Lutein: Eyes & Cooking

Hi, Jack. Have you ever heard about the role lutein, found in highest amounts in kale and spinach, plays in vision or eye health? I just watched a video (it’s 23, second from bottom on p.1) by Robyn Openshaw (the self-named Green Smoothie Girl) and she claims that she had really bad eyesight in college. Since then she’s had two to three handfuls of raw spinach a day (in smoothies) and she says that now her eyesight is 20/15. On another site, it says you’re supposed to cook the greens to release the lutein, so now I don’t know what to think.

Robyn Openshaw is misinformed about vitamin B12, saying in Part 2 of her GSG-SMOOTHIE 2.0 video that you can get it from brewer’s yeast, aloe vera, or a steak once every three years. Whether green smoothies improved her eyesight, I really have no idea. If they did, it could be any number of things in them, not just lutein.

All that said…Yes, lutein is thought to be good for protecting the eyes. I did a little research to see if lutein is better absorbed from cooked or uncooked spinach and it appears to be better absorbed from cooked, though the difference is not great according to this abstract.

It also appears that luetin is fat-soluble which should mean that eating some fat with foods high in lutein would increase its absorption. Fat soluble molecules are often better absorbed when cooked, but the one abstract above, the best one I could find, indicated that this is not the case for lutein.

6 Responses to “Lutein: Eyes & Cooking”

  1. Jack Norris Says:

    Comments from an ophthalmologist (sent to me privately):

    I’m very skeptical that lutein improved her vision. If she were vitamin A deficient, then lutein might have some value. Otherwise, I can’t see such an effect from lutein. If there is any truth to the claim that her vision actually get better, the most likely cause is that her refractive error changed over time such that her vision without glasses improved. Refractive error changes with age, most notably during teenage years and then in later years when cataracts start to develop. I strongly doubt the smoothies had anything to do with it.

  2. Andreas Says:

    Lutein and eye health.

    Lutein and colon cancer.

    I am skeptical about taking solely lutein supplements since plant foods are rich in other phytonutrients.

  3. Josh Says:

    Hey Jack!

    Sorry if this is not a relevant article to ask this question on – I’m asking it here cos this is one of three articles by you that mentions raw kale.

    Q: are daily raw kale smoothies safe? I love to blend a bunch of kale, banana, orange, and water in a smoothie, however some of my family are querying whether raw kale causes health problems (such as thyroid problems). I couldn’t find any peer-reviewed science on the matter, hence why I am asking you.


  4. Jack Norris RD Says:


    I have no reason to think that a daily kale smoothie isn’t safe.

  5. Josh Says:

    Thanks Jack.

    While on the topic of smoothies, I see you wrote:

    “Some plant foods are high in oxalate and spinach is extremely high. For most vegans, oxalate won’t be a problem, but if you decide to start juicing or blending your greens, make sure you don’t consistently use large amounts of the high oxalate greens (spinach, swiss chard, and beet greens) – doing so could result in a kidney stone.” (

    What would be a safe amount of spinach to juice or eat each day? Does baby spinach have the same oxalate content as regular spinach?


  6. Jack Norris RD Says:


    I don’t know whether baby spinach’s oxalate content is different than other spinach. I also don’t know how much spinach is safe each day, it probably depends on how sensitive you are to forming kidney stones which seems to vary quite a bit from person to person. I’d probably stick to no more than a cup a day, but I’m just basing that on what seems to be a normal amount that doesn’t cause problems for most people. Once you start eating more than that, you’re probably getting into territory that is more unusual and thus could be risky. If you’ve had oxalate kidney stones in the past, I’d stay away from spinach for the most part.

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