BROWN FAT – WHITE FAT
As discussed in chapter 3, internal heat production, or thermogenesis, by the chemical dinitrophenol (DNP) is dangerous and potentially lethal. But scientists have known for some time that thermogenesis can also occur in a planned biological manner, as a mechanism for smaller mammals to avoid freezing to death from hypothermia.
Much of the research into thermogenesis has been performed on mice. Scientists have for many years known that mice can keep themselves warm in cold environments by converting theirfood energy directly into heat using their own mini-heaters. Mice have developed two different types of fat tissue, called brown and white adipose (fat) tissue -named because of their distinctive colours. The white fat tissue does what we would expect fat to do, it stores energy which can be accessed any time. The brown fat tissue however has an opposite role to play. It consumes energy and converts it directly into heat, the brown fat is the mice’s internal mini-heater.