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Are Avocados Good for You?

Persin, a natural toxin found in avocados, appears so effective at killing breast cancer cells that it is being considered as a chemotherapy agent.

October 7, 2011 |
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Supplementary Info

Sources Cited


Images thanks to MariuszBlach, YinYang, and SCIENCEphotoLIBRAY


I’ve covered high-fat plant foods in the past such as nuts,  which are health-promoting,  coconut oil, which is,  not so health promoting, but  what about avocados. 75% calories from fat, but good for you none the less, neither good nor bad, or something we should consider avoiding? 

Well,  Rats, fed the human equivalent of 200 pounds, of  avocado seeds don’t do so well. But we’re not rats, and who eats avocado pits?

 Then of course the FDA warns about the  toxicity of avocado leaves, for the lactating mammary gland of the goat, but what about the actual fruit?  Not good for pets evidently,  but neither is chocolate. What about the actual fruit for actual humans? We have been eating avocados for 10,000 years, the darling of health nuts everywhere. What could possibly go wrong?

 Well, they’re not a problem for cholesterol, in fact people put on an avocado diet, see a  significant improvement in their cholesterol,  probably in part due to it’s phytosterol content.

The California Avocado Commission even supported a study pitting, no pun intended, hass avocadoes again a malignant line of oral cancer cells.  Here's the control. The red dots indicate living mitochondria inside the cells, the little sparks of life force,  extinguished by an avocado extract leaving dead lifeless husks of cancer cells in its wake

 Kills breast cancer cells too. There a natural plant toxin, produced by the avocado tree, that acts as a fungicide, an insectide, and can do a number on human breast cancer cells.  And here they are.

These are not what you want in your body. These are three breast cancer cells huddled together, planning their route of attack. This is a different stain than before. Here the red is their nucleas, and the green is their cytoskeleton, the cells skeleton. Didn’t know cells had skeletons? How else could they move?

 How else could a breast cancer cell get from the breast to the brain or to the liver, it crawls there.  Here's a video breast cancer cells in a lab working their way way through a maze researchers set up for them; using their cellular skeltons to pull themselves along.

Ah, but  that’s what chemotherapy is for.  This is what the chemo drug paclitaxel can do: Clumps up the cytoskeleton, so the cells can’t move, can’t divide. And the avocado toxin can do the exact same thing, stopping breast cancer cells in their tracks.

The researchers conclude that persin should be further evaluated single agent combination chemotherapy agent for cancers of the breast, maybe other cancers too.

 Look what it does to cancer cell DNA. This is a measure of DNA fragmentation, the avocado compound rips their chromosomes llimb from limb. Unfortunately, it appears to do the same thing to normal cells too.

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 Dianne Moore.

To help out on the site please email

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. Be sure to check out the other videos on avocado as well as breast cancer. Also, there are 1,449 subjects covered in my other videos–please feel free to explore them!

For more context, check out my associated blog post, Stool Size and Breast

See tomorrow's video Are Avocados Bad for You? and the follow-up Any update on the scary in vitro avocado data?

  • 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. Be sure to check out the other videos on avocado as well as breast cancer. Also, there are 1,449 subjects covered in my other videos–please feel free to explore them!

    • Lilly

      Why does the Gerson therapy recommend low fat foods. Avacados are on their forbidden list because of the fat content.

  • maybush1

    So, I assume that since avocado persin “rips cancer cell’s chromosomes apart from limb to limb” and that it does so in “normal cells, too” that avocados are NOT good for you? My poor avocados! Must I really say goodbye?

    • Michael Greger M.D.

      Unholy guacamole? Don’t shoot the messenger! The ending is just a preview of Monday’s continuation of the avocado story and there is indeed some concerning data. Let me know if you have any followup questions after watching part 2.

      • SMO404

        This is truly a cliff-hanger!! :-) I love my avocados so I’m really going to lose sleep this weekend until part 2 comes out. (Great site by the way!) :-)

        • Kmbrly

          Me too! I was literally eating avocado on (whole grain) toast as I watched this video – feeling quite smug that of course the answer would be a resounding YES! Avocados are absolutely good for you!

          What should I do with the other half of my avocado? How can I possibly wait until Monday to find out??

  • SArmstrong

    Bim-dependent apoptosis?? Man, I love it when that happens to cancer cells…….

  • Chris Brogan

    My cholesterol came in at 239, HDL 81 and LDL 160.  I eat mostly fruits, vegies, nuts, and fish.  I also exercise at least 3 times a week.  At 5’9″ 128 lbs, I feel in great health.  If I completely cut out the occasional piece of cake (about 3-4 times a year), will that lower my cholesterol?

    • Don Forrester MD

       In my clinical experience it isn’t the occasional stuff that gets us in trouble and it would depend of course on the recipe for the cake (e.g. vegan vs non-vegan). To lower your cholesterol you need to avoid all animal products as they all contain cholesterol. Avoid all saturated fat which the body makes into cholesterol. Saturated fat is found in all animal products plus processed oils and is even higher in some plant foods such as coconut oil than in butter see It is somewhat complicated see and the other videos on saturated fats plus the videos on Omega 3′s.  So the first step in your diet would be to stop the fish… see any of Dr. Greger’s 60 videos for reasons to avoid fish from the cholesterol and saturated fat to toxic chemicals  such as mercury to carcinogens such as dioxin to other substances such as medications. The exercise is helpful in many respects but has a minor effect on cholesterol about a 1-5% reduction depending on amount. Dr. John McDougall has information on his website under Hot Topics which you might find interesting and useful. It is important to work with your physicians for further modifications.Good luck.

  • Angela Banks


  • bee

    How much avocado would a person need to eat for it to be harmful?

    Are there ANY foods that u recommend people focus their diet on?  lol

  • susano22

    so am I to take from this that limiting the intake of guacamole should be observed? I am so vexed by this whole diet thing. I gave up white refined anything, grain, starchy root veggies, fast food (which I never really ate anyway) I eat organic at every turn, lots of veggies and yet I still seem to have digestive issues both upper and lower and have sneaking suspicion that I am suffering from some sort of inflammatory condition. I did not give up alcohol and have 2 drinks a day, mostly wine and 2 cups of 1/2 caf a day as well. Those are my only vices…… where do I go from here eradicate what feels like acid indigestion…. I tried all the ppi’s to no avail except having to wean off…..

  • Roberto

    Hi Doctor, my name is Roberto. I am a fruit and vegetable consumer and I generally don’t eat meat or dairy. I eat plenty of avocado howerver. I was wondering, should I stop eating avocado?

  • Pam

    Not very happy as I have been eating them almost daily for over a year and love them!!!! What’s a girl to do?