The Safety of Graviola

Every couple of years someone publishes a research paper saying graviola causes neurotoxicity or the main anticancer chemical, annonocin, is a neurotoxin and it’s unsafe to take graviola supplements. I’m going to share my personal experience and provide you with my educated opinion of these studies and let you decide for yourself whether graviola is dangerous to take.  These are my opinions only, based on my research and my personal experience… do with it what you will and make your own decisions about your own health.

I’m writing this quickly without going back to completely review all these old studies. I just don’t have the time right now, so am going to summarize. The very first study reporting the neurotoxicity of graviola extracted graviola in methanol or ethanol (don’t remember which) and injected directly into some lab animals’ brains (mice or rats). This study reported graviola was a neurotoxin because it caused cell death in the brain. At the time, I said okay… my customers buying graviola weren’t injecting their supplements into their brain, so no worries.  I knew lots of stuff, even just the methanol, would cause cell death if it were directly injected into the brain. I also knew this certainly did NOT prove graviola could make it over the blood-brain barrier into the brain in the same fashion when it was ingested orally.

Then this isolated, economically disadvantaged community in the West Indies (Guadeloupe) came down with some unexplained Parkinson’s Disease-like symptoms (trembling, shaking, tics, etc.). They were interviewed about what was in their diet, looking for what that might be a dietary/environmental cause. Like most people in the tropics, graviola fruit was in their diet, and they also used a graviola leaf tea as an herbal remedy occasionally when needed. They weren’t eating or drinking both daily. The researchers assumed (or wanted to believe) it was the graviola because of the previous “neurotoxic” study which injected graviola into the brain. They did another study “to prove it,” this time injecting just a graviola chemical called annonacin into the brains of lab animals. They again reported cell death, especially to certain dopamine-type brain cells which might possibly cause  some of the same sort of symptoms (lack of dopamine causes/worsens Parkinson’s). In this study they reported graviola causes Parkinson’s-like symptoms because it has neurotoxic compounds and cautioned people not to take it. They, of course, never determined graviola compounds and annonacin specifically were actually in the brains of these people or proved it was graviola that caused their shaking – it was still just a correlation or possible link based on a dietary questionnaire when they published this study.

A while later is was determined that the diet of these people were nutritionally deficient and that was the cause of their symptoms. I think is was several of the B vitamins severely lacking, but won’t take the time to go back and look it up. They cured these people of their Parkinson’s-like symptoms by fixing the nutritional deficiency (not by removing graviola from their diets). But for years, graviola was attributed with this incorrect link and a warning that graviola might cause Parkinson’s-like symptoms because of “possible neurotoxicity.” I’m STILL seeing this incorrect association in some of the research they’ve continued to publish trying to somehow prove graviola is somehow unsafe and is neurotoxic and the science gets even more convoluted trying to prove this concept.

Convoluted? My opinion of course, but let me give you an example. In 2015 they published a research paper that reported: “These results demonstrate that the intake of dietary supplements containing plant material from Annonaceae may be hazardous to health in terms of neurotoxicity.” Based on what? On an in vitro (test tube) study. First, they extracted 3 different Anonna plants (including graviola) in hot, pressurized, ethyl acetate (a toxic, flammable chemical you have to wear protective equipment to handle) Logically, nothing like what happens when you take some leaf capsules or leaf tea by mouth and it goes through digestion, right? What gets “extracted” in your stomach logically isn’t what gets extracted under heat and pressure in a toxic chemical that’s found in your nail polish remover that strips polymers off your nails. Right? Logically, speaking of course.

Then they put some “brain cells” in some little cup holders/wells. But they didn’t really use brain cells, they used “Lund human mesencephalic neurons.” You purchase these from a lab that grows them and sells them for research purposes. These are actually undeveloped, precursor brain cells that came from an 8 week old human embryo/fetus. Logically, these cells are not present in your brain or mine, and I’m assuming they’d be a tad more delicate than a fully formed brain cell. That’s an assumption, I haven’t bothered to look it up. So, they mixed these fetal precursor cells directly with this toxic-nail-polisher-remover graviola extract in the little cup holders, waited 48 hours and said: “Wow, this extract killed 67% of these delicate precursor cells!” Therefore, Annona plants are neurotoxic and taking a graviola/Annona supplement is harmful for you to take. Huh? Wait. What?

Personally, I’m not worried that what I eat or drink is going to be digested and extracted in the same manner as they extracted it. I won’t be washing my supplements down with nail polish remover either. I don’t logically think it will be absorbed in my bloodstream thru normal digestion in the same manner and somehow make it thru my blood-brain barrier meant to keep most things out of my brain.  I don’t logically think it will come in direct contact with my brain cells like it did in the little cup holders and have the same effect they demonstrated in this study. But hey, that’s me. I’m way logical, and now that you have the facts about this study, you can draw your own conclusions.

I think if I sold about a million bottles of graviola supplements over 15 years (which I did) and was killing 67% of my customer’s brain cells in one dose, someone would have said something. They didn’t, and graviola didn’t. Also, never once, did we get any report of anyone taking these supplements having Parkinson’s-like symptoms. Not one. And the next study they published a year later proved it.

This one was just as convoluted in my personal opinion, but I need to discuss it because it refutes all prior studies of brain cell death/toxicity. Again, you can decide yourself. This time, they went in the lab to prove that long-term daily consumption of graviola fruit juice causes neurotoxicity. I’m just assuming graviola juice products had gained in popularity enough to target this then. But they didn’t use regular, normal mice for the study. They used mice that carried a genetic mutation in the brain which causes a weaker blood-brain barrier and the inability to clear out substances from the brain once it gets in the brain so it has a build-up/residual effect. This genetic mutation isn’t very common in humans and is present in a very small percentage of people, living mostly in Northern Europe and Japan. The mutation also creates more of a brain protein called tau. They justified using these mutated mice because MAYBE the nutritional deficiency in the West Indians could have POSSIBLY created a similar condition (weakened brain barrier and/or inability to clear substances from the brain) but this was never confirmed in the actual patients who had Parkinson’s symptoms who were cured by just fixing the nutritional deficiency. Convoluted? You decide. What I see in reading thousands of studies, is that researchers can easily set up their study protocols to prove exactly what they want to prove before the study even starts. Just my opinion, of course.

So, they gave one group of the mutated mice only graviola fruit juice to drink instead of water for an entire year. (!) Won’t take the time to go there. (sigh) They gave another group of mutated mice water to drink instead and compared the groups. The lifespan of a normal mouse is about 5 years (I haven’t bothered to looked up the lifespan of these mutated mice) but that would be about the equivalent of a human drinking nothing but graviola fruit juice instead of water for like 10 years or more. (Which of course, I would never do and you shouldn’t either.) If I believed the previous study of killing 67% of their brain cells with one dose, I would have assumed these mice wouldn’t have made it a year. But they did, and when they examined their brains after a year of this chronic use, there was no cell death in the brain, no astrocyte cell loss, no loss/death of dopamine-type cells or any of the other cell death claimed in all the other studies (that manipulated graviola or its main annonacin compound over the blood-brain barrier in some fashion – just as this study manipulated it over the barrier with the mutated gene causing a weakened barrier).

None. Nada. Zip. They also didn't see any "Parkinson's-like symptoms" in these mice (even the mutated mice) for the entire year the mice drank the graviola fruit juice.  What it did do was aggravate the genetic problem of too much tau (that isn’t present in MY brain) and caused some pro-oxidant damage to the excessive tau in their brains. There was also a little bit of oxidation in the non-mutated mice’s tau but no-where near the mutated ones. This oxidation, in my personal opinion, could possibly be related to drinking only fruit juice (any kind of fruit juice) instead of water for like 10 years, which might just cause some oxidative free radicals. Who would do that? Not me. This oxidation could also have been the chronic buildup (mutated barrier) and effect of the three chemical preservatives in the fruit juice these mice drank too. Again, if I have to say it, you shouldn’t do this either. Water is good for you; drink lots! Chemical preservatives can be bad for you; avoid them when you can and don’t take them chronically like that.

Several other studies have been published over the years about graviola and neurotoxicity but they were injecting graviola extracts (which contained various toxic extracting liquids) or just the isolated annonacin directly into the bloodstream (intravenously) to get it over the blood-brain barrier. One study even put it in one of those chemo or pain medication drug pumps that pumped it into the bloodstream continuously over 3 days. Some injected it under the skin or in the muscles, like a regular shot would. These studies all claimed neurotoxicity to various brain cells in their published research by manipulating the method to help get it over the blood-brain barrier. Again, nothing like what happens when someone drinks a tea, takes a capsule, or drinks some juice and it goes through the normal digestion process. And this mutated mouse study confirms the neurotoxicity these studies reported simply doesn’t happen when the leaf or juice is ingested (not injected).  They also proved the long-term consumption of graviola fruit juice does NOT cause Parkinson's-like symptoms in mice.

But studies still keep getting published that it does and that graviola is a neurotoxin. I won’t go there on why I think they are. Let’s just acknowledge they are and leave it at that.

One recent study again reporting neurotoxicity I read yesterday made me laugh out loud. Researchers have this mutated flat worm they use to determine if a plant or plant compound might be “anti-aging.” This worm is mutated in a special way, so that if you can prolong the short life of this worm with some compound or plant, it indicates you might possibly prolong the life of humans. I’ve seen a lot of this research using this worm on the Amazon plants I’m updating since it targets possible anti-aging compounds for further research. Anti-aging plants/chemicals/products/supplements are of great interest to researchers these days. Anyway, they exposed these mutated worms to a graviola extract. They produced about 20% fewer eggs and didn’t wiggle around quite as much. They said this was because graviola was “probably neurotoxic.” [insert laughter here] Graviola is used as an insecticide and it’s a documented antiparasitic (against various worms); I was shocked graviola didn’t kill these wigglers and wondered just how they had mutated them!! Before I found out about graviola and cancer, my main use of graviola was as an ingredient in my herbal remedy to kill parasites and worms. Several new studies continue to report that graviola can kill intestinal worms and parasites in animals and humans. 

So, let me summarize. The way I personally avoid all the documented/researched/published "brain toxicity" from graviola is: A.) I don’t extract it (especially in toxic liquids) and inject it into my brain. B.) I don’t go thru a complicated process to just extract annonacin from graviola and inject that in my brain either. C.) I never ever inject graviola or annonacin in any form directly into my veins or under my skin, or in my muscles either (or put it in a “pain-pump” to inject it into my bloodstream regularly over many days at a time). D.) And I never ever use or take graviola chronically every day. I am going to tell you why in another blog because I know some people are doing this. Go here to see why I think it isn’t necessary or helpful to do so. And btw, if I have to say it, I would advise you to not do A thru C above either. Sheesh!

I should probably take the time to remind everyone; graviola is a popular fruit in Brazil and throughout Latin America. The fruit is sold in markets and grocery stores, fresh and canned fruit juices are widely sold and the fruit is often prepared in ice creams, syrups, candy, shakes and other beverages. I can even find standard graviola fruit juice at my grocery store in Texas sold under the Spanish name, Guanabana with the rest of the canned fruit juices and nectars (unfortunately loaded with high fructose corn syrup).  Outside of the one isolated case in the West Indies that was proven to NOT be graviola, there has not been any outbreak of Parkinson's Disease, or Parkinson's-like symptoms any where in Brazil, Latin America or North America, for that matter, where graviola supplements have steadily gained in popularity.  An search I just did, linked to 542 products searching for "graviola supplements."

So, these are my personal opinions; you can do with them what you will and make your own personal choices about your health. Look up these studies on PubMed and read them like I did and form your own opinions about them. I haven’t shown any of the neurotoxic studies in graviola’s plant database file either for all the obvious reasons I’ve discussed. I believe these studies just aren’t applicable to how graviola is used as an herbal supplement today which is what my online plant database is about.

As always, stay tuned! More to come… Don’t forget to read why I personally don’t use graviola chronically/daily or for “wellness”“cancer prevention” or “immune health.”


  1. Dr. Taylor, I like your thinking and I am familiar with the sketchy semi-scientific (my term for junk and sloppy science that doesn't rise to any generally-accepted clinical level of worthiness that I am aware of) . Question. What is your opinion of Graviola as a regulator of blood pressure and, as a separate matter, blood sugar? One more thing - out here in readerland we're loving your blog! Thank you.

    1. You're welcome and glad you're liking it! Follow the link above about the chronic use of graviola in the other blog article I just uploaded. I don't recommend the chronic use of graviola unless I am treating cancer because of the ATP inhibitor action that graviola does so well. You'd end up treating both hypertension and diabetes chronically and I just think there are better plants that will work just as well that won't inhibit energy to healthy cells if there are no cancer cells for these ATP inhibitor compounds to gravitate to. I've often seen patients need to adjust their hypertensive drugs when they were taking graviola for cancer because it does indeed lower blood pressure. But the heart has high energy cells and needs all the energy it can get especially if they are taking statin drugs. I wouldn't want graviola lowering the ATP in my heart cells if I had some kind of heart disease that was causing hypertension. Same thing goes for blood sugar/diabetes.

  2. Your points are high speed, easy to digest - and make a very good case regarding the use of graviola in the regulation of blood sugar and blood pressure. Thank you.


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