Scientists are discovering that abdominal fat acts like an organ and causes more health problems than fat deposits in other parts of the body.

"Central obesity is not good," said James Brownlee, professor of family medicine at the University of South Florida and director of the Pre-Diabetes Treatment Center. "Having a big gut is worse than having a big butt."

Abdominal fat creates problems by pumping out hormones and other substances that contribute to a condition known as insulin resistance, which is one of the worst scourges to afflict the aging body.

Think of insulin resistance as "diabetes lite." What happens is, your pancreas pumps out insulin, but the insulin is no longer as effective as it once was at stimulating your cells to absorb glucose for energy. As a result, levels of glucose in your blood start to rise - not high enough to classify you as a diabetic, but high enough to spur your pancreas to pump out even more insulin.

This creates two problems. First, insulin itself seems to stress body tissues, so there's not a lot of it circulating in your blood stream. In addition, the heightened demand for insulin might exhaust your pancreas, which will lose its ability to produce any insulin. (Then you'll need injections of insulin to keep your blood sugar under control.)

What does this have to do with abdominal fat?

Scientists have known for decades that people with too much abdominal fat are more prone to diabetes and heart disease. Only in recent years have they found the reason - abdominal fat produces at least 10 hormones that affect the body's metabolism.

"We know now that adipose (fat) tissue is much more complex than previously thought," wrote Alan Saltiel of the University of Michigan School of medicine in the August 2001 issue of Nature Medicine. "It operates as an endocrine organ that releases hormones." Fat cells, especially in the abdominal area, are far more than mere "cargo space."

The hormones produced by fat cells regulate appetite, energy production and other aspects of metabolism.

Leptin, for example, discovered in 1995, was the first hormone that scientists recognized as a product of fat cells. It produces a feeling of fullness and quells the desire to eat. When we haven't eaten for a while, our fat cells release triglycerides into the blood for energy and they block the effect of leptin, producing a feeling of hunger.

We gain weight when our fat cells become bloated and release triglycerides, causing us to feel hungry even when we have consumed plenty of calories. It's a vicious cycle - the more fat we accumulate, the more likely we are to overeat.

The same problem occurs with adiponectin, a recently discovered hormone also produced by fat cells. Adiponectin helps muscles burn fat and suppresses inflammation, which can damage the walls of our arteries. Paradoxically, when we gain weight and create more fat cells, they produce less adiponectin. The lower levels of adiponectin in the blood make the body more prone to high blood pressure, elevated glucose and cholesterol levels, and heart disease.

But won't liposuction remove excess abdominal fat?

It does, and you may look better, but according to a recent study in the New England Journal of Medicine, it won't improve your health very much.

To the surprise of scientists, and perhaps to the dismay of plastic surgeons, the study demonstrates "that losing fat by sucking it out does not give metabolic benefits," said the lead author of the study, Samuel Klein, director of the Center for Human Nutrition at the Washington University School of Medicine in St. Louis.

Liposuction removes only subcutaneous fat: that roll you feel between your fingers when you pinch your belly. It does nothing to remove the visceral fat that accumulates around the abdominal organs. It's those deeper deposits of fat that seem to cause the most serious problems.

How and why do they cause serious problems? "Fat cells release inflammatory cytokines and these cause plaque in the artery wall to become unstable," said Brownlee. "A recent article in Circulation showed that most people who have a heart attack don't have significant blockages. Close to 50 percent simply fall over dead."

The reason, he said, is that when plaque deposits in artery walls become inflamed, they can rupture. When that happens, a large blood clot may form at the site of the rupture, blocking blood flow. In extreme cases, the clump of plaque is actually released into the bloodstream, where it is likely to block the artery somewhere downstream.

The best way to reduce abdominal fat, then, is through diet and exercise, which will shrink the size of fat cells throughout the body, but especially in the abdomen. Once the fat cells return to normal size, the leptin they release will be more effective at suppressing your appetite, the amount of beneficial adiponectin in your body will increase and the other substances produced by fat cells are likely to return to optimal levels.

Tom Valeo is a freelancer who writes about medical and health issues. Write to him c/o Seniority, the St. Petersburg Times, P.O. Box 1121, St. Petersburg, Fl 33731 or e-mail features@sptimes.com

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