Cold Water Immersion

Last fall I succumbed to a whim that seems to be sticking (like beekeeping) and went full gusto with it. I had read “What Doesn’t Kill Us” by Scott Carney about lessons learned from cold-immersion expert Wim Hoff (why didn’t I just get the Wim Hoff book? I don’t know but I guess I should), whose methods Mr. Carney initially thought would be a bunch of bunk. I mean none of us actually believe in alternative medicines anyway, right? I ask this in all seriousness, because generally speaking, I don’t.

That said, it’s undeniable that humans have evolved to endure environmental stressors that have all but been eliminated since the advent of automobiles, air-conditioning, and desk jobs. Our dependence on recreational fitness for health purposes is a tacit confession that our cushy lifestyles might not be the best for bodies that evolved to chase prey and jump into cold water on the regular.

Enter the cold water immersion trend. The idea is that regular immersion in cold water is not only refreshing and exhilarating, but apparently activates growth of an organ (like our skin is an organ) known as Brown Adipose Tissue (“BAT”) or brown fat. It’s usually only found in babies and young children, and tends to disappear as we age, unless we encourage its growth with activities like cold immersion, exercise, and even caffeine intake. But cold immersion seems to be most effective at stimulating brown fat because brown fat converts energy into heat most efficiently, unlike stubborn white fat (the “fat” we tend to associate with obesity).

Brown fat is so powerful in its protective qualities that it can even protect an otherwise obese person, or someone carrying a lot of white adipose tissue. This became clear to me when I noticed that many of the open-water swimmers I routinely saw when doing big mile+ Pacific ocean swims in years past not only weren’t wearing wetsuits; they were often the least “athletic” looking of the bunch, carrying extra weight around the middle. They were also some of the fastest swimmers, coming in first in their age group nine times out of ten.

How are these cold swimmers living longer with fewer health problems than their thinner peers? The answer just may be cold water immersion. But don’t take my word for it. Here’s a list of studies detailing the benefits of cold water immersion:

• Cold water immersion may protect against dementia. Source: Cambridge University, 2020.
• Cold showers can treat depression. Source: Med Hypothesis, 2008.
• Brown adipose tissue is associated with cardiometabolic health. Individuals with higher BAT had lower odds of type 2 diabetes, dyslipidemia, coronary artery disease, cerebrovascular disease, congestive heart failure and hypertension, even in otherwise obese individuals, for whom the presence of BAT was especially beneficial. Source: Nature Medicine, 2021.
• One negative I found in my research, from 2014, was a correlation between large amounts of BAT and incidence of breast cancer, possibly because of the high vascular nature of BAT, which theoretically could feed tumor blood supply (my nutshell takeaway from the article, but what do I know? Next to nothing). Source: BMC Cancer journal, 2014.
• However, other studies point to cold immersion as a method of possible anti-tumor immunity. Source: National Library of Medicine/National Institute of Health, 2007.

So try it if you like, and tell me you don’t find it oddly addicting. But first speak with your doctor (legal disclaimer! Remember I used to be a lawyer, not a doctor) and make sure you have another person nearby, because cold water swimming can be dangerous. Cold water shock is real and can cause cardiac arrest, and often the worst effects are felt after you’re out of the water: it’s called afterdrop but I call it “the shakes.”

Thanks for looking, and happy dipping. 🙂 xo