Cold showers, ice baths, and "cold plunges" have become one of the wellness world's most popular habits over the past few years. Most coverage frames this around mood and circulation; the connection to autophagy — the cell's own self-cleaning mechanism — rarely gets a deeper look. A small but notable study out of the University of Ottawa, published in 2025, suggests cold exposure may have a measurable effect at the cellular level.
Let's be clear upfront: this isn't evidence that "ice baths extend your lifespan." The study is small, short, and conducted only in young men. But it offers real, verifiable early data on what might be happening at the cellular level — and read without the hype, that's a genuinely interesting starting point.
The study was led by Glen Kenny at the University of Ottawa, with Kelli King and James McCormick, and published in Advanced Biology in 2025. Researchers immersed 10 healthy young men, aged 20-26, in 14°C water for 1 hour a day, 7 days in a row. Blood samples were drawn on days 1, 4, and 7, and markers of autophagy and apoptosis (programmed cell death) were measured in white blood cells (peripheral blood mononuclear cells, or PBMCs).
The findings showed a U-shaped adaptation pattern: early in the exposure period, cells showed signs of autophagic dysfunction alongside increased apoptotic signaling — in other words, the body was mounting a stress response in the first few days. By the end of day 7, the picture reversed: autophagic activity increased while apoptotic and inflammatory signaling declined. The researchers interpreted this as a sign that repeated cold exposure makes cells more resilient to stress over time.
Autophagy is the cell's internal "cleanup" process, breaking down and recycling damaged proteins, misfolded molecules, and dysfunctional cell components (see our article on autophagy). This process tends to slow with age, which can let damaged material accumulate inside cells — a buildup linked to several age-related diseases. Whether cold exposure belongs on the list of interventions known to trigger autophagy, alongside fasting, exercise, and calorie restriction, is exactly the question this study set out to ask.
A 2025 review in Life Sciences (Boulares, Jdidi, and Douzi) takes a broader look at the cold exposure-longevity link. The review reports that cold exposure can lower chronic inflammation, strengthen antioxidant defenses, and improve metabolic health by activating brown adipose tissue. The authors also point to data from hibernating mammals and model organisms, where lower environmental temperatures have been observed to correlate with longer lifespans.
But the review doesn't present this as settled evidence — quite the opposite. It explicitly notes that long-term human lifespan data remains very limited, and that the potential risks of extended cold exposure, particularly in older adults, remain a serious open question for research.
The reasonable takeaway here: there's a real, early-stage signal that cold exposure triggers a cellular adaptation response — but turning that into a prescription like "take cold showers regularly and live longer" would need much larger, much longer human studies. For someone who already has a cold shower or brief cold exposure routine and no cardiovascular contraindications, there's no data suggesting the habit is harmful. But treating it as a standalone "longevity intervention" on the strength of this study alone would be getting ahead of the evidence.
Ease into cold water gradually, don't push past your limits, and get out immediately if you feel chest pain, shortness of breath, or dizziness. Anyone with cardiovascular disease, uncontrolled blood pressure, or Raynaud's syndrome, and anyone pregnant, should talk to a doctor before starting such a routine — these groups weren't part of the study population.
We don't know yet. The most concrete data is a small study of 10 young men showing 7 days of cold water exposure increased autophagy at the cellular level. That's not evidence of extending lifespan — it's an early finding that a cellular mechanism changed.
Autophagy is the cell's cleanup mechanism, breaking down and recycling damaged or dysfunctional components. It tends to slow with age, letting damaged material build up. Interventions known to trigger autophagy, like fasting and exercise, draw interest in longevity research for this reason.
In the study, participants were immersed in 14°C water for 1 hour a day, 7 days in a row — not a routine for everyday life, but a controlled research protocol. Whether shorter cold shower routines produce the same effect is unknown.
Anyone with cardiovascular disease, uncontrolled blood pressure, Raynaud's syndrome, or who is pregnant should check with a doctor first. A sudden cold shock can trigger sharp changes in heart rate and blood pressure.
Not directly — the study only included young men. Preliminary findings from the same group's not-yet-fully-published thesis work suggest older adults may respond more weakly, but this isn't a settled conclusion yet.
"A study of ten people doesn't give us a definitive answer — but seeing cells measurably adapt to cold within a week is a signal worth following up with larger studies."
— Vivelong Longevity Science Team