Killer Fat

article:
http://discovermagazine.com/2007/feb/visceral-fat/article

summary and response:
In his statement, "Visceral fat does seem to be truly evil," Philipp Scherer makes an important distinction between visceral and subcutanoues fat. Visceral obesity ("beer belly") refers to intrabdominal fat, below the muscle wall, packed around the internal organs. It feels hard to the touch from the fat pushing up against the muscles of the abdominal fat and is related to a vast number of diseases and disorders, most notably diabetes and cardiovascular disease. Subcutaneous fat, on the other hand, is soft and flabby. It appears outside the abdominal wall in the belly, and also in the thighs and buttocks. "Peripheral (subcutaneous) fat is, in reality, good fat," states Osama Hamdy. They are like "two separate organs," Hamdy continues. But what makes up these differences? At first, location was thought to be the main difference. Vicseral fat is right around the liver and small intestines, but there seems to be more to the difference than just that.
Until 1994, adipose was simply thought to store oil. While this is true, discoveries are being made indicating that fat is actually a very active tissue. It secretes everything from hormones to enzymes and lipids. Fat is "now considered to be an active, complex endocrine organ, like the pancreas," (Discover). Visceral fat is one of the most active kinds of fat, but the problems arise when the fat cells "mature and become lazy, large, and dysfunctional" (Hamdy), as in old or obese patients. However, the majority of the negative impacts of visceral obesity are most likey caused by a very slight inflammation resulting from the clean-up of ruptured fat cells. This inflammation, while very slight, over chronic exposure "can have a negative impact on cardivascular health and insulin sensativity," (Scherer).
Research is also being done into the genetic differences between the two types. When James Kirkland cultured subcutaneous and visceral fat, he noticed that they still had distinct, differnt charascteristcs after 40 population doublings. "They seemed to retain a memory of the fat depot they came from." In mice, Kahn noticed 200 different genes in the two types -- 12 of which control develpment.
The best ways to reduce viseral obesity are mostly obvious: lose weight, excercise. Avoid trans fat, but also reduce stress.
I found this article to be extremly fascinating, especially the statement that fat is considered to be an endocrine organ. The genetic connection between obesity and the location of fat is much stronger than I would have thought. The influence of stress on visceral fat was also somewhat surprising. The article gave an interesting example about sumo wrestlers. While they would seem to be ideal candidates for diabetes, heart problems, and viseral obesity, the opposite is the case. Presumably through hours of excersice they manage to maintain a low viseral fat level while, through heavy eating, they have massive amounts of subcutanoeus fat. So the amount of fat doesn't mattter nearly as much as the location. Women have the advantage here, until menopause at least. The effects of the differences between the fats is also clearly evident in lyposuction patients. Since lyposuction removes only subcutaneous fat, it has no positive effects on insuling sensitivity, and can actually make things worse.