Pathways for brown adipose tissue activation in humans

The human body has two types of fat: white fat (for energy storage) and brown fat. Brown fat is activated by cold temperatures and helps the body maintain a healthy temperature by generating heat. It is known as 'good' fat, as it helps the body burn fat stores. Previous studies have found increased brown fat activity in mice with an overactive thyroid gland, which prompted this PhD study to focus on patients with thyroid cancer. After having their thyroid gland removed, these patients were treated with thyroid hormones. Hormone levels returned to normal within three to four months. The effects of the thyroid hormone on brown fat activity were studied during the treatment process and it was discovered that this hormone did indeed increase the quantity of active brown fat.

The study also examined bile acids. Studies in humans have found that both energy consumption and brown fat activity increase with the administration of bile acid tablets.