Cancer treatments often target glucose uptake to impede tumor growth, primarily through pharmaceuticals, many of which exert considerable side effects. However, cold exposure is emerging as a potential alternative to these drug-based therapies. A recent study in mice found that cold exposure reduced tumor growth by 80 percent and increased survival rates twofold.
Researchers conducted a two-part study in mice and humans. First, they exposed mice with cancer to cold (4°C, 39°F) or thermoneutral (30°C, 86°F) temperatures for about three weeks. They found that the cold exposure activated the animals' brown fat, depleting the energy supply available to the tumors. The cold-exposed mice exhibited marked tumor growth inhibition and a nearly twofold increase in survival rates relative to the thermoneutral mice. Interestingly, when they fed the cold-exposed mice a high-glucose diet, the animals did not experience the same extent of tumor growth inhibition, suggesting that glucose scarcity was pivotal in suppressing cancer growth.
In the second part of the study, they exposed healthy people to cool temperatures (16°C, 61°F) for two to six hours per day for 14 days and found that the participants experienced brown fat activation similar to the mice. Then, they exposed a person with Hodgkin’s lymphoma to cool (22°C, 71°F) temperatures for seven days and found that the participant exhibited activated brown fat and their tumor showed diminished glucose consumption, suggesting the findings in mice translate to humans.
These findings suggest that cold exposure activates brown fat, reducing blood glucose and impeding tumor growth. Brown fat is a thermogenic (heat-producing) tissue. Studies in animals and humans suggest that brown fat can improve glucose and insulin sensitivity, increase fat oxidation, and protect against diet-induced obesity. Cold exposure increases brown fat volume and metabolism and drives glucose uptake. Learn more about cold exposure and its effects on brown fat in our overview article.