Jumping into sub-zero water is often memorable. Sometimes, it’s grounds for an epiphany. When Dr Chris Van Tulleken plunged into the Arctic Ocean, it was both.
‘I was next to an iceberg and I had an overwhelming feeling of vertigo, of sea creatures being below me and polar bears within reach,’ says the TV presenter, doctor and researcher at University College London. ‘As soon as I got out, I wanted to do it again immediately and I felt wonderful for days afterwards. It’s such a strong physical stimulus. That was the moment that prompted me to call researchers and ask “is there any science behind this?”‘
As it turned out, there is some – but not enough. The topic hit the headlines last month when a Case Report in the British Medical Journal described the improvement in symptoms of depression of a young woman who followed a programme of outdoor swimming in water at 15 degrees centigrade. The patient, Sarah, who appeared in Van Tulleken’s BBC series The Doctor Who Gave Up Drugs, stopped taking medication by the end of the trial.
The report on her experience was co-authored by Van Tulleken, along with research scientists Professor Michael Tipton and Dr Heather Massey of the University of Portsmouth, and the OSS’s very own expert medical advisor Dr Mark Harper of Brighton and Sussex Medical School.
It is thought there is likely to be a range of explanations for why outdoor swimming can improve symptoms of depression. Depression is a stress response and exposing the body to a new source of stress can improve how a person’s system deals with existing stressors – a process known as cross-adaptation.
More familiar explanations are also likely to play a role: the post cold water ‘high’; the experience of being outdoors; and belonging to a community of swimmers.
Beyond understanding how cold water immersion can improve depression, further research may also enable a better understanding of depression itself.
‘We understand very little about it,’ says Van Tulleken. ‘Depression has genetic influences but we haven’t specifically identified them; it’s probably not one disease but many; there are environmental and lifestyle factors, and these may be physical or psycho-social. Factors like deprivation, local social hierarchy and level of autonomy in life all play a role. If cold water swimming is effective it may help us understand how depression works’.
That’s why the team at the University of Portsmouth and Brighton are calling on members of the Outdoor Swimming Society to gather a range of testimonies about the benefits of cold water swimming – not only in improving depression and anxiety, but also how it has improved conditions including arthritis, migraines, MS and migraines.
‘We want to gather experiences of people who have done it so we can go to funders and say there are grounds for research and interest in doing so,’ says Harper. ‘The experiences of Outdoor Swimming Society members are exactly what we need – people who have used cold water swimming for various conditions’.
‘Writing the case report was starting at the bottom in terms of scientific evidence. The next stage is a pilot to see if we can persuade people to do it – to join the pilot and stick with it. Then a randomised control trial, in which we could combine exercise, cold baths and outdoor swimming’.
The research reflects a merging of the personal and professional for most of the team. Massey is a lifelong sea swimmer and completed a double crossing of the Channel as part of a relay team this summer. Her work usually focuses on the dangers of cold water immersion, leading to a recent collaboration with the RNLI on the ‘Float to Live’ campaign.
‘Since the case study was published and reported, quite a lot of people have got in touch with similar experiences,’ she says. ‘There’s a weight of scientific evidence about the negative effects, so we’re trying to redress the balance’.
Harper adds: ‘The first time I got out of the water and thought “oh, this feels good” was 14 years ago. But we have to be objective. It’s certainly not for everyone, but for some people – and I think a significant number – it works’.
Indeed, the only disadvantage of gathering robust evidence of this nature is that cold water swimmers will no longer be able to enjoy their reputation for being somewhat eccentric cultural outliers. “But everyone likes to be right, don’t they?” says Van Tulleken.