The Crab Shell Game

Eating crabs is a tough business. First you have to tear the creatures limb from limb for the sake of a few tasty morsels. Then there s the mess you make by dipping those bits of liberated flesh into butter. And what are you left with A pile of guilt, a heap of mangled, empty crab carcasses, and some interesting chemistry. 

The exoskeleton of the crab and other crustaceans is primarily composed of a substance called chitin. This is a giant molecule made up of fundamental units of N-acetyglucosamine strung together like links in a chain. Chitin is abundantly available, thanks to a crab and lobster industry dedicated to making it easier for us to consume their products by removing the 

The hucksters provided a demo. Viewers watched in amazement as a demonstrator sprinkled chitosan onto a pool of oil that was floating in a glass of water. The oil thickened and sank to the bottom. You didn t have to stretch your imagination too far to envision the same kind of magic taking place in your gut. 

Take some chitosan, stuff yourself with cake, and the fat will vanish from your body. Hey — not so fast  

While that demonstration is an attention-grabber, it isn t realistic. You can t stuff yourself full of fat and expect chitosan to save you from dietary damnation. There s a limit to the amount of chitosan that the body can handle comfortably. One can easily handle a few grams a day, and the stuff will prevent the absorption of some ten to twenty grams of fat, but that would hardly make a dimple in the fat content of the cornucopia of rich foods the hucksters insist we can consume without guilt. Clearly, chitosan is no miracle. There is no fat-free lunch. But chitosan is not a total dietary dud, either. 

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