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Ghrelin Theory

I wanted to share something that I read in August from Tufts University's Health & Nutrition Letter" for August 2002. "Newly Discovered Hormone Opens Up More Possibilities for Obesity Treatment" "Researchers have discovered a new explanation for why it is so hard for many dieters to keep off lost pounds. A hormone that increases hunger tends to rise in the bloodstream when someone loses a significant amount of weight. The hormone is called ghrelin (GHREH-lin), and a team of Seattle investigators measured its influence when they studied 13 obese adults who went on a low-calorie diet for 6 months. After the diet, during which the subjects lost an average of 17 percent of their body weight, ghrelin levels rose substantially. Levels of the hormone always rise before mealtime, when hunger is peaking. But the dieters' ghrelin levels were significantly higher at all points of the day than prior to the weight loss. "This certainly suggests that a rise in ghrelin may be one way in which your body fights against weight loss," says lead researcher David E. Cummings, MD, of the University of Washington. Stomach function involved

In a seemingly contradictory finding, the Seattle researchers found that people who lost even more substantial amounts of weight after undergoing gastric bypass surgery had consistently LOW levels of ghrelin. What's more, their ghrelin levels did not rise and fall with meals. Why? Ghrelin is produced mostly by the stomach. If much of the stomach is "shut off" with gastric bypass surgery, which drastically reduces its capacity, it cannot produce the same amount of ghrelin that it's naturally programmed to make. Perhaps, the researchers hypothesize, that's why people who lose weight with gastric bypass tend to be relatively successful at keeping off their lost weight. The usual thinking is that it's solely because their stomachs can't hold as much (even though it's possible to put pounds back on by eating small amounts of calorie-dense foods throughout the day). But, presumably because of the consistently low ghrelin levels, they're simply not as hungry anymore. Indeed, those who have had gastric bypasses generally have been shown to feel less hungry after the operation. The trick for pharmaceutical researchers, if further studies validate the findings, would be to learn how to shut off ghrelin production--or block its effects--via medications rather than by gastric bypass."

Pretty interesting huh? I can just visualize these little ghrelin-creatures running around in my stomach yelling "hungry hungry hungry" :)

vmossman2@attbi.com
Last updated on 10/18/02