For a long time, fat was just thought of as “there”—perhaps unsightly and bothersome, but not active in its own right. We now know that excess weight and fat stores can lead to bone and joint, cardiovascular, pulmonary, cellular and blood sugar unhealth.
But that’s not all excess fat does. More recent findings indicate that fat is also busy making chemicals that cause inflammation, which is believed to be an underlying key player in unhealth.
In the past, weight issues were thought to be solely results of the metabolic system, while inflammation was seen as a separate function of the immune system. What we have grown to realize, however, is that the metabolic and immune systems are bound together.
We see this bond when people are undernourished or in starvation mode. Metabolism slows down to conserve energy; in turn, the immune system slows down and isn’t as capable of fighting off invaders. This side of the metabolic-immune system coin—starvation—is still present in some countries in our world.
Our robust nation, however, encounters the flipside of the coin. A full two-thirds of Americans are overweight, and one of the results of the metabolic-immune relationship for the overweight is excess inflammation.
Here’s why: Fat cells increase in size—not number—and with increased fat, these fat cells produce something called cytokines. Cytokines release proteins that regulate immunity and inflammation, but as fat cells get larger, their cytokine production increases, too. This leads to more inflammation.
Additionally, other cells called macrophages produce cytokines—especially as fat increases. Kept in check, macrophages serve us well. They are our immune system’s first line of defense, guarding against infection and ridding the body of dead cells. In overweight people, however, macrophages proliferate, go into overdrive and produce inflammation-promoting cytokines.
Why the proliferation of macrophages? Simply put, they are doing their job. As fat cells become larger, some will burst, leak or die—creating cellular debris that the macrophages clean up. In the clean up process, however, inflammation levels increase.
It seems that belly fat—the kind that’s packed around the abdominal organs—is the worst culprit. In 2007, scientists from Washington University School of Medicine in St. Louis provided some of the first evidence of a link between abdominal fat and systemic inflammation. They reported in the journal Diabetes that visceral fat is a likely contributor to producing inflammatory cytokines that can lead to systemic inflammation and blood sugar imbalance.
The good news, however, is that weight loss through diet and exercise can offer improvement. People who have lost weight through these lifestyle changes have also reduced their inflammation-producing cytokines.
That’s yet another reason to get rid of that jelly belly.