Tapeworms and the Search for a Slimmer Waist








Jolene Kokroko


Feb 27, 2010

HumBio 153

ParaSites Paper

As more and more Americans struggle with control over their weight, the search for effective weight loss products and gimmicks continues to rise. Among the diet supplements, weight loss self-help books, and wasted gym memberships, people are turning towards science for the answer to their problems. With this trend, people have asked whether or not tapeworms, a type of gastrointestinal parasite, could prove effective in natural weight loss. Many people believe that historically tapeworms were used for weight loss, but no substantial evidence exists to confirm whether or not this practice was effective or even widespread. This paper explores historical and scientific evidence in order to evaluate the claim that tapeworms are an effective method of weight loss. First, the paper outlines the most common species of tapeworm, morphology, natural transmission, lifecycle, clinical symptoms and risks, as well as recommended treatment and management. Second, this paper profiles historic evidence of tapeworm use for weight loss. Next, the paper examines present claims of an online product “The Tapeworm Diet.” Lastly, the evidence from five different scientific studies will provide evidence some for and against the use of tapeworms as weight loss aids. From this substantial research, it is clear that the use of tapeworms for weight loss is neither effective nor recommended and any benefits that might arise coincidently are far out weighted by the negative risks for hosting a tapeworm in your intestines.

            The tapeworm is thought to aid in weight loss because of its morphology and lifecycle. Tapeworms are part of the Cestoda class of Platyhelminth flatworms that live in human hosts’ gastrointestinal tracts. The Center for Disease Control notes that tapeworms are distributed worldwide but mainly in poorer communities. The most common tapeworms are Taenia solium, Taenia saginatum, Taenia asiatica, Diphyllobothrium, Hymenolepis, Dipylidium caninum, Echinococcus, Spirometra, Taenia multiceps (Irizarry, 1994: Medscape). Tapeworms have no intestinal tract of their own and instead rely on the host for nourishment. Tapeworms do this by attaching their head, known as the scolex, to the mucosa of the intestinal tract, using suckers and hooks as anchors, and absorb nutrients and proteins directly from the intestinal lining. The scolex begins to proliferate and will become reproductively mature in 5 to 12 weeks (Song et. al., 2004). Their long bodies consist of segments called proglottids which are actually the male and female gonads that are broken off periodically and exit the body during reproduction.

 Once these proglottids containing the eggs have passed to the outside environment through the feces, the outer layer dissolves leaving just eggs. These eggs can be ingested by intermediate hosts. The eggs then hatch in the acidic environment of the stomach leaving behind larvae that then travel through tissues and blood to become cysts in the host tissue. The primary host, namely humans, will ingest the cysts embedded in the flesh of the intermediate host (Irizarry, 1994: Medscape). More commonly, infected humans are the primary host, meaning the tapeworm is confined to the intestinal tract, from eating meat that contained a cyst. In other cases, humans can act as intermediate hosts infected by eating the eggs that passed through another primary host. This means that the tapeworm larvae can burrow into the intestines and travel throughout the host’s body and organs. The adult tapeworm can last up to 25 years in a primary host (Song et. al., 2004).

Within humans, the tapeworm causes a wide range of presentations and symptoms which are highly dependent on each host. The only guaranteed typical symptom from hosting a tapeworm is the passage of proglottids through the feces; rarely appendicitis occurs due to proglottids migration (CDC, 2010). Lisandro Irizarry, a doctor of Cornell School of Medicine and Medscape reporter, stated that the proglottids have the muscle capacity to migrate out of the rectum which may also causes itching (Irizarry, 1994: Medscape). More common symptoms but dependent on each host are abdominal pain, change in appetite, diarrhea, nausea, infection, anemia, fever, eosinophilia, and weight loss (Song et. al., 2004). Dr. Irizarry also noted that malnutrition often arises from a specific species’, Diphyllobothrium, absorption of vitamin B12.

Additionally, ascites, a response to parasitic infection causing the build up of fluid in the abdominal cavity resulting in a swollen and extended belly, often occurs (Song et al., 2004). This symptom is counter to the weight loss desired. Lastly, and perhaps most important is the danger of cysticercosis which occurs when a human host digests a tapeworm egg instead of the cyst. When this occurs, the tapeworm larvae burrow into the bloodstream and can end up encysted anywhere in the body, particularly in the brain, eyes, and lungs (Song et al., 2004). In rare cases, neurocysticercosis occurs in which the cyst forms in the central nervous system or skeletal muscles causing seizure, epilepsy, major brain damage, and dementia (Irizarry, 1994: Medscape). However, using tapeworms for weight loss requires ingesting a cyst form of the tapeworm, not the egg. Cysticercosis would only occur if given the wrong form of the tapeworm which is a risk tapeworm dieters would have to take. The Center for Disease Control recommends that tapeworms be killed, not tolerated, using Praziquantel and then passed through the feces (CDC, 2010). Tapeworms can be diagnosed by microscopy of the eggs, antibody detection, and morphological comparisons of the actual worm (CDC, 2010).

Historically, the prevalence of tapeworm self-infection for weight loss was not widespread. The theory behind the claim is that the tapeworm will absorb nutrients and calories so that a person can eat anything, enjoy the taste of food and watch extra pounds melt away. Barbara Mikkleson, an investigator from Rumor Has It, reports that there is some evidence that pills were sold in the U.S. from 1900 to 1920. She states “overall, it is undetermined whether or not the products were sold or if they even had tapeworms in them” (Mikkleson, 2006). Some people may have heard of opera singer Maria Callas whom many believed had lost 60 pounds due to a tapeworm that inhabited her gut. Though no evidence exists to confirm this causation, reporter Ed Grabianowski, from How Stuff Works, believes that Callas’ weight loss and her tapeworm was coincidental at best (1998). Author Ronald L. Baker, who wrote Hoosier Folk Legends, stated in his book of myths and legends

A few years ago there was a company who put out sure-fire diet pills, guaranteed to lose weight in no time. People began to take these pills, and in no time the people were losing weight. After a few weeks these people began to lose too much weight. So the government investigated. They opened the pills and found the head of a tapeworm. Tapeworms are hard to get rid of. They had the person starve himself for days. Then they set a bowl of hot milk in front of the person. He had to keep his mouth open. After a while the tapeworm began to come up his throat ‘cause he smelled the milk. They kept moving the bowl further away until the tapeworm was completely out (Baker, 1982:226)


Baker’s description of this legend reveals that there was little scientific evidence to suggest one way or another that tapeworms were an effective weight loss product. The rumors that continued through the 20th century were based on the theory of commensalisms. In an interview from 2009 entitled “Fear no Worm,” Amy Maxmen asks David Artis of the University of Pennsylvania to explain this theory and whether or not there is any correlation between tapeworms and weight loss. Artis explains that helminth worms are sometimes used to counter the effects of immune-hyper-responsiveness and inflammatory bowel disorder that are thought to arise from having too little exposure to bacteria and other agents in the environment essentially weakening the immune system (2009:262). However, he in discussing tapeworms he states “I think that in Victorian times that was quite popular. As I understand it, however, tapeworms are not an effective way to control weight gain” (2009:263). Historically, there is little evidence that the use of tapeworms for weight less was not widespread.

            In today’s culture of instant gratification with minimal input, the tapeworm diet has resurfaced as a way to lose weight fast. “The Tapeworm Diet: all natural weight loss,” an internet product which claims to help people loose weight, is no exception. The “Tapeworm Diet” is based on the idea that worms and humans coexisted as a means to keep the human immune system in check. Because it is not FDA approved, customers have to leave the country and obtain and ingest the tapeworms in Mexico in order to participate in this diet. Their website, www.tapewormdiet.net, states that Taenia saginata has the lowest side effects and risks which is why this is the worm of choice. The risks outlined on the website are the same that other medical professionals and the CDC have also outlined, including loss of appetite or feeling of fullness, increased appetite, abdominal pain, weakness, headache, nausea, constipation, diarrhea, vomiting and spontaneous emergence of proglottids from the anal sphincter along with blockage of the common bile duct, pancreatic duct of appendix due to proglottids migration which is life threatening (www.tapewormdiet.net). Loss of appetite, one of the symptoms outlined on the website, could be a confounding factor in any decrease in weight while the website attributes it to the tapeworm absorbing your extra nutrients.

Despite these risks, “the Tapeworm Diet” claims that you can and will loose about 1 to 2 pounds per week. A link titled “Is this real?” leads readers to the webpage of a Japanese man, whose experiment is unaffiliated with any university, who has supposedly lost weight by the same methods. This is their only testimony to the effectiveness of their product. Weight loss, if it occurs at all, appears to also be due to encouragement of a good diet and exercise. The website states keep in mind the net loss of calories will be modest even in the most responsive of individuals, and that the worm cannot improve a bad diet, address overeating or compensate for a lack of physical exercise” suggesting that any weight loss could actually be due to increased exercise and attention to diet not solely the tapeworms (www.tapewormdiet.net).

Nevertheless, the website claims that for only $2,000, anyone can achieve weight loss. “The Tapeworm Diet” claims that the beef tapeworm, Taenia saginata,,

secretes proteins that hijack the human intestine by either speeding it up or slow it down depending upon the location of the secreted protein in the digestive tract. The net effect is to make us less efficient at digesting our food…the tapeworm manipulates the speed of the digestive process so that it optimizes its interface with the nutrients the worm needs to develop (www.tapewormdiet.net)


As a whole, “The Tapeworm Diet” consists of harvesting tapeworm cysts from cattle, which means killing the cattle to retrieve the cysts from the meat, treating the cysts with UV radiation and other antibiotic solutions, ingesting the cysts, watching the weight melt away, taking Praziquantel after 3 months to kill the tapeworm and give your body a rest, then repeating the cycle (www.tapewormdiet.net). However, numerous scientific studies published in scientific journals present evidence that this theory is false. This paper will now examine those studies.

As stated before, using tapeworms as a weight loss method is based on the commensalisms between parasites and hosts. Researchers Crompton and Nesheim, in their 1982 paper “Nutritional Science and Parasitology: A Case for Collaboration,” question whether or not with the right nutritional intake, the harmful side effects of helminthes still exist. Their paper outlines two different manners in which hosts and gastrointestinal parasites interact relevant to this paper: 1) “all hosts provide nutrients and energy for their parasites, either by ingesting nutrients or at the expense of their own tissues, fluids, or cells” and 2) “host food intake, digestion, absorption, metabolism, and general utilization of nutrients are frequently disturbed by a parasitic infection” (Crompton and Nesheim, 1982). Their study of rats and tapeworms suggested that “although parasites deprive their hosts of nutrients, if the host is adequately nourished, the effects have been considered to be insignificant. However, if the host is malnourished, any removal of nutrients by the parasite must result in a significant loss” (Crompton and Nesheim, 1982). Here, the authors are suggesting that a commensalism can occur when hosts are adequately nourished. The question then becomes, however, what does being “adequately nourished” entail and would that counteract any losses in weight that do occur. Unfortunately, little research has been done on this topic in humans for various health reasons. Crompton and Nesheim’s study with laboratory rats did find that rats infected with parasites on low protein diets died or lost weight at a greater rate, but the uninfected rats lost significantly more weight (1982). The authors state that the “implication is that, in some as yet unexplained manner, the uninfected pair-fed rats used their nutrients more effectively than the infected hosts” (Crompton and Nesheim, 1982). In other words, the weight loss from being on a low protein diet was more substantial than being on a low protein diet with a tapeworm where malnutrition and death was the end result.

Though weight loss is a known side effect of hosting a tapeworm, little evidence shows that this weight loss is due directly to the tapeworm’s absorption of food and nutrients in the host. Additionally, the risks and potential complications do not appear to be outweighed by the slight reduction in weight that sometimes occurs. Ed Grabianowski points out that tapeworms cannot absorb the amount of calories that humans consume and when placed on restrictive diets, people with tapeworms often become malnourished (1998). Researcher Clark Read, author of “The ‘Crowding Effect’ in Tapeworm infections,” states that “the amount of carbohydrate ingested by the host is hundreds of times the greatest requirement of an excessive number of large worms” and “limiting the food of her experimental rats to one-half or one-third the normal intake had no apparent effect on the egg production of H. diminuta, whereas crowding caused an inhibition of reproduction” (2000). This is important because it shows that one tapeworm would not have a great effect on the amount of food not absorbed by the human host. This research also suggests that having access to the mucosal lining is how tapeworms grow and reproduce meaning their main food and nourishment comes directly from the intestinal lumen and not from food simply deposited in the stomach. In his paper, “Studies on the nutrition of tapeworms,” C. Chandler repeated the above findings. He found that “the worms are totally independent of protein in the diet of the host… therefore, that the worms absorb nitrogenous substances directly from the mucous membranes” (Chandler, 1943). Based on this research, the theory that tapeworms will absorb all the food that a host consumes is simply not possible.

Other studies suggest that the side effects of tapeworm infection disturb host’s lives and have negative health outcomes. For example, in Barnett et al.’s paper “Tapeworm infestation: a cause of iron deficiency anemia shown by capsule endoscopy,” doctors found that ulcers and anemia were caused by a tapeworm (2007). Their studied profiled a 14 year old boy with recurrent anemia, a normal diet but no known parasite found. After the tapeworm was removed, the child’s blood results returned to normal (Barnett et al., 2007). Similarly, Song et al. found tapeworm symptoms that arguably counteract the little weight loss that would occur. In “Unusual manifestations of Taenia solium infestation,” Song et al. found that a 30 year old woman experienced dyspnea, mild abdominal extension, heptic cysts, and after medication her blood eosinophil dropped from 47% to 5% (2007). Then, for a 67 year old man who experienced a 3 year history of diarrhea with episodes of diarrhea three to five times every day, weight loss, and indigestion once given medicine to eliminate the tapeworm his symptoms disappeared (Song et al., 2007). His overall weight loss was 10kg (about 22lbs) but there is no evidence that this loss was due to the tapeworm absorbing nutrients and extra calories rather than the symptoms of diarrhea and loss of appetite, a very unhealthy way to loose weight.

Though the use of tapeworms for weight loss seems promising, there is not enough evidence available to suggest that this type of weight loss is sustainable, healthy, and actually effective. Historically, this practice was not widespread and with good reason. The majority of the evidence currently available suggests that ingesting tapeworms for weight loss is ineffective and even harmful to the host. Having a tapeworm in your body comes with substantial risks that are shown to outweigh the potential weight loss. There is evidence that hosts do lose some weight while having a tapeworm inside of them; however, this is not known to be due to the absorption of calories and nutrients alone, but from other side effects that occur in conjunction with hosting a tapeworm. People seeking to lose weight would be better off cutting calories and exercising than risking hosting a tapeworm in their intestines.



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Read, Clark. “The ‘Crowding Effect’ in Tapeworm Infections.” Journal of Parasitology, Vol. 86, No. 2:206-208 Apr. 2000.


Song, Eun Kee; Kim, In Hee; Lee, Seung Ok. “Unusual manifestations of Taenia solium infestation.” Journal of Gastroenterology 2004:No. 39:288-291