Sleep, Circadian Rhythm and Inflammaging: How Disrupted Sleep Accelerates Biological Aging

Every night, sleep runs a maintenance program most people never think about. It is not just rest. It is the window in which the body clears inflammatory byproducts, repairs damaged tissue, and disposes of cells that should no longer be dividing. When that window is disrupted, chronically and repeatedly, the process that keeps low-grade inflammation in check starts to fail. Researchers call this failure inflammaging, and it is now understood as one of the core drivers of biological aging. Circadian disruption does not just cost you a good night's sleep. It changes how fast your immune system ages.

Sleep is one piece of a much bigger picture. For the full breakdown of how chronic inflammation drives biological age, see chronic inflammation and inflammaging explained.

The circadian clock as an inflammation regulator 

Your body runs a 24-hour biological program. The master clock sits in the suprachiasmatic nucleus (SCN), a small region of the brain that coordinates peripheral clocks distributed across virtually every organ and cell type: the liver, the heart, skeletal muscle, and immune cells. These clocks do not just regulate when you feel sleepy. They regulate the daily rhythm of inflammatory activity itself, timing when the immune system ramps up to detect threats and when it stands down to repair.

The SCN is set primarily by light and darkness, but the peripheral clocks also respond to meal timing and physical activity, meaning the whole system depends on multiple signals arriving in the correct sequence. At the molecular level, this rhythm is enforced by two core clock proteins, BMAL1 and CLOCK, which act as switches controlling immune cell activity throughout the day. Under normal conditions, the immune system cycles between a daytime phase oriented toward threat detection and an overnight phase focused on resolution and repair. When the clock falls out of sync, that cycle breaks down, and the immune system gets stuck in a state of persistent low-grade activation. This is the molecular starting point of inflammaging, and it produces no obvious symptoms while it is happening.

The inflammaging mechanism: how sleep loss triggers cytokine leakage 

Under a healthy circadian rhythm, pro-inflammatory signaling is switched on during the day and stood down overnight. Disrupted sleep interferes with that shutdown. Inflammatory cytokines, most notably interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), begin to leak into circulation at times when they should be suppressed. Over time, this is not an isolated spike. It becomes a baseline shift, a body that runs slightly hotter, immunologically, than it should.

The evidence for this already sits in the existing research base. When researchers compared two groups of mice losing the same amount of sleep, the ones whose light-dark cycle was disrupted to simulate shift work developed measurable inflammatory changes. The group that simply slept less, with no timing disruption, did not. In human studies, just three days of an inverted sleep schedule were enough to produce measurable increases in inflammatory markers, with nothing else changing. Timing, not duration, is the variable driving the leak.

"Short bursts of inflammation are extremely important. They eliminate pathogens. But when inflammation becomes a long-term chronic state, it leaves microscopic molecular scars, because inflammation is always destruction. The immune system comes in, destroys the threat, and repairs the damage, and even that process costs a huge amount of energy. As we age, we become more and more pro-inflammatory, and through years or even decades of this low-grade chronic process, what we identify as disease develops."

— Prof. Gordan Lauc, Co-Founder and Chief Scientific Officer, GlycanAge; Professor of Biochemistry and Molecular Biology, University of Zagreb

Cellular senescence: when the body stops cleaning house 

Cytokine leakage is only half the mechanism. The other half is what disrupted sleep does to the body's cleanup process. During deep sleep, the body runs autophagy, the process by which cells break down and recycle damaged internal components. Autophagy is one of the primary mechanisms for clearing cells that have become senescent, cells that have stopped dividing but refuse to die, sometimes called zombie cells. 

Senescent cells are not passive. They secrete their own cocktail of inflammatory signals, a process researchers call the senescence-associated secretory phenotype, which includes many of the same cytokines elevated by circadian disruption. When sleep is chronically disrupted, autophagy is impaired, senescent cells accumulate faster than they are cleared, and those cells actively worsen the inflammatory environment they were supposed to be removed from. This is a feedback loop: disrupted sleep drives inflammation, inflammation drives senescence, and senescence drives more inflammation.

The nightly repair window: deep sleep, REM, and the inflammatory reset 

Not all sleep contributes equally to this repair process. Deep, slow-wave sleep is when autophagy and tissue repair are most active, and REM sleep plays its own role in immune regulation and cytokine balance. This is part of why timing matters as much as total hours. A schedule that technically delivers eight hours but repeatedly disrupts when those hours fall can shortchange the deep-sleep-heavy early cycles that do most of the inflammatory reset work, even without shortening total sleep time. 

The GlycanAge connection: from inflammatory spikes to biological age 

Cytokine leakage and senescent cell accumulation are difficult to observe directly. Glycans offer one of the few practical windows into this process. Immunoglobulin G (IgG) glycosylation patterns shift in response to the immune system's inflammatory state, which is why GlycanAge testing tracks three primary glycan structures: Glycan Youth and Glycan Shield, associated with immune protection and tolerance, and Glycan Mature, associated with pro-inflammatory activity. When circadian disruption pushes the immune system toward chronic low-grade activation, that shift shows up in the glycan profile, often before any symptom would.

A case from GlycanAge testing illustrates this. A 61-year-old former nurse, with more than 30 years of career including decades of rotating shifts, came in for testing ten years after retiring. By the time of the test, her lifestyle was genuinely good: Mediterranean diet, regular exercise, consistent sleep timing, and hormone replacement therapy, which typically shifts the glycan profile in an anti-inflammatory direction. Nothing in her current habits should have flagged a problem. Her glycan profile disagreed. Biological age was elevated, Glycan Youth and Glycan Shield were low, and Glycan Mature was high. Cardiovascular, metabolic, autoimmune, and respiratory domains all came back slightly out of range. It looked like the immune system was still carrying the imprint of years of circadian disruption, more than a decade after the disruption itself had ended.

This is the core distinction GlycanAge testing offers. It does not measure how many hours you slept last night. It measures whether years of accumulated inflammatory exposure, including the kind driven by circadian disruption, have changed the trajectory of how your immune system is aging.

Why circadian disruption is a systemic risk 

The scale of this exposure is easy to underestimate. Shift work alone affects a substantial share of the global workforce, and most people are not aware of what the research says about it. Most people have never heard that shift work is classified as a probable carcinogen. In 2007, the International Agency for Research on Cancer placed it in the same risk category as occupational painting and firefighting, based on what chronic circadian disruption does to the body over time. Circadian disruption is also associated with increased risk of cardiovascular disease, metabolic dysfunction, obesity, depression, and cognitive decline, and many of these risks are driven by the timing misalignment itself, independent of how much total sleep someone gets. 

Realigning your clock: a longevity protocol 

Reversing circadian-driven inflammaging is not immediate. It takes months to years, not weeks, because it depends on rebuilding the consistency the clock needs to run its repair cycles properly.

Light exposure: Morning light within an hour of waking is one of the strongest signals available for resetting the master clock and supporting the daytime-to-repair transition. Dim light and reduce screen exposure for two to three hours before bed, and sleep in genuine darkness to protect the deep-sleep window where autophagy is most active.

Sleep timing: A fixed wake time, held within a 30-minute window daily, stabilizes the clock proteins that govern the daily inflammatory cycle more effectively than sleep duration alone.

Meal timing: The body clock responds to food timing as much as light. Keeping meals within a 10 to 12-hour daylight window supports the fasting period the overnight repair process depends on.

Diet: A Mediterranean dietary pattern supports the anti-inflammatory glycan structures that decline with circadian disruption. Omega-3 supplementation at 1 to 2 g of EPA/DHA daily has been shown to reduce pro-inflammatory glycan modifications.

Supplemental support for circadian repair 

Low-dose melatonin, 0.3 to 1 mg taken three to five hours before usual sleep time, works by shifting the clock rather than sedating, directly supporting resynchronization rather than just inducing sleep. Magnesium glycinate or L-threonate, 200 to 500 mg before bed, supports sleep quality and cortisol modulation. Glycine, 3 to 5 g before bed, lowers core body temperature and has improved sleep quality in controlled trials. L-theanine, 100 to 200 mg in the evening, helps where an overactive mind is the primary obstacle. Tart cherry extract and apigenin from standardized chamomile extract offer additional, lower-intensity support for sleep duration and mild sedation. 

Age reversal, not just fewer sick days 

The goal of realigning your circadian rhythm is not simply avoiding illness. It is interrupting a mechanism that, left unaddressed, quietly compounds: disrupted sleep drives cytokine leakage, cytokine leakage drives senescent cell accumulation, and senescent cells drive more inflammation, all of it accelerating how fast the immune system ages. That process is reversible, but it has to be measured to be managed. 

"Circadian health is fundamental to immune health. GlycanAge provides the means to measure it, track it, and intervene before the damage becomes permanent."

— Bruno Butorac, BSc, Specialist & Education Coordinator, GlycanAge

A GlycanAge test tracks how this kind of chronic inflammatory exposure has shaped your biological age, and our team can help you build a personalised plan to realign your biology and protect your long-term health. 

Ready to find out how your immune system is really aging? Shop the GlycanAge test and get your first measurable read on your biological age. 

External sources

• https://www.jstage.jst.go.jp/article/jphs/118/2/118_11R04FM/_article — Bannai M, Kawai N. Glycine improves the quality of sleep. J Pharmacol Sci. 2012;118(2):145–148. 

• https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0063752 — Brager AJ, Ehlen JC, Castanon-Cervantes O, Natarajan D, Delisser P, Davidson AJ, Paul KN. Sleep loss and the inflammatory response in mice under chronic environmental circadian disruption. PLoS ONE. 2013;8(5):e63752.

• https://pubmed.ncbi.nlm.nih.gov/41176609/ — Cotter J, Caddick CE, Harper JL, Ebajemito JK. L-theanine and sleep: systematic review. Nutr Neurosci. 2026;29(2):224–238. 

• https://pubmed.ncbi.nlm.nih.gov/20148687/ — Dibner C, Schibler U, Albrecht U. The mammalian circadian timing system: organization and coordination of central and peripheral clocks. Annu Rev Physiol. 2010;72:517–549. 

• https://di.aerzteblatt.de/int/archive/article/78451 — Erren TC, Morfeld P, Foster RG, Reiter RJ, Gross JV, Westermann IK. Shift work and cancer: the evidence and the challenge. Dtsch Arztebl Int. 2010;107(38):657–662. 

• https://pubmed.ncbi.nlm.nih.gov/30046148/ — Franceschi C, Garagnani P, Parini P, Giuliani C, Santoro A. Inflammaging: a new immune-metabolic viewpoint for age-related diseases. Nat Rev Endocrinol. 2018;14(10):576–590. 

• https://www.sciencedirect.com/science/article/pii/S2590142724000193?via%3Dihub — Hausenblas HA, Lynch T, Hooper S, Shrestha A, Rosendale D, Gu J. Magnesium L-threonate improves sleep quality. Sleep Med X. 2024;8:100121. 

• https://pubmed.ncbi.nlm.nih.gov/12076414/ — Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database Syst Rev. 2002;(2):CD001520. 

• https://link.springer.com/article/10.1007/s00394-011-0263-7 — Howatson G, Bell PG, Tallent J, Middleton B, McHugh MP, Ellis J. Tart cherry juice and sleep quality. Eur J Nutr. 2012;51(8):909–916.

• https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(19)30455-3/abstract — IARC Monographs Volume 124 Group. Carcinogenicity of night shift work. Lancet Oncol. 2019;20(8):1058–1059. 

• https://pubmed.ncbi.nlm.nih.gov/24325898/ — Krištić J, Vučković F, Menni C, Klarić L, Keser T, Beceheli I, et al. Glycans are a novel biomarker of chronological and biological age. J Gerontol A Biol Sci Med Sci. 2014;69(7):779–789. 

• https://pubmed.ncbi.nlm.nih.gov/1394610/ — Lewy AJ, Ahmed S, Jackson JML, Sack RL. Melatonin shifts human circadian rhythms according to a phase-response curve. Chronobiol Int. 1992;9(5):380–392. 

• https://pubmed.ncbi.nlm.nih.gov/27885005/ — Man K, Loudon A, Chawla A. Immunity around the clock. Science. 2016;354(6311):434–439. 

• https://pubmed.ncbi.nlm.nih.gov/26858430/ — Morris CJ, Purvis TE, Hu K, Scheer FAJL. Circadian misalignment increases cardiovascular disease risk factors in humans. Proc Natl Acad Sci USA. 2016;113(10):E1402–E1411. 

• https://pubmed.ncbi.nlm.nih.gov/27885007/ — Panda S. Circadian physiology of metabolism. Science. 2016;354(6315):1008–1015. 

• https://pubmed.ncbi.nlm.nih.gov/12970302/ — Rajaratnam SMW, Dijk DJ, Middleton B, Stone BM, Arendt J. Melatonin phase-shifts human circadian rhythms. J Clin Endocrinol Metab. 2003;88(9):4303–4309. 

• https://www.cell.com/current-biology/fulltext/S0960-9822(12)00325-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982212003259%3Fshowall%3Dtrue — Roenneberg T, Allebrandt KV, Merrow M, Vetter C. Social jetlag and obesity. Curr Biol. 2012;22(10):939–943. 

• https://www.cell.com/current-biology/fulltext/S0960-9822(16)30187-7?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982216301877%3Fshowall%3Dtrue — Roenneberg T, Merrow M. The circadian clock and human health. Curr Biol. 2016;26(10):R432–R443. 

• https://www.nature.com/articles/nri3386 — Scheiermann C, Kunisaki Y, Frenette PS. Circadian control of the immune system. Nat Rev Immunol. 2013;13(3):190–198. 

• https://www.dovepress.com/magnesium-bisglycinate-supplementation-in-healthy-adults-reporting--peer-reviewed-fulltext-article-NSS — Schuster J, Cycelskij I, Lopresti A, Hahn A. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep. Nat Sci Sleep. 2025;17:2027–2040. 

• https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(07)70373-X/abstract — Straif K, Baan R, Grosse Y, et al. Carcinogenicity of shift-work, painting, and fire-fighting. Lancet Oncol. 2007;8(12):1065–1066. 

• https://link.springer.com/article/10.1186/1472-6882-11-78 — Zick SM, Wright BD, Sen A, Arnedt JT. Chamomile extract for insomnia. BMC Complement Altern Med. 2011;11:78.