Until recently, scientist believed that we lose our brown fat, or "baby fat," by the time we are adults. But recent findings show that brown fat does persist into adulthood, after all. It seems to be most concentrated in the neck and thorax in adults.
Mitochondrion-rich brown fat (brown adipose tissue) is more easily "burned off" than the white fat (white adipose tissue [WAT]) that predominates in adults. Brown tends to become activated when a person is cold, producing heat that tends to restore the setpoint body temperature.
Beyond that, there's good evidence that there may be ways to stimulate the storage of lipids at brown fat rather than white fat in adults . . . meaning that perhaps it could be lost more easily (when active) than if the lipids were stored in white fat.
This new information is useful when discussing tissues, body fat composition, and metabolism in your A&P course.
Want to know more? Check out these resources:
Identification and Importance of Brown Adipose Tissue in Adult HumansHere is a recent video (with plenty of good animations and medical images) from NBC Nightly News that does a great job of laying out the importance of the discovery.
Aaron Cypess, et al.
New England Journal of Medicine Volume 360:1509-1517. Number 15. 9 April 2009
[FREE abstract of the original research article.]
Calorie-Burning Fat? Studies Say You Have It
New York Times 8 April 2009
[Nice summary of the new discovery; includes link to very nice graphics.]
No fad diet: 'Good fat' burns more calories
Associated Press story
MSNBC 8 April 2009
[Summary article that discusses the implications of the discovery]
[The video player embedded here may not appear in your news feed or emailed newsletter. Go to The A&P Professor blog to access the video viewer. Go to The A&P Professor website to learn how to embed the video in your PowerPoint or webpage . . . or simply link to it from your own email or webpage.]