The Parasite Connection to Your Mood and Mental Health

March 14, 2023

A common parasite that changes your brain chemistry may be the missing link in everything from road rage to depression – and even autism and neurodegenerative diseases.

Amelia loved growing her own vegetables, without the use of chemicals and pesticides. Dirt under her fingernails was a sign of a life well-lived in her opinion, and there was nothing better than snacking on snap beans while she worked. But once a stray cat started coming around and using her garden as a litter box, everything changed.

Soon after the cat started coming around, Amelia came down with what she thought was a summer flu. Fatigue, fever, headache, body aches, and swollen glands plagued her for more than a month, then slowly started going away. She wasn’t able to get out in the garden much but didn’t mind because she didn’t have the energy anymore. It wasn’t long before she lost interest in gardening altogether, as well as other activities she loved, and eventually was diagnosed with depression.

Being naturally-minded, Amelia looked for alternatives to medications for her depression. In her research, she discovered toxoplasmosis, a common parasite that is spread through cat feces, eating unwashed fruits and vegetables, or undercooked meat and shellfish, might be the cause of her depression. She asked her doctor for a blood test and it was positive.

Toxoplasmosis: The Hidden Enemy Within

Toxoplasmosis is one of the most common parasite infections in humans, with over 40 million Americans currently infected, according to the Centers for Disease Control (CDC). After the initial infection – which may act like flu, food poisoning, or be totally asymptomatic – this parasite travels to brain and muscle tissue where it forms into cysts and can stay, undetected, for the rest of your life.

Previously, toxoplasmosis was thought to live in your tissues long-term and cause no harm, but it may actually be the missing link in many mental health disorders. Decades of research has been done into the behavioral connection to even a mild infection with toxoplasmosis, linking this parasite to depression, anxiety, impulsivity, anger, aggression, rage, bipolar disorder, schizophrenia, obsessive compulsive disorder, epilepsy, autism, neurodegenerative diseases, and even certain cancers. And mice have only recently shown us how this could be happening.

It’s Not All In Your Head

It’s a common misconception that all mental illness originates in the brain. The truth is, our microbiome – the collection of microorganisms living inside of us – sends and receives messages to and from our digestive and nervous systems, and makes 90 percent of the neurotransmitters that determine our moods and mental health. All it takes is one bad bug – like toxoplasma – to upset the whole balance and change our moods, mental health, and even our personalities.

Toxoplasma is the reason pregnant women are advised not to handle a cat’s litter box – infection with it can cause severe neurological problems in the developing fetus. Cats are the only known host in which this parasite can reproduce, and they shed the eggs into whatever they use as their litter box. Once you or your food touches that cat litter or contaminated soil, these microscopic eggs pass on to you. If you don’t wash yourself or your food well, or contaminated meat and shellfish are undercooked, the parasite eggs live and you become infected, and this infection does travel to the fetus in a pregnant woman.

Biologically, it’s the same with mice, but researchers noticed something interesting – once a mouse is infected with toxoplasmosis, it’s no longer afraid of its most notorious predator, the cat. This greatly benefits the toxoplasma parasite, because the infected mouse is eaten by the cat – the only known host where this parasite can reproduce and continue its life cycle. Researchers from the University of Leeds discovered what’s behind their strange behavior, and it begins to explain why toxoplasmosis affects human behavior so dramatically.

Once you are infected through your digestive system, this parasite quickly goes to work on your nervous by changing the way your brain sends and receives signals, by altering the quantities of over 300 proteins needed for those signals. One of the signals interrupted involves glutamate, and malfunctions in this area of signal processing are associated with depression, schizophrenia, and autism.

The changes to your brain metabolism don’t end there. Not only do these immune reactions increase inflammation and change the messages going to your brain, it also changes the levels of one very important neurotransmitter – dopamine. Researchers found this parasite dramatically increases your dopamine levels, which changes how you control movement and behavior, regulate emotional responses, and increases stimulation to your pleasure-seeking and reward centers, much like addictive substances do. The increase in dopamine explains why the mice were no longer afraid of their cat predators, and may shed light on disorders like schizophrenia, ADHD, autism, and neurodegenerative diseases like Parkinson’s.

What You Can Do To Support Your Moods and Mental Health

Not everyone finds their answers as quickly as Amelia did; many people are never tested for Toxoplasmosis or even realize they could’ve been exposed. And once it dives into deeper tissues like the brain and muscles, it may not be detected on a blood test, but still may be causing inflammation and wreaking havoc on your nervous system. Fortunately, there are ways to support your brain and your body to reduce inflammation and parasite infection:

1. Cleanse Your Microbiome.

It only takes one “bad apple” but the truth is there may be more than toxoplasma hiding in your microbiome causing trouble. Once inflammation sets in, it’s more difficult for your immune system to fight off these foreign invaders. This is why I recommend a thorough cleanse to combat these hidden hitchhikers with gentle yet effective herbs, and repopulate with safe probiotics. I have relied on UNI KEY Health’s 30-Day Parasite Cleanse Kit with my clients and readers for almost 30 years. The Verma-Plus and Para-Key formulas in the kit contain herbs that help target not only adult parasites but parasite eggs. The kit also contains Flora-Key, a probiotic powder to repopulate the GI tract with healthy bacteria to help restore healthy neurotransmitter production. I also take Para-Key with me whenever I travel, to help offset any exposure I might have.

2. Add Essential Oils to Your Arsenal.

Three essential oils have been found to help inhibit toxoplasma infection. Thyme oil was found to be effective against brain cysts in mice, nutmeg oil was comparable to antibiotics in its testing, and black cumin seed essential oil reduced the transmission of toxoplasmosis and slowed its progression in studies that were done.

3. Add Anti-Parasitic Foods to Your Diet.

Cultures all around the world have added foods to their diets that naturally inhibit and fight parasitic infections. Because the United States is such a melting pot, we’ve lost touch with some of these health protective traditions, but there’s no reason we can’t incorporate worldly wisdom into our modern diets. Daikon radish, garlic, radicchio, papaya, pineapple, pumpkin seeds, pomegranate, turmeric root, coconut, ginger, cayenne pepper, carrots, and lemon are all delicious, powerful anti-parasitic foods to incorporate into your daily diet, not just during cleanses.

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Ann Louise Gittleman, PhD, CNS, is an award-winning New York Times bestselling author of more than thirty books including The Fat Flush Plan series and her latest book, Radical Metabolism. She’s been rewriting the rules of nutrition for more than 40 years and is internationally recognized as a pioneer in the field of diet, detox and women’s health issues. 

For a FREE daily dose of tips and strategies for maintaining healthy weight, conquering insomnia, and much more…check out my Radical Health Tips.

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  1. Jody

    With the essential oils, do you ingest them or apply topically? How much do you take?

    • Team ALG

      Jody, The safest way to ingest essential oils is in a capsule, preferably a manufactured gelatin capsule that will dissolve in the small intestine. You can fill your own capsule with the essential oil mixed with vegetable oil but it will probably only make it through to your stomach.

    • Deb

      I take oils internally all the time by capsule or by adding a few drops to water, juice. I do make sure my oils do NOT say, “Do not take internally.” If they do that means they are not pure but have some sort of additive or synthetic.



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