An Ottawa researcher has found that a little shivering boosts levels of a cholesterol-lowering and cancer-fighting protein.
Pascal Imbault, a professor of human kinetics at the University of Ottawa, has found that a small group of men who were kept at a cool temperature for two hours showed increased levels of adiponectin in their blood. The protein is secreted by fat cells and is known to fight diabetes, cancer and atherosclerosis (hardening of the arteries) as well as reduce cholesterol levels.
In fact, drugs that boost adiponectin are prescribed for people with high cholesterol. Those have side effects and people need to take them for 15 weeks in order to get a 15 to 20 per cent increase in adiponectin levels, Imbault said.
On the other hand, when healthy volunteers were exposed to cold, Imbault found their adiponectin levels increased by 30 to 70 per cent.
"This is quicker, and this is a substantial increase compared to the drug," he told CBC News in an interview last week.
The results were published in the journal Metabolism last spring. The researchers are trying to find out whether the high adiponectin levels are maintained after the body's temperature returns to normal. If so, it could be used as a cholesterol-lowering therapy.
New use for cold suit
The researchers have been dressing volunteers up in a hooded "cold suit" that covers them from their head to their feet and wrists in order to keep them at a controlled, safe cold temperature. That allows them to stay cold for a long period. The inside of the Lycra suit is criss-crossed by small tubes that lie against the skin. Water of a specified temperature circulates through them from a water cooler.
The suit was originally designed to keep workers such as firefighters and bomb disposal experts cool under extreme heat.
Jane Yardley, a part-time human kinetics professor at the University of Ottawa, who has worn it, said it's uncomfortable, but not that bad compared with other things she has done.
"You're kind of tired at the end of it 'cause that's a lot of [involuntary] muscle contraction," she said. "You can't just sit there and just say 'OK, stop shivering.' Your body's doing what it needs to do."
Depending on the results of future experiments, the cold therapy developed in Imbault's lab could be used to help people with high cholesterol who can't exercise enough to benefit from it, such as those who are morbidly obese.