Research

Hormonal

Human immune function exhibits significant seasonal variation, with a pro-inflammatory transcriptomic profile and increased circulating levels of risk biomarkers (sIL-6R, CRP) during winter months in temperate climates.

If you live in a temperate climate, your immune system is biologically wired to be more inflammatory in winter. This is an evolutionary adaptation, not just a reaction to germs. Be aware that this internal shift may increase your baseline risk for inflammatory conditions during winter months, regardless of your lifestyle choices.

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With regards to tissue function, the immune system has a profound pro-inflammatory transcriptomic profile during European winter, with increased levels of soluble IL-6 receptor and C-reactive protein, risk biomarkers for cardiovascular, psychiatric and autoimmune diseases that have peak incidences in winter.
Xaquín Castro Dopico et al. · Nature Communications · 2015

Why this rating

Large sample sizes across multiple cohorts (Germany, UK, Australia, US, Iceland, Gambia) with replicated findings.

Source

Widespread seasonal gene expression reveals annual differences in human immunity and physiology

Xaquín Castro Dopico et al. · Nature Communications · 2015

DOI 10.1038/ncomms8000

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DOI resolved against Crossref · corpus check 2026-06-10

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