Exposure to the cold may stop and even undo demyelination caused by multiple sclerosis (MS), a new mouse-model study from the University of Geneva suggests.
Scientists induced an MS-like condition in mice and then exposed them to cold conditions. Ambient living temperature for a mouse is between 30 and 32 degrees Celsius. The mice in the study had their environment turned down to 10 degrees Celsius.
The scientists wanted to test a part of life history theory that suggests that a living organism uses its resources to grow and reproduce, but when exposed to an external threat in their environment, the resources are diverted to repelling the threat and diverting energy. Here, the threat was the cold.
When the temperature was lowered, not only did the mice divert their resources to keep their bodies warm enough, they took heat from the immune system. Researchers say that when this happened, the immune system stopped attacking their nervous systems, which improved their MS symptoms.
“After a few days, we observed a clear improvement in the clinical severity of the disease as well as in the extent of demyelination observed in the central nervous system,” said Doron Merkler, professor at the Department of Pathology and Immunology and the Centre for Inflammation Research at the UNIGE Faculty of Medicine, and co-corresponding author of the work. “The animals did not have any difficulty in maintaining their body temperature at a normal level, but, singularly, the symptoms of locomotor impairments dramatically decreased, from not being able to walk on their hind paws to only a slight paralysis of the tail.”
"The symptoms of locomotor impairments dramatically decreased"
Someone who has known for a long time that cold temperatures can be beneficial for people with MS is Lee Morgan who runs Cryozone Health in Shrewsbury, Shropshire (www.cryozonehealth.co.uk). “Cryotherapy has many benefits to help manage symptoms of MS, helping to reduce inflammation, fatigue and provide a natural pain relief without the use of medication,” he explains. Cryotherapy is cold therapy, is a technique where the body is exposed to extremely cold temperatures for several minutes. It can be helpful for many conditions and is often used for repairing muscles after sport.
“The treatment helps to balance the body of free radicals and antioxidants, and to reduce oxidative stress which can lead to chronic inflammation,” says Lee. “Whole-body cryotherapy has been shown to raise energy levels and improve mood, to provide a natural remedy for depression, anxiety and insomnia.”
Lee explains the biological processes that happen when you experience the extreme coldness of the treatment. “When you step into a cryotherapy chamber your body is shocked by the cold, creating a flight-or-flight response. As your body cools down, it goes through a process know as vascular constriction. This limits the blood flow to the outer extremities of the body. Your heart beats harder and your blood flows faster. The cold interrupts the pain receptors to numb nerve pain. While this process is going on, the blood is filtered by the cardiovascular system, oxygenated and filled with good enzymes and endorphins. When you step out of the cryo chamber and you start to warm up you then go through vascular dilation, where the fresh blood is delivered around the body leaving you feeling exhilarated.”
The study’s researchers said that their work could be relevant not only for neuroinflammation but other immune-mediated or infectious diseases, but that it’s worth noting cold exposure can increase susceptibility to some infections, and more investigation is needed.
Source: MS-UK 22 November 2021