Will eating tapeworms help you lose weight?
In her book Seabiscuit, Laura Hillenbrand states that in the 1930s racehorse jockeys trying to lose weight would swallow a capsule containing a tapeworm egg. The worms would then mature in the jockeys' stomachs and eat whatever food was dropped their way. I'm sure you've heard this same story in connection with the great opera singer Maria Callas and other celebrities with a weight problem. When I expressed doubt, I was told I'm full of worms because Hillenbrand wouldn't have included this in her book if it weren't true. Help me worm my way out of this.
I swear, every time you think you've heard the absolute stupidest thing imaginable, something else comes along to make you realize you've barely scratched the surface. It's one thing to accidentally ingest a tapeworm, as one Chicago diner recently claimed to have done, but surely no one would do so on purpose, right? On investigation, however, we discover that not only is Hillenbrand's story plausible, somebody's hawking a tapeworm diet plan on the Web even now.
Let's talk tapeworms. Ideally adapted for living inside other animals, most species of tapeworm have a similar life cycle. Once within its host a tapeworm continuously releases eggs (or pregnant segments of its body), which are passed out with the feces and then ingested by a subsequent animal — a cow, say, via contaminated feed. Larvae hatch from these eggs and infect the tissues of their new host, hiding inside a protective cyst, where they wait until the animal dies and its flesh is eaten by yet another animal, e.g., us. When we digest the infected meat the outer layer of the cyst dissolves, freeing the worm, which attaches itself to our intestines, where it starts laying eggs and the process starts all over. The great circle of life — ain't it beautiful?
We'll get to the practical implications of tapeworm dieting in a moment. First a more pressing question: Did anybody honest to God think this would work? Answer: Evidently. A few seconds with Google turns up an authentic-looking advertisement for "sanitized tapeworms" ("friends for a fair form") that appears to date from the turn of the last century. A hoax? Maybe, but it convinced at least one medical expert, endocrinologist Zachary Bloomgarden, who in a 2000 article in Diabetes Care wrote, "Approaches to decreasing nutrient absorption date from the early 1900s, when diet treatment with 'sanitized tapeworms' was widely advertised."
So let's assume the ad is legit, in the sense that this product was actually for sale a century ago. Did whatever they were selling really contain live tapeworms (or tapeworm cysts or eggs or heads)? Beats me, but I'm betting significant tapeworm consumption was low — else the screaming would still be reverberating today. Fact is, having a tapeworm inside you is beyond gross. An adult tapeworm can grow up to 50 feet long and live up to 20 years. Tapeworm eggs are even worse, as the larvae that emerge from them are prone to burrow out of your intestines and find homes elsewhere in your body. For example, the pork tapeworm can cause neurocysticercosis, in which the larvae migrate through the stomach or intestinal lining and up into your brain. There they form destructive cysts, triggering immune responses that can lead to epileptic seizures or worse. The cysts formed by sheep tapeworm larvae may reach the size of grapefruit; they can rupture blood vessels when they break, resulting in shock and death.
Death, schmeath, you say: will I lose weight? Probably, but there are some real downsides to tangling with even the relatively benign beef tapeworm, including nausea, abdominal pain, diarrhea, and a general feeling of illness. There's also the risk of malnutrition. The fish tapeworm, for instance, can steal vitamin B-12 from its host, leading to anemia. If you ask me, the possibility of having a worm emerge unexpectedly from a bodily orifice is also a significant disincentive. Plus you might get ascites, a fluid buildup causing your gut to swell, which is hardly the desired effect.
But come on, if people will try stomach stapling, they'll try anything. It's quite possible jockeys in Seabiscuit's day at least talked about swallowing tapeworms to lose weight, presumably after having struck out with all-egg diets, forced vomiting, running in the heat wearing a rubber suit, and gut-wrenching laxatives that probably put the rider's life at risk as much as any tapeworm. Whether any actual tapeworms got eaten, and if so with what result, are matters on which I'm content to remain agnostic. As for celebrities, I'm not seeing many confirmed cases. You mentioned opera diva Maria Callas, rumored to have taken tapeworms after she abruptly lost a lot of weight in midcareer. Though she was indeed diagnosed with at least one tapeworm infection, biographer Anne Edwards (Maria Callas: An Intimate Biography, 2001) says the likely cause was her love of raw meat.