Michael Mosley: Why turning down your thermostat could be good for your health
With winter bringing colder and shorter days, your natural reaction might be to keep as warm as you can. But as Dr Michael Mosley discovers in his new 麻豆社 Radio 4 podcast series, Cold Therapy, carefully embracing lower temperatures can benefit your health and wellbeing.
In the first episode of the series, Michael discovers how turning your thermostat down by just a few degrees can improve your fat and blood sugar metabolism, boost your mood, and may even protect you against type 2 diabetes and cardiovascular disease.
Shivering is nature鈥檚 central heating
Your body wants to maintain its temperature at around 37°C, which it does through various mechanisms including shivering. When you shiver, your muscles are burning calories from sugar or fat to produce heat, which helps keep your core temperature stable.
Participants were on average around 40% better at controlling their blood glucose levels.
“Of course, that has its limitations,” says Hannah Pallubinsky, Assistant Professor at Maastricht University. “It's quite uncomfortable and it costs the body a lot of energy. So, you don't want to keep shivering too much!”
At cooler temperatures your body starts to adapt to the cold and can even start to thrive
In studies carried out by Pallubinsky and her team, participants spent six hours a day for ten days at 14 to 15°C. Pallubinsky noticed that, after a while, participants shivered less and many of them showed signs that they were actually very comfortable at this temperature. Among the tangible benefits that Pallubinsky and her team were able to determine were reduced blood pressure, lower cholesterol and boosts to energy and mood, with some participants seemingly getting a dopamine hit from the experience.
Being in a colder room could help people with Type 2 diabetes
Hannah Pallubinksy’s team also measured the effect that spending time in a colder room had on glucose metabolism – the removal of sugar from the blood and its subsequent processing – in people with Type 2 diabetes.
After the 10-day acclimatisation to the cold, participants were on average around 40% better at controlling their blood glucose levels. This is because one of the changes in the body as temperature drops is the increased production of a protein called glucose transporter 4 (or GLUT4) in muscle cells. GLUT4 helps make the removal of sugar from the bloodstream more efficient.
The cold changes your fat metabolism too
Another result of the Maastricht cold acclimatisation studies was a change in fat metabolism – namely the production of brown adipose tissue, or brown fat. Packed full of energy factories called mitochondria, which have a brown-ish colour when viewed under a microscope, brown fat cells burn sugar and other fuels to release energy in the form of heat. Brown fat is located along the spinal cord, under the clavicle bone and in the armpits – all important structures which need to be kept warm in cold conditions.
As Michael points out, the presence of brown fat in children has been long established but it’s only more recently that we have discovered that adults can make it too. “It's thought it can help reduce cholesterol, combat obesity and even limit the growth of some cancers,” he adds.
Not everyone will thrive in a colder room
With the continuing cost of living crisis and the potential health benefits, there are clearly incentives for turning down your thermostat, even if you start by doing it for just a few hours a day.
However, there are various groups of people who need to be cautious about making a change to household temperature, including older people and the very young, who tend to be vulnerable to the cold, and, in particular, those with heart problems or those at risk of a stroke. Anyone in vulnerable groups such as these should seek medical advice before attempting to adapt to the cold.
Remember: some of us feel the cold significantly more than others
It goes without saying that whoever you live with needs to be consulted about any change to your thermostatic temperature! In Michael’s case this is his wife, Clare, who feels the cold more than Michael. As Hannah Pallubinsky explains though, this is far from some kind of stereotypical response; there is solid science behind these different reactions .
“On average,” she stresses, “men have more muscle mass. So when you have more muscle tissue, you produce more heat and this keeps you warmer, and this really explains why – again, on average – women feel colder more easily than men.”
A 2018 study also found that women can start to feel the cold nearly 4°C above the threshold for men. “This makes me a little more sympathetic to Clare,” reflects Michael, who says that they have “come to a reasonable middle ground” and he has promised “not to try and lower the temperature any further.”
