Friday Favorites: Are Pre-Cut Vegetables Just as Healthy?

Endotoxins can build up on pre-chopped vegetables and undermine some of their benefits.

Here are those old videos I mentioned: The Exogenous Endotoxin Theory ( ) and Dead Meat Bacteria Endotoxemia ( ).

For some other practical veggie vids check out Best Way to Cook Vegetables ( ) and How to Cook Greens ( ).

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-Michael Greger, MD FACLM

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Dave McKinnon

  • andrew pawley says:

    I love this channel!

  • Belinda Knowles says:

    Have there been any studies on chopped frozen vegetables?

    • Western Gardenia says:

      This doesn’t completely answer your good question, but some frozen chopped vegetables (such as broccoli) have another problem. They are cut then blanched before freezing. The blanching process destroys a key water-soluble enzyme (myrosynase) in the vegetable that then prevents formation of the desired sulforaphane phytochemical. One work-around is to add ground mustard seed when serving the de-frosted broccoli.

      I don’t know this to be a fact, but my understanding of the frozen food industry is that the entire process is typically automated so that chopping, blanching, then flash-freezing is done quickly by machine. Once flash-frozen, the vegetables would no longer have bacterial growth. I would therefore guess that machine processed frozen vegetables have very little bacteria.

    • Belinda Knowles says:

      @Western Gardenia thanks. This helps. 😊

  • KST says:

    It’s far cheaper (as well as healthier) to cut & chop your own + it lasts longer as the rest isn’t chopped up + less waste + more health gains to your body (compared to shop pre chopped). Lots of pluses… 👍

    • CatC says:

      and there are plenty of gadgets to help if you have conditions that make regular chopping difficult….love my Veggie Bullet!

  • Marcella says:

    I didn’t know how dangerous cooked poop was… until now.

  • KrazyKrzysztof says:

    my store traderjoes only sells chopped cabbage unfortunately but everything else I buy is not pre chopped

  • Linkchu says:

    would this effect happen with cooked vegetables aswell? I usually prepare them in bulk and store them in the fridge for the next 5 days.

  • Agnes Nutter says:

    I love my plant based health results but also the occasional McEndotoxin sandwich. What to do?

  • Happily Vegan Since 2000 says:

    Good to know this. Thanks. Here in India pre chopped not much of a trend still it’s good to know this. I always chop myself, never use pre-chopped.

  • sudd says:

    that is why they all say whole plant foods, the more you process them and longer you store them the worse it gets.

  • Mike's Vegas says:

    Pre-Cut Fruits are not safe either, and very pricey 😬

  • Michael Mackey says:

    Great video

  • Julià Arcau says:

    I usually buy whole vegetables in good quantities and chop myself, mix and keep freezed (to be steamed) or fridged (to be eaten raw) in portions of 3 to 4 servings.

  • David Hochstettler says:

    Do I need to start chopping my kale? Instead of buying the bags triple-washed chopped version?

  • aroundandround says:

    0:16 Okay, so if you’ve lost your egg and sausage sandwich virginity, having already destroyed your arterial health, you might as well give up and wallow in egg and sausage sandwiches for the rest of your short life.

  • aroundandround says:

    Why is increased inflammation like in the Onion study bad? It goes away quickly and is painless for almost everyone eating pre-chopped.

    • Western Gardenia says:

      The inflammation markers that they used, TLR2 and TLR4, indicate the presence of gram-positive and gram-negative bacteria respectively. TLR2 and TLR4 are receptors found on innate immune cells such as dendritic cells and monocytes. The presence of inflammation therefore indicates a bacterial infection that is being fought by your immune system. This would not be such a problem if the infection were quickly handled, however chronic long-term inflammation damages your vascular system and organs. If one eats badly all the time, then the inflammation is always present (causing damage).

  • Kathy Sharp says:

    I hear and understand. I’m still going to buy prechopped cabbage, and I’m still going to make my breakfast salad before bed (which almost always is low fat and sos free). But, I will memorize this detail in case I ever need some extra anti-inflammatory boost. Life is a balance of limited resources. But, I love learning about all the research, so I can make informed decisions (good or bad). Thanks Dr. Greger and team!

  • Kathy says:

    If using pre-cut veggies leads to eating more vegetables than it is certainly worth the extra cost.

  • Diane Ladico says:

    Interesting. I chop a lot of veg to keep in the fridge for quick meals and snacking.

  • MrLeviathoth says:

    Here’s something interesting to add. What it means I’ll leave to all of you. I have two pigmy goats and they love vegetables, even freshly cut; but if I give them frozen precut veggies (takes a few minutes to thaw outside, btw) they not only ignore them like they’re poop, they give me the stink eye like I played a bad joke on them. Subtle humor aside, they will NOT touch the purchased frozen precut veggies, whereas, they will devour fresh uncut veggies (like kids given free rein in a candy store), even if they were *refrigerated first. Go figure.
    *Note: I refrigerateed them for only one day to serve them the treat on Thanksgiving.

    Dunno if the reasons are applicable to this video, but I will say I always assumed that wherever these precut veggies were sourced, that wherever they were sourced failed to list some chemical spread over said veggies. In fact, it’s because of this is why I now only eat fresh veggies and not the frozen (more convenient) veggies sold in stores. Thoughts? Please share. Thx.

    • Paul Ramsey says:

      Frozen broccoli tastes awful to me so clearly freezing some veggies affects them. I’ve used frozen riced cauliflower and it seems fine though it tends to get mixed in with spices and such better so maybe the bad flavors are more hidden.

  • mitch X says:

    Good stuff doc. My donations are well spent on your information

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