By LUKE ANDREWS SENIOR HEALTH REPORTER FOR DAILYMAIL.COM
Published: 10:42 EDT, 2 April 2025 | Updated: 10:43 EDT, 2 April 2025
Ice baths and polar plunges could fight off disease and even slow aging — but there's a catch.
A small study suggests that in order to reap the benefits of subjecting yourself to painfully low temperatures, you have to stay in the cold water for an hour.
Researchers in Canada tracked 10 young men who were immersed in an ice bath for 60 minutes a day for seven consecutive days.
Blood samples were taken before and after the immersion, and were then analyzed in a lab to assess cellular health.
Cells showed a boost in their autophagic system, the cellular 'recycling' system that breaks down and reuses old parts, which boosts longevity.
Analysis of blood biomarkers also showed that there was a reduction in inflammation and cellular damage.
'We were amazed to see how quickly the body adapted,' said physiologist at the University of Ottawa Dr Kelli King who lead the study.
'Cold exposure might help prevent diseases and potentially even slow down aging at a cellular level. It's like a tune-up for your body's microscopic machinery.'
Ice baths can help to reduce aging in cells, a study suggests (stock image)
Ice baths and polar plunges — or swimming in cold open water — have surged in popularity in recent years amid claims they can reduce inflammation and stress and boost someone's overall health.
Plunging into the cold water triggers the body's cold shock response, where a sudden drop in skin temperature leads to a surge in adrenaline, noradrenaline and other hormones that boost feelings of alertness and raise body temperature.
This process is believed to be behind the alleged health benefits, although scientists warn that not everyone may benefit from the baths.
Those taking ice baths risk suffering from hyperventilation and hypothermia, which can be deadly.
In the most recent study, researchers recruited 10 active young men who had no underlying health conditions to use the ice baths.
They were 23 years old on average, had a BMI in the healthy range and a body composition that was 17 percent body fat.
The participants were immersed in water that was 57.2 degrees Fahrenheit (14 degrees Celsius) for an hour. They were in a seated position with the water level going up to their shoulders.
this temperature is about average for an ice bath, but well-below that of a swimming pool, which usually hovers around 78F (25.5C). The time was also much longer than than the typical recommendation for an ice bath, which is normally about five to ten minutes.
Each participant was required to use the ice bath once a day for a week and had a thermometer inserted into their throat to measure their internal temperature.
Blood samples were taken on days one, four and seven of the experiment.
Over time, the exposure to the cold water day after day was associated with improvements in cells' autophagy, or recycling, system.
Physiologist Dr Glen Kenny, who was also involved in the study, added: 'Our findings indicate that repeated cold exposure significantly improves autophagic function, a critical cellular protection mechanism.
'This enhancement allows cells to better manage stress and could have important implications for health and longevity.'
The scientists suggested that the stress from the cold water led to the boost in cell function.
They added that more research was needed, saying this was only a small study on young men.
The paper was published in the journal Advanced Biology.