We truly are in the heart of winter. Arctic winds, torrential rain and the fact that we can see our breath as soon as we step outside makes us want to do one thing: get back inside where it’s warm and cozy.
However, new research suggests that being subjected to regular mildly cold temperatures may be an easy and healthy way of reducing weight, according to first author Wouter van Marken Lichtenbelt of the Dutch Maastricht University Medical Center, published in January’s edition of the scientific journal, Trends in Endocrinology & Metabolism.
He believes that the continued use during the winter months of central heating in our homes and offices could be a contributing factor to the widespread obesity around the country.
Along with his team, van Marken Lichtenbelt began studying the effects of mild cold exposure over a decade ago. Speaking during a public press release of their findings to Cell Press, van Marken Lichtenbelt felt that, seeing as we spend 90 per cent of our time indoors, it was important to analyze the health effects of this common lifestyle, as well as the fact that the subject had received very little attention within the scientific world.
They hypothesized that the environmental temperature does have an effect on human health, with the team arguing that frequent exposure to mild cold temperatures had a long term and sustained effect on energy use (i.e. calories burned) in humans.
Whenever science has delved into the effects of environmental temperature on humans, it has always been to extreme measures, notably for military and firefighting purposes. Seeing as few of us actually encounter these temperatures, research into more common ambient temperatures was undertaken, and it was noted that people have a wide range of responses when it comes to dealing with mild cold.
The scientific community then discovered the reason: brown fat.
Brown fat was associated with babies, being particularly abundant in newborns. Also known as brown adipose tissue (BAT), this type of fat cell has the peculiarity of being able to generate heat without shivering, as our muscles do, when exposed to the cold, and is typically found on the back of newborn infants.
It is much more metabolically active than subcutaneous fat, requiring a rich supply of oxygen and energy to be able to generate the heat.
Newborns require this self generating heat source, as they often lack the musculature necessary to sustain shivering, as well as having an inability to move out of the cold and a still developing nervous system that means they are unable to respond as quickly to varying temperatures as an adult would.
It turns out that adults also have this type of adipose tissue, however in varying quantities depending on the person, which explained the aforementioned range of responses to mild cold as seen by previous research. When exposed to the cold, those with higher levels of brown adipose tissue were able to generate more heat than others, effectively feeling warmer.
Van Marken Lichtenbelt now argues that there is sufficient evidence to suggest that a varying, fluctuating indoor temperature, which follows the dynamic nature of outside temperatures, could have a significant benefit on our health.
A Japanese team found that people subjected to 17 degrees Celsius for two hours a day during a six week period showed a reduction in body fat.
This agrees nicely with results from the Dutch team’s research, showing that after spending six hours a day for ten days in the cold, the individuals in the experiment increased their total brown adipose tissue percentage and shivered less when exposed to cold temperatures, portraying the body’s resilient nature as it began to get used to the cold.
In younger individuals, such heat production from brown fat can account for up to 30 percent of energy use.
The researchers are keen to point out that more tests should be run in the future to examine the exact effects of colder climes on the human body.
It could be beneficial, therefore, to resist turning on the central heating earlier as it gets colder, or spend your lunch break outside rather than inside, if you are looking to shed a few of the leftover Christmas pounds.
How will you use the colder temperatures to your advantage this winter?