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Brain Parasites in Meat

What percentage of U.S. lambs are infested with toxoplasma parasites?

November 25, 2009 |
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Supplementary Info

Sources Cited



Next up, lamb chops. The prevalence of the parasite toxoplasma in lambs destined for human consumption in the USofA. USDA researchers obtained the hearts of 383 lambs on the day of killing. So for those who think the USDA doesn’t a heart? Wrong—they’ve got 383!
What do you think they found? Greater than 50% infested? Or less than half?
The good news, is that it was less than 50%--only about 1 in 6 U.S. lambs are actively infected. The bad news is that 10% of Americans are currently infected with this brain parasite. That means odds are we all know people who have a battle going on inside their skulls between their immune system and these toxoplasma parasites, which have been linked to schizophrenia, bipolar disorder, and Parkinson’s, but most people’s immune systems are able to keep them at bay.
Should our immune system start to seriously slip, though, they can infect our eyeballs, here’s a closeup. This is what it looks like in the brain of an adult. And this is what these parasites can do to the brains of our children.
No one, but particularly pregnant women, should eat undercooked meat.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring watch the above video. This is just an approximation of the audio contributed by veganmontreal.

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Dr. Michael Greger

Doctor's Note

Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out theother videos on parasites. Also, there are 1,449 other subjects covered in the rest of my videos--please feel free to explore them as well!

For more context, check out my associated blog post, Adding FDA-Approved Viruses to Meat.

  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other videos on parasites. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

  • Toxins

    wow, how would I go about getting tested for these brain parasites mentioned in the video and the parasites found in fish in ur previous videos? I’m afraid something might be incubated inside me (been vegan for 9 months) and I wont even know it.

  • rebecca

    I was informed that i have had toxoplasmosis.Steak Tartare was on many menus in the 70s,as well as our affection for rare meat.Does this mean the parasite is alive still?
    There was no treatment recommended,just the information that I had had it.

    • Don Forrester MD

      Up to 20% of US citizens have been exposed to Toxoplasmosis. Even if you have a blood test and it is determined that you were exposed unless you have symptoms there is no treatment recommended. Since it is rarely a problem except in patients with impaired immune system such as AIDS. The CDC has an excellent website which should answer your questions.

      • rebecca

        So does the parasitic worm still live?With a good immune system does your body defeat the parasite & thusly you have Toxoplasmosis anti-bodies appearing?

  • Dan Lundeen

    According to Flegr men infected with T. gondi have subtle behavioral differences, e.g., loss of coordination/reflex time (manifested in double the car crash rates in statistical surveys of military personnel) and an affinity for women with cats. In the life cycle of the parasite it infects rats who then lose their fear of wide open spaces, lose reflex time and develop a sexual arousal from cat urine, increasing the chances of being eaten by a cat. People blame cats for T Gondi, but the infection is more commonly acquired by undercooked lamb consumption as Dr. Greger notes.

  • mgibson

    My 18 year-old nephew has just been diagnosed with bipolar disease, so am researching the disease. Would treatment for toxoplasmosis make sense? I am heartsick, and would appreciate any help.
    Thank you

    • guest

      Omega 3′s (DHA supplements) have been contraindicated for people with bi-polar. This means DON’T TAKE DHA SUPPLEMENTS, AND DON’T TAKE FLAX, CHIA, HEMP or other high omega 3 foods. High omega-3 has been known to cause really bad reactions in bi-polar patients.

  • Hattie

    love your videos, thank you for all that you do. Do you have any other research on bipolar and diet please?