A Fat-Burning
Powerhouse the ‘Brown fat’
Some very interesting and important clinical
studies[4,5] several years ago showed that brown fat is actually
present in some adults. What does brown fat do? Brown fat is brown because it
contains mitochondria; those are the energy-producing organelles in each and
every cell of our body. But, brown fat has a lot of mitochondria that can
generate heat. Uncoupled, the mitochondria burn fat and glucose, and that
generates heat to keep us warm in the cold. Until just a few years ago, the
only reason we thought we had brown fat was to keep warm.
It turns out that brown fat is a lot more
interesting. It can consume a lot of glucose when it's stimulated, either by
cold or by hormones. We will talk about those hormones in a few minutes. But
brown fat also takes up fat and burns it in a way that allows us to blow off
the extra calories if we eat too much. This is important for patients with
diabetes, because it is a real "glucose sink." It can suck up a lot
of glucose from the blood. Several scientists, some of whose data[1] have been presented here at the ADA
A Fat-Burning
Powerhouse
Brown fat is found between the scapulae in the
back as well as in the supraclavicular area, around the heart, and around the
kidneys. Those fat deposits are very important for metabolism. As a person
develops obesity or diabetes, these brown fat depositions seem to shrink in
size and reduce their activity. A lot of basic science interest has arisen
about how we might be able to flip the switch and turn these brown fat cells on
to burn more brown fat and help them develop more normally.
Without going into too much detail, hormones
that are secreted from the heart and other hormones appear to be able to
activate brown fat to make it grow and become activated and produce more heat,
and to take up that glucose and fat as well. Although hormones are important,
the primary stimulus for the activation of brown fat is the sympathetic nerve
terminals.
There is also some thought that the
beta-blockers used to treat hypertension might actually be turning brown fat
off. That may be one of the reasons that beta-blockers increase body weight.
That is the story about brown fat.
Even more interesting is the idea that there
might be beige or bright fat. What is that? It turns out that there is an
intermediate cell type in white fat that doesn't just store fat, but also has
the capacity to burn it. That is another hot topic here at that ADA
That is some of the emerging science. I hope you have enjoyed this discussion about brown fat -- the good
fat, the new kind of fat that we are trying to turn on.
drshawnie
918.249.1535
