — the racing mind that comes only after darkYou're tired. Genuinely tired — you've been tired since two in the afternoon. By nine o'clock you're doing that thing where you fall slightly asleep on the couch and then jolt awake and decide to go to bed. You brush your teeth, lie down, turn off the light. And then, as if a switch has been thrown in exactly the wrong direction, your mind begins. Tomorrow's calendar, reconstructed in detail. The thing you said in the meeting that landed slightly wrong. A worry scenario about something that probably won't happen but could. An idea — actually a good idea — that you'd really rather not lose. The mental traffic moves through at full alertness, and the body that was exhausted twenty minutes ago is now lying rigid in the dark, fully online.8 min readSleep and recoveryThe shift worker's body — the physiology of working against your circadian biologyYou work nights, or rotating shifts, or the kind of irregular schedule that means your body never quite settles into a pattern. You're a nurse who works three twelve-hour nights and then has four days off, which sounds reasonable until you realize what four days off costs your nervous system when it tries to flip back to human daytime. Or you're a firefighter on a 24-48 schedule, going forty-eight hours of normal life followed by a shift that might involve serious exertion at three in the morning. Or you're an ER physician who pulls nights every third week, a factory worker on rotating days and nights, a long-haul trucker whose schedule is dictated by load availability rather than anything biological. The work is necessary. The people who do it are providing services that run the infrastructure of modern life. And their bodies are paying a price that the occupational health literature has been documenting for decades, a price that most shift workers recognize in the gut but haven't fully accounted for.9 min read