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Dietary Prevention of Age-Related Macular Degeneration

Yellow plant pigments such as lutein and zeaxanthin build up in the back of our eyes to protect our retinas against age-related macular degeneration. Levels of these eyesight–saving nutrients in organic free-range eggs, vegetables, and goji berries are compared.

December 30, 2013 |
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Supplementary Info

Sources Cited

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L. Ma, H. L. Dou, Y. Q. Wu, Y. M. Huang, Y. B. Huang, X. R. Xu, Z. Y. Zou, X. M. Lin. Lutein and zeaxanthin intake and the risk of age-related macular degeneration: A systematic review and meta-analysis. Br. J. Nutr. 2012 107(3):350 - 359.

R. D. Glickman. Ultraviolet phototoxicity to the retina. Eye Contact Lens. 2011 37(4):196 - 205.

Y. Liu, X. Song, Di Zhang, F. Zhou, D. Wang, Y. Wei, F. Gao, L. Xie, G. Jia, W. Wu, B. Ji. Blueberry anthocyanins: Protection against ageing and light-induced damage in retinal pigment epithelial cells. Br. J. Nutr. 2012 108(1):16 - 27.

H. Ohguro, I. Ohguro, M. Katai, S. Tanaka. Two-year randomized, placebo-controlled study of black currant anthocyanins on visual field in glaucoma. Ophthalmologica. 2012 228(1):26 - 35.

K. J. Ciuffreda, B. Vasudevan. Nearwork-induced transient myopia (NITM) and permanent myopia--is there a link? Ophthalmic Physiol Opt. 2008 28(2):103 - 114.

J. Garrard, S. Harms, L. E. Eberly, A. Matiak. Variations in product choices of frequently purchased herbs: Caveat emptor. Arch. Intern. Med. 2003 163(19):2290 - 2295.

C. Artaria, R. Pace, G. Maramaldi, G. Appendino. Different brands of bilberry extract: A comparison of selected components. Nutrafoods. 2007 6(4):13-18.

B. R. Hammond Jr, K. Fuld, D. M. Snodderly. Iris color and macular pigment optical density. Exp. Eye Res. 1996 62(3):293 - 297.

S. Beatty, I. J. Murray, D. B. Henson, D. Carden, H. Koh, M. E. Boulton. Macular pigment and risk for age-related macular degeneration in subjects from a Northern European population. Invest. Ophthalmol. Vis. Sci. 2001 42(2):439 - 446.

A. J. Wenzel, C. Gerweck, D. Barbato, R. J. Nicolosi, G. J. Handelman, J. Curran-Celentano. A 12-wk egg intervention increases serum zeaxanthin and macular pigment optical density in women. J. Nutr. 2006 136(10):2568 - 2573.

B. R. Hammond Jr, E. J. Johnson, R. M. Russell, N. I. Krinsky, K. J. Yeum, R. B. Edwards, D. M. Snodderly. Dietary modification of human macular pigment density. Invest. Ophthalmol. Vis. Sci. 1997 38(9):1795 - 1801.

J. R. Sparrrow, D. Hicks, C. P. Hamel. The retinal pigment epithelium in health and disease. Curr Mol Med. 2010 10(9):802-823.

C. Y. Cheng, W. Y. Chung, Y. T. Szeto, I. F. F. Benzie. Fasting plasma zeaxanthin response to Fructus barbarum L. (Wolfberry; Kei Tze) in a food-based human supplementation trial. Br. J. Nutr. 2005 93(1):123 - 130.

P. Bucheli, K. Vidal, L. Shen, Z. Gu, C. Zhang, L. E. Miller, J. Wang. Goji berry effects on macular characteristics and plasma antioxidant levels. Optom Vis Sci. 2011 88(2):257 - 262.

H. Nakaishi, H. Matsumoto, S. Tominaga, M. Hirayama. Effects of black current anthocyanoside intake on dark adaptation and VDT work-induced transient refractive alteration in healthy humans. Altern Med Rev. 2000 5(6):553-562.

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I. Ohguro, H. Ohguo, M. Nakazawa. Effects of anthocyanins in black currant on retinal blood flow circulation of patients with normal tension glaucoma. A pilot study. Hirosaki Med. J. 2007 59:23-32.

Acknowledgements

Images thanks to Kattebelletje and Kirinqueen via Flickr and Sun Ladder, Aney, Theornamentalist, Ashlyak, Dinkum, OsvaldoGago and Kotovisk via Wikimedia Commons. Thanks to Ellen Reid for her image-finding expertise and Jeff Thomas for his Keynote help.

Transcript

Anyone who's ever got a sun burn knows how damaging the UV rays in sunlight can be. Imagine what those same rays are doing to the back of our eyeballs, our retinas. The eye is designed to take sunlight and focus it like a magnifying glass into the back of our eyes. Thankfully, we have a layer of cells in our eye called the retinal pigment epithelium that supports and protects our delicate retinal eyesight machinery. The layer builds up yellow plant pigments from our diet like zeaxanthin, which absorbs blue light and protects the retina from the photo-oxidative damage. The yellowing of our corneas when we get cataracts may actually be our body's defense mechanism to protect our retinas. In fact when you go and surgically remove those cataracts your risk of blindness from macular generation shoots up since you removed that protection. Instead of trading one type of vision loss for another, instead of pigmenting the front of your eye with cataracts, better to pigment the back of our eye through diet. The pigment in the back of our eye is entirely of dietary origin, thus suggesting that the most common cause of blind registration in the western world could be delayed, or even averted, with appropriate dietary modification.

Where in our diet do we get it? Well, the egg industry brags that eggs are a good source. But have six eggs a week for three months and the pigmentation in one’s eyes may barely move—and these were the high lutein free-range certified organic eggs not purchased at a supermarket, but a local farm.

Instead of getting the phytonutrients from the egg, that came from the chicken, that came from the corn and blades of grass she pecked on, what about getting it from the source—a cup of corn and a half cup of spinach a day for three months. A dramatic boost in protective eye pigment. Just to compare to the eggs, here’s the best that eggs can do. But if you cut out the middle hen, and get these nutrients from plants directly, you get up to here.

What's neat about this study is that they went back and measured the levels 3 months after the study stopped and levels were still way up here, so once you build your macular pigment up with a healthy diet, your eyeballs really try to hold on to it. Even if you go on vacation and end up eating more iceberg lettuce than spinach, your eyes will hold out until you get back.

Yes eggs can increase zeaxanthin levels in the blood, but they also raised bad cholesterol levels and risk of heart disease. "Therefore an egg yolk-based dietary strategy to increase plasma zeaxanthin cannot be recommended, and an alternative, cholesterol-free, food source is desirable, like goji berries for example, which have up to 60 times more zeaxanthin than eggs. A modest dose markedly increases levels in our body, an inexpensive, effective, safe, whole food strategy to increase zeaxanthin in the bloodstream. But we don't need it in our blood, we need it in our eyes.

So how about a double-blind randomized placebo-controlled trial? To preserve eyesight in the elderly in traditional Chinese medicine, people are often prescribed 40 to 100 goji berries a day, but here they just used about 15 berries a day for 3 months and still found it could protect against loss of pigment and prevent the buildup of what's called soft drusen, which is just debris that builds up in the back of the eye, both of which are associated with age-related macular degeneration, theleading cause of legal blindness in older men and women, affecting more than 10 million Americans. Note they gave it in milk here, so the butterfat could increase the absorption of these carotenoid pigments. A healthier way to get the same effect would just be to eat goji berries with nuts or seeds, in other words, goji trail mix.

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 Ariel Levitsky.

To help out on the site please email volunteer@nutritionfacts.org.

Dr. Michael Greger

Doctor's Note

I’ve previously touched on this important topic in Preventing Macular Degeneration with Diet. I’ve also covered other leading causes of blindness such as cataracts (Preventing Cataracts with Diet) and glaucoma (see my last video, Greens vs. Glaucoma, and my next video, Dietary Treatment of Glaucoma).

In Egg Industry Blind Spot I compare the levels in eggs to greens.

Though they didn’t appear to boost a measure of immune function (Boosting Natural Killer Cell Activity), goji berries are one of the most antioxidant-packed snacks out there. A tip on getting them inexpensively can be found in my video Are Goji Berries Good for You?

If you haven't yet, you can subscribe to my videos for free by clicking here.

  • Leslie

    Gogi berries are a nightshade, from what I have read. There are plenty of people who experience arthritic symptoms/pain, as well as other ailments, after ingestion of nightshade plants (potatoes, tomatoes, eggplant, tobacco, gooseberries, certain peppers, gogi berries and more). I do wonder if you have any information on this.

    • JohnC

      In case anyone is wondering, Indian gooseberry, or Amla, is not in the nightshade (Solanaceae) family.

      • wideEyedPupil

        Amla is everywhere in India, like oranges in Australia or US.

  • Calvin Leman

    Spinach only? What about Kale and Collards instead of spinach?

  • Arun Mukherjee

    I already have macular degeneration. I have switched to a healthy vegan diet. Would it help preventing further loss of vision in my case?

    • Alan

      If i was you i would stay on the vegan diet and find out. I do not believe that it could hurt anything.

    • Darryl

      The higher vegetable and fruit content of vegan diets approaches the nutrient & phytochemical supplement cocktail used in the Age Related Eye Disease 2 study: C (500 mg), E (400 mg). zinc (25 mg), copper (2 mg), lutein (10 mg), zeaxanthin (2 mg). Eat some kale and other dark greens (with a bit of salad oil, nuts, or avocado for improved absorption) regularly and your lutein intake will be much higher than that of the AREDS2 participants.

      If you have the “wet form” of macular degeneration, there has been some success with angiogenesis inhibitors in preventing abnormal growth of leaky blood vessels. Some plant compounds like catechins (from green tea), genistein (from soy), isothiocyanates and indole-3-carbinol (from cruciferous vegetables), quercetin (from onions), anthocyanins (berries & colored grains), and curcumin (from turmeric) inhibit angiogenesis, though they’re not as potent as the injectable (yes, into the eye) pharmaceutical inhibitors repurposed from cancer treatment.(Eylea, Lucentis, Avastin, and Macugen).

      • Arun Mukherjee

        Yes, I have wet AMD. Thank you Darryl for all the useful information.

  • Anne

    Thank you so much for ll of this power packed information…as soon as I get a little money together I am going to send you a check…it’s so hard to save up but you deserve it…

  • Nancy

    My 84-year old mother is living proof that improved diet can help stop wet macular degeneration at any age. She was diagnosed on her 80th birthday & started getting monthly injections, which worked well in stopped the progression of the disease. But who wants to get a shot in the eye every month? I finally convinced my mother to cut her meat & sugar consumption drastically, to eat more fruits & vegetables, AND to drink fresh vegetable juices and smoothies everyday. After just a couple of months, she got a pleasant surprise when her retina specialist told her didn’t need a shot that month. The same happened the following month, and then the next month, & so on. This January it will be 2 years since she’s needed a shot.

    Her retina specialist was so astounded & happy for her that he finally asked us what she’s been doing, which is nice because the average doctor usually just says, “Keep doing whatever you’re doing, but I don’t need to know about it.”

    • Alan

      Praise the Lord Nancy !!!!

    • Thea

      Nancy: Great story. Your mother is really lucky to have you!

      And one thumbs up for the specialist too. :-)

  • guest

    Most goji berries are from China (home to some of the worst air pollution on Earth). Is there research that has examined the heavy metal content and PCB content in China grown produce – even organic – compared to other less polluted countries?

    • Agnes Khoo Schwenk

      Grow your own goji berries. I’ve 2 goji berries, one red currant, 2 blueberries and will be growing more berries this year. Namaste and Happy New Year 2014.

  • guest

    How do the same protective foods you have highlighted here compare to those found in fish and shellfish? Is the plant group “stronger” than the fish/shellfish, or is it the other way around? I’ll keep looking online for info. on this but I hope someone here has knowledge to provide clarity on this.

    • guest

      ….Also, i didn’t want to list a bunch of sources showing that fish/shellfish can be good for macular degeneration, as this is a vegan website, but I hope the good Doctor (or someone else) can point out if this is not accurate.

      • Thea

        I don’t know whether first can be helpful or not. However, I think this is where it is very important to look at the whole food. We don’t want to get one benefit at the expense of our health in X many other ways.

        In other words, there is ample evidence that fish cause a great many health problems. So, if you can get the benefit without the greater risk from plants, that would be the way to go.

        If interested, see the videos/links on the following page to start to get an idea of why fish is not healthy over-all:

        http://nutritionfacts.org/topics/fish/

        I hope that helps put things into perspective for you.

      • TaxpayerX

        I thought this website’s mission was to provide science based nutritional information rather than to be a vegan advocacy website. Start picking and choosing information presented based on diet ideology and credibility will be lost.

        • Nancy

          This website does provide science based nutritional information. I think this website points people in the direction of eating a more whole foods, plant-based diet, which I think is different from veganism.

      • Darryl

        The carotenoid astaxanthin is found in krill (12 mg/100 g) and arctic shrimp (120 mg/100 g) and also crosses the blood/retina barrier. Its about 60% more potent as a singlet oxygen quencher than zeaxanthin, but personally, I’d prefer eating 17 g dried goji to 100 g krill to get the same effect.

        Farmed salmon is fed a pink yeast Phaffia rhodozyma originally found “exclusively in slime fluxes of certain broad-leafed trees”, to achieve a pink flesh color, but their astaxanthin content is less than 1 mg / 100 g.

  • DH

    Several people I have encouraged to go vegan for health reasons have been asking me about the utility of egg whites. I couldn’t find anything on the nutritionfacts.org website on egg whites, except that they do not appear to raise cholesterol. Are there any adverse health consequences?
    (personally, I would stay away for ethical reasons, but I realize most vegans adopt plant-based diets for a combination of health and ethical reasons)
    I did a detailed search on medline looking at egg whites, homocysteine and methionine and found nothing.
    I think that egg whites are promoted by several vegan diet doctors; again, other than the ethics (which is shoddy), are there any health downsides to this as a protein source?

    • Thea

      DH: Since egg whites are an animal product, there would be no such thing as doctor who promotes vegan diets telling people to eat egg whites.

      Concerning the health question: I mostly can only repeat what others on the team have said. But first my 2 cents: Since egg whites are almost pure animal protein, I think one of the biggest issues is IGF1 production in the body in response to eating it. (See the NutrtionFacts series on IGF1.) Also, if memory serves???, arachadonic (sp?) acid is still an issue. Plus, you can find plenty of evidence here on NutritionFacts about the problem with contaminated eggs sickening and killing a huge number of people every year. That would apply to the egg whites.

      Here is a quote from a post that Dr. Forrester recently did: “You do have to ask yourself why you would want to eat a high animal protein food given the evidence that too much protein intake especially animal protein is harmful to your kidney function and associated with certain cancers. Egg whites also have a very high amount of selenium. The devil is always in the details.”

      And here is one of my favorites quotes from Toxins on the issue of egg whites:

      “Here is why we should avoid egg whites:

      1. Egg whites are ridiculously high in the amino Acid Methionine. Rice has 14 times less of this amino acid and beans 7 time less. When one consumes Methionine in a large quantity (like that found in egg whites), it is broken down into sulfuric compounds. these sulfuric compounds are buffered by the calcium of the bones. the result, over time, is
      osteoporosis and kidney stones.

      http://www.vivalis.si/literatura/6a00.pdf

      2. Methionine is metabolized into homocysteine. This substance is a risk factor associated with heart attacks,
      strokes, peripheral vascular disease, venous thrombosis, dementia, Alzheimer’s disease, and depression.

      http://www.pnas.org/content/100/25/15089
      (this study was done with mice, not humans.)

      3. Cancer cell metabolism is dependent upon methionine being present in the diet; whereas normal cells can grow on a
      methionine-free diet feeding off other sulfur-containing amino acids.
      http://www.ncbi.nlm.nih.gov/pubmed/14585259
      http://www.ncbi.nlm.nih.gov/pubmed/12416254

      4. Good ol’ Insulin like growth factor is raised significantly by Methionine. raised levels of IGF-1 = accelerated aging/tumor promotion.
      http://www.ncbi.nlm.nih.gov/pubmed/12176673
      http://jnci.oxfordjournals.org/content/92/18/1472.abstract

      5. Sulfur from Methionine is known to be toxic to the tissues of the intestine, and to have harmful effects on the human
      colon, even at low levels, possibly causing ulcerative colitis.
      http://www.ncbi.nlm.nih.gov/pubmed/9448181
      http://www.ncbi.nlm.nih.gov/pubmed/8287651
      (this study done with rats)

      http://jnci.oxfordjournals.org/content/82/11/950.abstract

      6. Restriction of methionine in the diet has been shown to prolong the life of experimental animals.
      http://www.ncbi.nlm.nih.gov/pubmed/12543260
      http://jn.nutrition.org/content/10/1/63.short

      Also, egg whites are pure protein without any other nutrients, like antioxidants, fiber or carbs. Just as white flour is viewed as empty calories, so should egg whites.”

      • DH

        Thank you for that explanation.

        I view IGF-1, methionine, selenium, isolated protein — all as theoretical risks of egg whites, as there doesn’t seem to be any epidemiological data tying egg white consumption to adverse health outcomes (and thinking about it, any such data would be completely confounded by self-selection bias). Indeed, what studies I have seen on egg whites and cholesterol actually suggest fairly potent improvement of lipid atherogenic risk markers such as the total:HDL cholesterol ratio, which is a stronger predictor of vascular events than total, LDL or HDL cholesterol alone.

        As to renal dysfunction from high protein intake, I believe that one could do damage to your kidneys from excessive protein intake from any source (including isolated protein supplement powders).

        However, I personally will continue to avoid egg whites because 1) I don’t like frying my foods; and 2) the ethics of the egg-laying industry are horrific. I am also somewhat skeptical of all the additives listed on containers of egg whites.

        The most likely probability is that egg whites are much healthier than whole eggs, but perhaps not as healthy as a completely vegan diet. I just don’t know. A lot of the risks you’ve cited appear to be hypothetical and based on arguments of similarity (e.g. “we know methionine is bad in high doses…..egg whites contain a fair amount of methionine…. so even egg whites in small doses could be harmful”) rather than specificity (e.g. “a randomized trial of egg white consumption showed deleterious effects on arterial wall thickening” — such a study I have not seen, but could conceivably exist, as there are hundreds of medline-index articles on egg whites).

        I do not mean to sound skeptical. I only want to do the best possible for my patients. I usually don’t even mention egg whites, but it always seems to come up. Finally, if my memory serves me correctly, a large meta-analysis in the BMJ did not show any harm (or any benefit) to selenium supplementation — http://www.bmj.com/content/346/bmj.f10

        — in fact, there was a slight trend toward benefit for selenium-assigned patients. Also vegans tend to be very low on selenium.
        I am looking for a smoking gun and if I find it, I will share it. Personally, I would prefer beans to egg whites, but maybe that’s just me (it seems society has become obsessed with egg replacements, and many health-conscious “vegans” do eat egg whites).

        • Thea

          DH: I respect your opinion and think it is quite reasonable. However, I disagree/come to a different conclusion myself. For whatever it is worth, I wanted to share my thoughts.

          I find the IGF1 argument to be particularly compelling, and (as I understand it), the IGF1 issue applies equally to egg whites. Also, I think we have plenty of hard evidence that a whole plant food based diet is superior for human health. As shown on this website, deviations from that general ideal tend to lead to increased risk for various diseases. (I wish I had kept a list of all of Dr. Greger’s “moderation failed” videos.) Egg whites are neither a whole food nor a plant food. (I’m not sure why anyone would dispute this.) So, while there may not be a “smoking gun”, I think there is plenty of evidence as a whole to put egg whites in the “best to not eat” category.

          Your argument about egg whites being OK in small amounts is something that I would certainly agree with in principle, but strongly disagree with in practice. People want to know, “What foods promote health when eaten in desired quantities?” It is understood by most people that small amounts of just about anything is not going to hurt them. I could eat a candy bar three times a year and be just fine. But I understand that a candy bar is not a health food. I wouldn’t want my doctor to tell me that candy bars are OK, because he assumes that I will only have say one of them a year. If my doctor wants to talk about candy bars, I hope he will explain all the potential problems with candy bars and be very specific about what counts as a small amount. In other words, it is worthless information if my doctor says that something is fine to eat when he/she considers “everything” fine to eat because everything is fine in small amounts.

          Put another way: I think that even the most pro-whole-plant-food proponent on this site would agree that very small amounts of meat, dairy and eggs is probably not going to hurt the health of most people. But that doesn’t mean that those animal foods are health promoting or even neutral. In addition, while a small amount *may* be OK, there are good reasons to abstain rather than trying to find that line between a healthy amount and a non-healthy amount. For one thing, the “everything in moderation” argument is a huge fail. Everyone’s ideas of what counts as moderation are different and almost never evidence-based. What is moderation? What should be asked is, at what amounts do we have which risk levels? We often don’t have those answers.

          Finally, I think that most people who ask about egg whites are envisioning eating omelets, quiche, meringue, etc. In other words, they want to eat a lot, not a small amount at all.

          Some Perspective: When it comes to egg whites, we aren’t talking poison. Any health problems will be ones that build up over time, just like with meat. So, there isn’t going to be a smoking gun – just lots of messy data because nutrition science and biology is just so messy. (Messy meaning some studies will show one thing and others will show the opposite and sometimes they are all perfectly good studies.) To put this into perspective: Was there a smoking gun study that convinced you that smoking is bad for humans? Or was it all the evidence put together over time? What about those people who smoke a lot and don’t get cancer? What if you only smoked a small amount? How little smoking can one do and be “safe”? The answer is: we don’t really know. The “safe” amount is probably a different amount for every person. It is hard for people to smoke in amounts small enough that are likely to be safe since smoking is so addictive and we don’t have a defined “safe level”.

          Bottom line: If people want to maximize their likely health outcomes, they will just refrain from smoking. I would say that eating animal protein falls into the same category. There is enough messy evidence that eating animal protein unnecessarily increases our risk of getting diseases such as cancer without providing overall benefits. Because meat, dairy and eggs are so addictive (both in the sense of cravings and potential with drawl symptoms), best to stay away from animal foods.

          That’s just how I see it. As I said, I do understand your position and also respect it. You have a good point too.

          • DH

            Hi Thea,

            I don’t know enough about the IGF-I argument to render an opinion on it, but from one of the pubmed articles you linked to in your previous post, I found this statement interesting:

            “Evidence further suggests that certain lifestyles, such as one involving a high-energy diet, may increase IGF-I levels, a finding that is supported by animal experiments indicating that IGFs may abolish the inhibitory effect of energy restriction on cancer growth.”

            I am trying to understand what the link would be between egg whites, a high-energy diet and IGF-1. Are you saying this is tied through methionine?

            Agree that the “everything in moderation” argument fails on multiple levels for most people/patients, but I was referring only to a single food item (egg whites). If egg whites are like a gateway drug to blowing a big hole in a plant-based diet, then I concede that point, but I know plenty of people who consume egg whites against the background of a vegetarian diet. A colleague of mine strongly recommends that all egg yolks be replaced with egg whites.

            Yet I shouldn’t have used the phrase “egg whites in small doses”. If people think they are truly healthy, they are likely to overconsume them.

            The problem that I have is that I can’t seem to find any evidence, whether in vitro, in vivo animal data, human randomized trials, human observational studies, etc, that tie egg white consumption to adverse outcomes, even a single adverse biomarker. Someone on this website said that he avoided egg whites because they are high in methionine – to me, that’s not sufficient prima facie evidence to condemn egg whites, because methionine has not been accepted as a cardiovascular risk factor to the same degree that cholesterol, saturated fat or other “toxins” have (and remember – the dose makes the poison). I have specifically looked for papers on egg whites and methionine and found virtually nothing.

            Again it comes back to what to do when someone in whom I’ve recommended a vegan diet asks me whether they can drink skim milk or eat egg whites. A lot of people on omnivorous diets see starting veganism as a deprivation of all their favorite foods, and so they ask whether it is ok to put skim milk in their cereal or change their yolks to whites. Since egg whites appear to lower serum phosphorous and insulin levels, decrease total cholesterol and LDL cholesterol levels, and increase HDL cholesterol levels, the net impact of what literature I have seen is suggesting a positive benefit – at least on these biomarkers. Therefore, there would have to be a suggestion in the literature that they also have a net impact on deleterious risk factors that outweigh all of these factors. I will keep looking for it. Definitely we can say that egg whites are healthier than egg yolks. I am loathe to recommend any animal products for ethical reasons, and thus I am only answering the question about egg whites when it comes up (ie someone puts it forth).

          • Thule

            I wonder when I see people still talking about any real proofs linking animal protein (yes, the one in eggs whites included) specifically with cancer, and degenerative diseases, ever really knew about The China Study?

            All this was settled then, why this information isn’t everywhere by now? Read Whole, by the same author.

            There are several factors beyond methionine; if you didn’t yet, I suggest reading it.

          • DH

            I have read the original reports behind the China Study – i.e. the published, peer-reviewed articles. Perhaps you are referring to “egg protein” in general, rather than “egg whites”. Rural and urban Chinese at that time did not eat “egg whites” (why would they?). They ate whole eggs. That is very different than isolated lacto-albumin. Not only that, but from an epidemiological perspective, the China Study is considered weak evidence by many nutritional scientists – it was ecological and cross-sectional, rather than longitudinal and individual person-based.

            So the China Study tells me nothing about the healthiness of egg whites, unless you are lumping this all in under general “animal protein”, which is not a safe thing to do…..

          • http://www.DonForresterMD.com/ Don Forrester MD

            You are correct. There are limitations to any study. If you haven’t read Dr. Campbell’s new book, Whole, I would recommend it. It gives a perspective of the limitations of reductionistic studies in adaptive systems which is sobering. Most of the attacks I have read seem to me to continue to support the paradigm and research model of the pursuit of reductionistic studies. As important as they are I believe we need to shift to more balance funding to include studies appropriate for complex systems.

          • DH

            Actually there’s a new review in Am J Med extolling the virtues of the Mediterranean Diet (PREDIMED, Lyon Heart Trial) — http://www.sciencedirect.com/science/article/pii/S000293431301111X

            (Diets to Prevent Coronary Heart Disease 1957- 2013: What Have We Learned?)
            I read parts of Whole but could not get the ‘whole’ way through it. The first half of the book was a screed against the scientific community, mainstream nutritionists, and Dr Campbell’s critics. I understand his colleagues at Cornell sigh when his name is brought up – is that true?
            In the first part of the book he declares that milk causes cancer based on animal data; he later makes the point that animal data cannot possibly be used to tease out toxicological influences of synthetic pesticides. Do I see a contradiction there?
            Cross-sectional studies at the ecological level (no individual patient data, no longitudinal follow-up component, no randomization, no blinding). Animal studies selectively cited.
            I think he makes some great points but what I understand from my interactions with a number of nutritional scientists and practitioners (RD), even plant-based ones, is that he has taken what research evidence he has produced to an extreme of opinion. I believe that it is the lack of uncertainty that is dangerous here. Science is always uncertain and we can never know the full truth. Scientists, like the rest of us, should be willing to admit to this. Decrying one’s critics as reductionists is not an argument based on science or wisdom.
            (regardless, I am staying vegan and encouraging my patients to do the same; but I am not so sure that Dr T.C.C. is a great advocate for this cause)
            Please correct any of this if I am wrong.

          • Thule

            Part of the answer to that sort of critics by Dr Campbell:

            For the monograph, we were somewhat uncertain whether to publish such raw data but decided to do so for two principle reasons. First, we wanted to make these data available to other researchers, while hoping that data misuse would not be a significant problem. Second, because these data were collected in rural China at a time when data reliability might have been questioned, we chose to be as transparent as possible. We
            discussed data use and misuse on pp. 54-82 of the China Project
            monograph that curiously was overlooked by Masterjohn and Jay’Y’.

            In brief, while fully understanding the pitfalls, the purpose of
            interpreting data of this kind is to extract from these crude
            correlations their true correlation counterparts, then interpret these
            counterparts within the context of information derived from other
            sources. In making these adjustments and interpretations, we want to consider, for example, 1) whether there is a sufficiently broad range of exposure for each of the variables comprising the associations (e.g., a true
            association of breast cancer with dietary fat consumption can only be
            detected if there is a sufficient range—above zero—for each of these variables), 2) whether there are confounding factors (e.g., high fat consumption might reflect high animal protein consumption, low dietary fiber consumption or even ownership of TVS), 3) whether the associations are biologically plausible (e.g., being consistent with existing clinical information, especially within this clinical project) and 4) whether these associations collectively reflect a consistent dietary pattern, among other considerations. In addition to these individual associations, we also had opportunities to evaluate aggregate associations, keeping the same caveats and considerations in mind.

            These critics, who are mischievously posing as qualified scientists, have committed errors that expose either their ignorance of basic research principles and/or their passionate following of an unstated agenda. By superficially citing uncorrected crude correlations from the China Project monograph, they show a serious lack of understanding not
            only of the fundamentals of scientific research but also of the
            principles of statistics, epidemiology and nutrition. To make matters worse, they have selected correlations that reflect an alternative agenda or bias that has nothing to do with objective science.

            It was this suspicion of bias that reminded me of an eerily similar commentary earlier written by Ms. Sally Fallon, President of a special interest group located in Washington, DC, known as the Weston A. Price Foundation
            (WAPF). Ms. Fallon’s commentary was widely circulated in cyberspace
            several years before we published our book. Thus I began to wonder who was WAPF and especially who was Weston A. Price, now the adopted ‘patron saint’ of WAPF.

            —-

            Looks like you have been hearing the propaganda by that farmer’s lobby and related interest groups.

          • Thea

            DH: I just want to state again that I think your position is quite reasonable.

            If you are interested in learning about the health issues with IGF-1, Dr. Greger did a great series (of about 7 videos) on this topic starting here: (I can’t explain it as well as Dr. Greger.)
            http://nutritionfacts.org/video/igf-1-as-one-stop-cancer-shop/

            When it comes to eggs, there is also the issue of salmonella to consider, “the leading cause of food-borne illness related hospitalization and death in the United States.”
            http://nutritionfacts.org/video/total-recall/

            Your latest post is the one that I can relate to the most in this thread. It *is* very hard to counsel people who are *maybe* open to changing their behavior, but who can’t be pushed too hard.

            For what it’s worth, here is how I approach these conversations when I have them (only with people who are interested):
            “We don’t know everything about nutrition for humans, but the big picture evidence has been remarkably unchanged for decades. So, we have a pretty good idea that the diet which is the most health-promoting (disease fighting) is a whole plant food based diet fortified with B12 and possibly D. I can share some resources on what this diet really looks like if you are interested. I also have a DVD of Forks Over Knives that I highly recommend you watch.

            The issue is how to get to that ideal diet. Some people are motivated and go cold-turkey. There are three excellent reasons for going cold-turkey for a 3 week trial period… I can give you some support/resources on *how* to practically make this transition if you are interested.

            But some people can’t do cold-turkey. If you feel you can’t do it all at once, you might try starting out vegetarian and later take out the eggs and dairy. Or start by leaving out the dairy and eggs first. Other people start on the path to healthy eating by strictly eating healthy at home, but allowing other foods when eating out at restaurants or friend’s houses. Etc.

            This conversation works for me, because I’m not pressuring the other person to do more than he/she can, but I’m also not doing what our government and the media does all the time – try to soften the message about what is truly healthy to the point that the information about what foods are healthy becomes meaningless and causes great confusion and misinformation.

            That’s just my 2 cents. I understand that you disagree (at the moment anyway!) on the science behind egg whites and thus possibly on what you would describe as a health-promoting diet. I was moved to share my approach after reading what you wrote about counseling patients.

            Best of luck to you on walking your own path of being true to all your morals: from preventing animal abuse, to limiting global climate change, to limiting human starvation, to being truthful about healthy diets with your patients/other people. (I assume you are working to meet all these goals. Happily for myself, none of goals are in conflict.)

          • DH

            Thea, sorry to take so long to come back to this. I’ve just found a study showing that substitution of dietary fat by egg whites increasing urinary C-peptide excretion by 60%, which reflects 24 hour insulin exposure.

            http://www.ncbi.nlm.nih.gov/pubmed/8969280

            I believe this would be a very good health reason to avoid egg whites.

          • Thea

            DGH: Very interesting! Thanks!!

          • Ron

            Hi Thea – Since Dr. Ornish, in his Spectrum approach (which allows very small amounts of fat-free dairy, egg white, and fish oil), allows a small amount of egg whites, I thought I’d experiment a bit and try them, after pure plant-based for years. I found that my urine immediately smelled of sulfur every time I consumed them. They gave me a slight headache. Egg whites provided no benefit. I see no reason to eat them now!

          • Thea

            Ron: Great experiment! That’s sure a way to prove it to yourself. Thanks for sharing!!

  • Mark

    Ok, Goji is the focus of the study. How about a list of foods with similar positive effects?

    • Darryl

      Lutein + zeaxanthin content (mg / 100 g)
      dried goji 114.3
      kale 39.5
      spinach 12.2
      turnip greens 11.9
      Swiss chard 11.0
      mustard greens 9.9
      collards 8.9
      raddichio 8.8
      basil 5.6
      parsley 5.6

      corn 1.4
      eggs 0.3

      • guest

        I like the dried goji but someone above mentioned they are a member of the nightshade plant family – and I have to avoid all nightshades or I experience horrible joint pain. I do not know much about why this occurs in nightshades. Such a mystery to me but the side effects of ingesting our a real drag.

      • guest

        Looks like corn is an unimportant source of lutein/zeaxanthin. This is kinda a personal relief for me since most corn is genetically modified and so, I avoid eating it unless I can find some that’s organic. Trader Joe’s sometimes sells frozen organic corn, but lately I haven’t seen it. Does anyone know of a reliable source of organic or non-GMO corn?

        • Thea

          guest: According to the Trader Joe’s where I live, any product sold under their brand name is supposed to be free of GMO foods. So, if you can’t find their organic frozen corn, if they are selling any frozen corn under the TJ brand name, it should be free of GMO. Other than that, I would expect any health food type store where you live to have organic corn – which should be free of GMO. But I don’t know where you live. So, maybe you don’t have access to such a resource. Good luck.

    • Aaron Kester

      Individual foods may not be as important as overall dietary patterns. In this video (http://nutritionfacts.org/video/preventing-macular-degeneration-with-diet/) Dr. Greger shows that those who scored highest in the Alternative Healthy Eating Index developed by Harvard had the lowest risk overall of macular degeneration.

  • DH

    More on egg whites…

    Taylor LM, Kalantar-Zadeh K, Markewich T, Colman S, Benner D, Sim JJ, Kovesdy CP. J Ren Care. 2011 Mar;37(1):16-24. doi: 10.1111/j.1755-6686.2011.00212.x. Dietary egg whites for phosphorus control in maintenance haemodialysis patients: a pilot study. “Pasteurised liquid egg whites may be an effective diet component lowering serum phosphorus without risking malnutrition.”

    Housová J, Matoulek M, Svacina S, Kýhos K, Slabá S, Vavrejnová S, Ricarová B. Prague Med Rep. 2008;109(2-3):127-33. Comparisin of low energy breakfast based on special egg white spread product with a standard breakfast. “Egg white derived low calorie products have a beneficial effect on insulin response without any difference in ingested carbohydrate quantity.”

    Asato L, Wang MF, Chan YC, Yeh SH, Chung HM, Chung SY, Chida S, Uezato T, Suzuki I, Yamagata N, Kokubu T, Yamamoto S. J Nutr Sci Vitaminol (Tokyo). 1996 Apr;42(2):87-96. Effect of egg white on serum cholesterol concentration in young women. “The results indicate the favorable effects of egg white in the control of hypercholesterolemia.”

    Contaldo F, Di Biase G, Giacco A, Pacioni D, Moro CO, Grasso L, Mancini M, Fidanza F. Prev Med. 1983 Jan;12(1):138-43. Evaluation of the hypocholesterolemic effect of vegetable proteins. “Serum total and LDL cholesterol decreased during both diets but were statistically significant only on the egg-white diet.”

    I am not at all advocating egg whites but in aggregate the results of these four clinical trials suggest beneficial effects on insulin levels, serum phosphorous, total cholesterol, LDL cholesterol and HDL cholesterol. Thus any potential theoretical harm – e.g. from selenium, methionine, etc – (which I’ve been unable to find for egg whites in the literature) need to be weighed against the literature-documented benefits on these markers.

  • guest

    Cutting out the middle ‘hen’.

    Face palm. My funny bone needs some surgery. Groaning.

  • Jeffrey

    You ment to say the lens and not the cornea
    But otherwise as always a great discussion
    What about collard greens
    The population that eats the most has the least macular degeneration
    Thanks again for the outstanding work

  • befororewisdom

    Goji berries can be hard to get and often expensive. Are there more easily available, cheaper alternatives that work almost as well?

  • ksb935 .

    I had iridotomies in both eyes to control glaucoma. The iridotomies contributed to the development of cataracts in both eyes. My eye doctor said that the narrow angles were probably something I was born with, so diet would probably not have helped. I am vegan, and I take extra lutein every day via capsule. Sometimes, the treatment for one condition causes another medical issue. Very frustrating.

  • Hans

    0:47 “The yellowing of our corneas when we get cataracts” This needs a correction. Cataract is not yellowing of the cornea but of the crystalline lens which is situated behind the iris.

    Here is a link to the anatomy of the eye. http://www.webmd.com/eye-health/picture-of-the-eyes

  • phyllisjfitz

    I have macular degeneration. Yesterday the eye doc told me
    to start taking AREDS2, which I see contains copper. Copper,
    you said, can contribute to Alzheimers… What do you suggest?

    Thanks much!

  • Jonathan Zeif

    Maybe a stupid question but would corn chips and/or corn tortillas provide any benefit?

  • Bo

    https://www.youtube.com/watch?feature=player_embedded&v=QiieG5AqeUo#t=174 EYES can increase LDL-cholesterol? i agree – eating eyes is not particularly healthy.
    Love Dr. Greger!