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Parasite cleanses are ‘modern snake oil.’ Experts explain why.

Steer clear of herbal treatments for parasites. (iStock)

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You don’t need to spend much time hobnobbing in wellness circles — on social media or in real life — before parasite cleanses come up. Long before they started trending on TikTok, I succumbed to doing a parasite cleanse because a doctor suggested it in her book about autoimmune disorders. According to the book, you could have intestinal parasites if you experience three or more of these:

  • Constipation, diarrhea or gas.
  • International travel.
  • “Traveler’s diarrhea” while outside the country.
  • What you believed was food poisoning, and your digestion has not been the same since.
  • Trouble falling asleep and waking up multiple times during the night.
  • Skin issues, such as eczema, psoriasis, hives, rosacea or an unexplained rash.
  • Teeth grinding during sleep.
  • Muscle or joint pain or aching.
  • Feeling exhausted, depressed or apathetic almost all the time.
  • Never feeling satisfied after meals.
  • Iron-deficiency anemia.
  • Diagnosed irritable bowel syndrome, ulcerative colitis or Crohn’s disease.

Imagine my dismay as I checked off each one of these ailments. The cleanse involved taking herbal supplements that consisted of cloves, black walnut and wormwood — the dosage of which was literally fistfuls of gelatin capsules each day. And since I struggle to swallow even the tiniest pills, I quickly gave up and opted for a stool test at my doctor’s office. Some parasites can be visible under a microscope, and DNA tests can identify those that might not be so visible.

I didn’t have any intestinal parasites, which are scientifically called “helminths” (the worm variety) or protozoa. Very anticlimactic, I know. So was there any truth to the advice I just bought into? Or a bit of bestseller hogwash?

No, you don’t need a detox juice cleanse. Here’s why.

A waste of money?

Yes, parasite cleanses are worthless. You’re almost literally flushing your money down the toilet.

“For a long time, there have been people selling products with various health claims designed to separate people from their money,” says Thomas Moore, an infectious-disease specialist and clinical professor at the University of Kansas School of Medicine at Wichita. “Parasite cleanses are the latest incarnation of a pseudoscientific health trend that sells the idea that there are toxins in your body that need to be purged. In fact, what they’re really doing is preying upon the gullible.”

Manufacturers of parasite cleanse products will tell you that most people have parasites in their intestines and don’t even know it. They make parasites seem common and the culprit behind much of what ails us. The supplements they sell, which are often made of some mix of papaya seeds, walnut hulls, cloves and wormwood, claim to kill parasites in your intestines and expel them in your feces, where you can sometimes find their carcasses if you dare peek in the toilet.

“These homeopathic or naturopathic treatments are based on pseudoscience,” Moore says. “If you really have a parasite, getting it diagnosed is the most important thing to do because there are effective treatments. There’s little to no scientific data to support that these concoctions fight off infection.”

A 2007 study of 60 children in Nigeria suggests that eating dried papaya seeds might help clear parasites in the stool, but the small study doesn’t actually prove that papaya seeds eased symptoms because none of the kids had any. (Most people with worms do not have any symptoms of an infection.)

And about the photographic evidence that people post online (do yourself a favor and don’t look it up), what might appear like a worm could just be undigested bits of kale. “That long spindly thing in your stool can certainly look like a tapeworm if you don’t know what you’re looking for,” Moore says. “When in fact, it’s just a string of vegetable matter.”

Are the products safe?

These home remedies haven’t been shown to work against parasites, but could the supplements hurt?

“These supplements are really modern snake oil,” Moore says.

It might not be harmful to take these supplements if they were pure, consumed in small doses and safely made, says Omobosola Akinsete, an infectious-disease clinician at HealthPartners Medical Group in Minnesota. But they, like all supplements, aren’t regulated by the Food and Drug Administration the same way pharmaceuticals are, so their contents vary from place to place and there might be harmful ingredients in them.

At best, herbal supplements could have some benefits, but they also can be ineffective, or worse, contaminated with microbes or heavy metals, or intentionally spiked with illegal or prescription drugs. They also can cause harmful side effects and interact with prescription medications.

“These supplements and cleanses are also laxatives,” Akinsete says. “They cause diarrhea and, if taken in sufficient-enough quantities, can actually change the microbiome of the gastrointestinal tract, which is what we are trying to prevent in the first place.”

Parasites may not be cute and cuddly, but they need saving too, scientists say

Do you need to worry about parasites?

Parasitic infections are widespread at the global level, but not in the United States and other developed countries. But Moore says they can be a problem in populations that don’t have access to good sanitation — the same population that doesn’t have the disposable income to spend on pricey herbal supplements, which can cost up to $90 per bottle.

“Americans generally don’t need to be concerned about parasites as they are very rare in this country due to good sanitation, treated water supplies and close monitoring of food products by the government or other agencies who make sure it’s safe for human consumption,” Akinsete says.

Akinsete says, however, people should get tested by a doctor if they have traveled to a developing country and have symptoms such as diarrhea, abdominal pain, rashes and bloating. (Although Moore says that most cases of diarrheal disease are due to E. coli, not parasites.) The same goes if you experience these symptoms after eating raw food, such as sushi, or drinking untreated water while camping.

Regardless of exposure, Akinsete says that you don’t need to check for parasites if you don’t have any symptoms.

Can some parasites be beneficial?

Some researchers claim that expelling harmless helminths from your body works against you — that these worms work to balance out our gut biomes and prevent allergies and autoimmune disorders.

But Moore disagrees. “The word parasite derives from the Greek term for ‘uninvited dinner guest,’” he says. “These things tend to feed off of you, and they’re, by definition, not a good thing to have. But the best ones will cause no symptoms at all.”

I tried a cleanse to lose weight and feel better. All I felt was much worse.

How to have a happy, healthy gut

Rather than purge your bowels of a nonexistent parasite, Moore says the most important thing to do to maintain a healthy gut flora is to eat a varied diet that’s rich in vegetables, specifically leafy green vegetables. If you want to do something extra, consider taking a probiotic that contains lots of different bacteria and other anaerobes, which may be helpful for gut health.

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