Neurocysticercosis is the sciencey name for an infection of the human central nervous system by pork tapeworm larvae. The invasion of baby pork tapeworms in the brain "has become an increasingly important emerging infection in the United States," and is the #1 cause of epilepsy in the world. It is the most common parasitic disease of the human brain and used to be found throughout only the developing world (with the exception of Muslim countries, since less pork is consumed there). That all changed about 30 years ago, and now it's increasingly found throughout North America.
Besides seizures, the pork parasites may actually trigger brain tumors or cause an aneurism or psychiatric manifestation like depression. It can also result in dementia, but with deworming drugs this is often reversible. Only rarely do surgeons have to surgically remove the larvae.
I've talked about pork tapeworms before (see my videos Pork Tapeworms on the Brain, Avoiding Epilepsy Through Diet, and Not So Delusional Parasitosis). What's new is that we now know that they may present as chronic headaches--either migraines or so-called "tension-headaches"--even when the worms in our head are dead. What researchers think is happening is that as our body tries to chip away at the worms' calcified bodies, bits of them may be released into the rest of our brain causing inflammation that could be contributing to headaches.
This condition is rare even in endemic areas, but we can avoid getting infested with an adult tapeworm in the first place by cooking pork thoroughly. It's found in some parts of pig carcasses more than others (see the meat chart here), and the worms can be frozen to death no matter how infested the muscles are by storing pork (cut up into small pieces) for a month at subzero temperatures. Then to ensure the larvae are dead the meat is recommended to be cooked for more than two hours. That's one well-done pork chop!
The New England Journal of Medicine recently featured a case of some guy who must have had thousands of pork tapeworm larvae wriggling through his muscles. In my video, Chronic Headaches and Pork Tapeworms, you can see an x-ray, showing the thousands of little white streaks in this man's body. Each white streak is a baby tapeworm. That's why you can get infected by pork, it gets in the muscles. So cannibals might want to cook for two hours too.
Not all parasites are associated with meat, though. An anxious but healthy 32-year-old male physician presented to the family medicine clinic with a sample of suspected parasites from his stools, which had been retrieved from the toilet that same day. They looked to be about an inch long. He had previously traveled to India, had Chinese food the night before--who knows what he had. Maybe it was hookworms? The sample was sent to the microbiology laboratory for analysis. Later that day, the microbiology physician called to report positive identification of Vigna radiata (previously known as Phaseolus aureus) in the stool sample. Or in common parlance, a bean sprout. They were bean sprouts!
"The patient was called and gently but firmly informed of the diagnosis. Given the nature of the identified specimen, the information was presented in a non-judgmental, respectful manner so as not to offend the sensibilities or sensitivities of the patient."
Their parting advice to fellow physicians in cases of this nature was as follows: "as comical as the findings might seem--try not to laugh!"
Other parasites in meat include toxoplasma (Brain Parasites in Meat), sarcosystis (USDA Parasite Game), and Anisakis (Allergenic Fish Worms). There can even be critters in some dairy products (Cheese Mites and Maggots). Eating Outside Our Kingdom describes a brain malady caused not by meat parasites, but by meat proteins themselves.
One of the nice things about eating plant-based is that plant parasites, like aphids, don't affect people. When is the last time you heard of someone coming down with a bad case of Dutch elm disease?
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-Michael Greger, M.D.
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Image Credit: ML Cohen / Flickr