By David Blyweiss, M.D., Advanced Natural Wellness
February 26, 2021
Ever seen those crazy people who do polar bear plunges?
They’re not hard to find. In fact, if you head to Canada on New Year’s Day, you’ll find them leaping into the icy waters near their homes.
But this practice isn’t just for our neighbors up North.
A Polar Bear Plunge event in Maryland in 2007 raised a whopping $2.2 million for the Special Olympics. The number of people who jumped into those frigid waters… 7,400!!
Honestly, these folks are onto something really smart. In fact, I perform a similar practice each year…
I don’t actually do a polar bear plunge — it’s a little hard when you live in Florida — but I do expose my body to extremely low temperatures.
It’s a treatment called cryotherapy where my whole body (except for my head) is encased in a cold therapy unit.
The set up looks like something you’d see in a science fiction movie. Imagine standing in a giant round refrigerator with a hole in the top for your head to stick out.
The health benefits can actually be really great… especially when it comes to increasing the levels of brown fat in your body.
Good Fat and Bad Fat in Your Body
Many people don’t know this, but your body actually has two kinds of fat tissue — white and brown. White fat (also known as white adipose tissue or WAT) is your dominant form of fat.
Brown fat (or brown adipose tissue – BAT) is a little harder to come by. It has a special property where it creates heat when it burns through a process called thermogenesis.
So, if you have a creature that can’t shiver for warmth — like a newborn baby for instance — the burning of brown fat creates heat to keep them warm.
This tissue is called “brown fat” because it’s filled with mitochondria that are filled with a lot of iron. The fat cells are actually darker in color.
People used to think that fat tissue was simply there to store excess calories. But over the past few decades, scientists now understand that fat cells act more like an organ. They release free fatty acids and hormones which act on other tissues in your body.
For instance, leptin is a hormone released by fat cells to act on the brain, liver and muscles to regulate food intake, energy balance and insulin sensitivity.
As you get older, your levels of brown fat naturally go down and white fat takes over. Then, white fat distribution can affect your risk of metabolic diseases especially if you have a lot of it around your abdomen.
However, there are a few ways to encourage the growth of new brown fat cells.
And one of the best ways… is to be COLD.
That’s why the temperature in my home is lowered to 64 degrees each night when I head to bed. When you expose your body to colder temperatures, you recruit more brown fat cells to keep you warmer.
Some people will get their daily cold exposure through a cold shower or an ice bath. Or, if it’s cold outside, head out without bundling up quite so much.
It’s also possible to increase your levels of brown fat through exercise and calorie restriction. Still, your levels will never be quite as high as when you were a young child.
This whole idea explains why people who live the longest often live in the mountains. People who are regularly exposed to cold temperatures have more brown fat and improved levels of insulin sensitivity. 
You don’t want to be cold all the time though.
Instead, try for repetitive or intermittent cold exposure (ICE). It’s a more realistic approach so you can activate your brown fat cells.
So, if you’re hoping to combat obesity, look for ways to activate your brown fat cells. Try regular cold exposure and add in more exercise.
 Cannon B, Nedergaard J (2004) Brown adipose tissue: function and physiological significance. Physiol Rev 84: 277–359
 Aherne W, D Hull: Brown adipose tissue and heat production in the newborn infant. J Pathol Bacteriol 91(1), 223-234 (1966)
 Puri V, Virbasius JV, Guilherme A, Czech MP. RNAi screens reveal novel metabolic regulators: RIP140, MAP4k4 and the lipid droplet associated fat specific protein (FSP) 27. Acta Physiol (Oxf) 2008;192:103–115.
 Gesta S, Tseng YH, Kahn CR. Developmental origin of fat: tracking obesity to its source. Cell. 2007;131:242–256.
 Bukowiecki, L., Collet, A.J., Follea, N., Guay, G. & Jahjah, L. Brown adipose tissue hyperplasia: a fundamental mechanism of adaptation to cold and hyperphagia. Am. J. Physiol. 242, E353–E359 (1982).
 van Marken Lichtenbelt, W.D., Hanssen, M.J., Hoeks, J. et al. Cold acclimation and health: effect on brown fat, energetics, and insulin sensitivity. Extrem Physiol Med 4, A45 (2015). https://doi.org/10.1186/2046-7648-4-S1-A45
 Harri M, Dannenberg T, Oksanen-Rossi R, Hohtola E, Sundin U (1984) Related and unrelated changes in response to exercise and cold in rats: a reevaluation. J Appl Physiol Respir Environ Exerc Physiol 57: 1489–1497.