Why the cold weather might be very good for your health
Exposure to cold activates brown fat which acts as a 'furnace for the body:' researcher
This winter, when the cold Canadian arctic wind embraces you give it a hug right back. The cold, cold weather may be very good for your health, according to new research from the University of Ottawa and the University of Sherbrooke.
CBC Hamilton's Conrad Collaco spoke with Denis Blondin a post-doctoral fellow at the University of Sherbrooke, and a researcher in thermal physiology. Blondin says his research has shown extended exposure to the cold has a number of positive health effects because it helps the body build brown fat, which is a tissue that burns a lot of energy and acts as a "furnace for the body".
Click on the image at the top of this page to listen to the full interview or read the edited and abridged transcript below. It might even make you learn to love the winter.
Denis Blondin, researcher in thermal physiology at the University of Sherbrooke
Q: What made you want to study the effect of the cold on the human body?
Initially we were looking at how we could improve the odds of survival and how we could perform in a cold environment. We started to realize there might be some therapeutic benefits to cold exposure. We started a collaboration with the University of Laval, the University of Sherbrooke and the University of Ottawa to look at the effects of a mild cold exposure. We looked at this one particular tissue called brown fat. Brown fat is found in all mammals and it's primary function is to produce heat. It is activated by cold.
In most rodents we noticed it not only helps to defend them against the cold it helps them to defend against obesity and diabetes. We wanted to see if a similar trend could be seen in humans.
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Q: How did you conduct the experiments?
We used a cooling suit, basically a spandex suit that has tubes running through it. We circulate cold water through it to create that cold environment. Water tends to be between four and eighteen degrees Celsius. It was the equivalent of being outside in late fall in a t-shirt and shorts.
Q: Once you had them wrapped in this cold water suit what did you have them do?
They were sitting on a chair or lying down on a bed or watching a video or doing work or reading a book. After they get over the initial shock of the cold they adjust quickly and function normally.
Q: And what did you learn about how the body reacts to cold temperatures?
When we are exposed to cold environments our body has to increase the amount of calories it burns off to produce heat. If we didn't react that way our core temperature would fall over time. We do that by recruiting our muscles to shiver a little or by recruiting brown fat which acts like a mini-furnace.
This heat production is sustained by using fat that we have in circulation or fat we have in different tissues or by using glucose. For people who are obese or diabetic there tends to be an over supply of glucose in circulation which tends to be stored in tissues where it can have damaging affects. Through cold exposure we can have that glucose go into the active tissues and be burnt off rather than being stored.
Once the brown fat has been stimulated, which can only be done through cold exposure, the brown fat will take up some of the glucose and then burn it off.
Q: Is this weight loss without exercise? Just go out into the cold?
This is where things get tricky. Cold exposure can increase the number of calories we are burning and the amount of fat we are using but we tend to compensate. Cold also makes us hungry. Cold exposure, like exercise, isn't something we can use on its own. We can use it to burn calories as part of a plan that includes proper nutrition and exercise.
Q: If someone was going to use your research in the next few winter months what should they do?
Assuming that you are keeping your calorie intake the same and are not overeating after cold exposure you can decrease the temperature of your house, wear fewer layers when you go outside or reduce the heat in your car. You are letting your body adjust to the temperature rather than changing your environment.
Q: Can what you have discovered be used as a therapy for people who have diabetes?
It has that potential. It is still early days. It can be used in combination with exercise and proper nutrition or even replace exercise in situations where exercise might not be advisable. It could work in conjunction with exercise. Swimming in a colder pool might result in more calories burned than in warmer water.