There is a nasty Public Service Announcement (PSA) campaign going on in Australia, featuring very graphic pictures of visceral (belly) fat, surrounding organs. Belly fat has been labeled as the worst kind of body fat you can have; and the Australian PSA calls it “toxic fat”.
Fatness, in general, is a tradeoff – there are costs and benefits. A PSA that demonizes a natural party of the body like belly fat is not helpful.
Mostly, belly fat is part of an organ called the omentum.
According to Mednet.com:
Definition of Omentum: A sheet of fat that is covered by peritoneum. The greater omentum is attached to the bottom edge of the stomach and hangs down in front of the intestines. Its other edge is attached to the transverse colon. The lesser omentum is attached to the top edge of the stomach and extends to the undersurface of the liver.
And RealAge.com says:
The omentum is a fatty layer of tissue located inside the belly, where it hangs underneath the muscles in your stomach (which is why some men with beer guts have hard-as-a-keg bellies — their fat is under the muscle). You may hear people on the street refer to it not only as a beer gut but also as belly fat, love handles, a beach-ball belly, or a spare tire. Doctors refer to it as visceral fat or intra-abdominal adiposity (IAA).
The omentum is very good at catching and storing fat, and because the fat is close to your organs, it’s the best source of energy for those organs. But the omentum does a whole lot more than store fat and, the fat cells in the omentum do a lot more than provide energy:
- It is rich in blood vessels and can stimulate growth of new blood vessels into whatever tissue it is surgically placed next to (including the brain and spinal cord).
- It is rich in lymphatic vessels and tissue that are critical in removing metabolic waste and excess fluid, destroying toxic substances, and fighting disease.
- Areas called “milky spots” located in the omentum can generate specialized immune cells that facilitate healing.
- It is a rich source of material that enhances tissue growth, including agents involved in inflammatory and immune processes.
- There is evidence that omental tissue contains stem cells.
As Wikipedia points out, the greater omentum can often be found wrapped around areas of infection and trauma. (Whaliam pictures this as sort of an internal hug from the omentum to make the injured area get better.) Although the omentum has been used for many years for its ability to seek and contain the site of injury, little is understood about how it works, especially regarding its anti-inflammatory and wound healing properties.
A new study looked at two subsets of omentum cells: immunomodulatory myeloid derived suppressor cells, and omnipotent stem cells that are indistinguishable from mesenchymal stem cells. I know, that’s a mouthful. Basically, they looked at two types of cells – cells that are like bone marrow or spinal cord tissue (myeloid) and cells that act like stem cells (adipose tissue has already been found to be a useful source for creating stem cells).
It was found that that once activated (by the presence of foreign bodies) the omentum grows and produces non-fat stromal cells (connective tissue) that are a rich source of growth factors, and express both adult and embryonic stem cell markers. These cells can become bone, fat or cartilage tissue, and this flexibility may be one reason why the omentum is so good at promoting tissue regeneration for all kinds of injuries. Cells like these were originally identified from bone marrow but cells with similar characteristics have been isolated from other tissues such as adipose (fat) tissue.
Activated omentum cells also include factors with immunosuppressive functions that provide a regenerative environment for injured tissues, limiting the area of damage and aiding a regenerative response. In other words, the omentum helps new healthy tissue form and helps keep that new tissue “safe” until healing has taken place!
In the future, cells from the omentum may be valuable for use in supporting tissue healing and regeneration in a variety of inflammatory disorders.
Who knew my belly fat was so talented?